Home
Info
Splash
TextTree
A1. NONMOTILE ALGAE WITHOUT CHLOROPLASTS:
CYANOBACTERIA
B1. VEGETATIVE CELLS USUALLY SOLITARY
C1. CELLS ATTACHED TO AQUATIC PLANTS (EPIPHYTIC)
D1. SOLITARY ELONGATED BASAL CELL ENCLOSED IN AN OPEN ENDED SHEATH, OFTEN WITH ONE OR MORE EXOCYTES (REPRODUCTIVE CELLS):
Chamaesiphon
D2. SOLITARY SHORT BASAL CELL ENCLOSED IN AN OPEN ENDED SHEATH, USUALLY WITH NUMEROUS EXOCYTES (REPRODUCTIVE CELLS):
Stichosiphon
D3. SOLITARY ELONGATED BASAL CELL (NOT IN SHEATH), USUALLY WITH ONE OR MORE EXOCYTES (REPRODUCTIVE CELLS):
Cyanophanon
D4. SOLITARY SHORT, CLUB-SHAPED BASAL CELL, WITH ONLY ONE EXOCYTE (REPRODUCTIVE CELL). ALTHOUGH TECHNICALLY SOLITARY, THE CELLS MAY FORM A DENSE CLUMP ON AQUATIC VEGETATION:
Geitleribactron
C2. CELLS SOLITARY UNLESS DIVIDING; NOT EPIPHYTIC:
Cyanothece
C3. CELLS SOLITARY OR IN SMALL COLONIES; COLONIES USUALLY FORMED FROM 2-4 CELL SUBGROUPS:
Chroococcus
C4. THICK WALLED RESTING CELLS:
akinetes
B2. VEGETATIVE CELLS UNITED INTO COLONIES
C1. CELLS ARRANGED IN A SINGLE LAYER FORMING FLAT COLONIES
D1. CELLS FORM GROUPS OF FOUR IN RECTANGULAR COLONIES:
Merismopedia
D2. CELLS TINY (<4 µm), SPHERICAL OR OVAL; BLUE-GRAY, IN SINGLE FLAT LAYER FORMING SPHERICAL, IRREGULAR, OR NET-LIKE (CLATHRATE) COLONIES:
Pannus
C2. CELLS ARRANGED IN CUBICAL COLONIES
D1. SMALL SPHERICAL CELLS IN DENSE, CUBICAL COLONIES:
Eucapsis
D2. CELLS IN GROUPS OF 2 OR 4; COLONIES OCCASIONALLY CUBICAL BUT USUALLY IN AMORPHOUS:
Chroococcus
D3. CELLS FORMING CUBICAL, SPHERICAL, OR IRREGULAR SUBGROUPS WITHIN LARGER COLONIES:
Microcystis
(in part)
C3. CELLS ARRANGED IN SPHERICAL OR NEARLY SPHERICAL COLONIES
D1. CELLS ATTACHED TO RADIATING MUCILAGE STRANDS
E1. CELLS SPHERICAL, IN GROUPS OF 2 OR 4 AT END OF THIN, RADIATING MUCILAGE STRANDS:
Snowella
E2. CELLS FORM AT END OF THICK, RADIATING MUCILAGE STRANDS; CELL DIVISION ALONG LONG AXIS FORMS HEART-SHAPED CELL PAIRS:
Gomphosphaeria
E3. CELLS FORM AT END OF THICK, RADIATING MUCILAGE STRANDS THAT ARE RARELY VISIBLE; INDIVIDUAL CELLS SPHERICAL OR OVAL, NOT HEART-SHAPED; MOST COMMON SPECIES IS DARK MOTTLED BROWN:
Woronichinia
D2. CELLS NOT ATTACHED TO RADIATING MUCILAGE STRANDS (STRANDS MAY BE PRESENT BUT INVISIBLE UNDER NORMAL MAGNIFICATION)
E1. CELLS APPEAR MOTTLED BROWN WHEN VIEWED UNDER THE MICROSCOPE
F1. CELLS SPHERICAL OR OVAL, DISTRIBUTED THROUGHOUT COLONY (NOT IN A SINGLE LAYER AROUND HOLLOW COLONY CENTER), WITH SOME SPECIES FORMING CUBICAL SUBGROUPS; COLONY SPHERICAL OR IRREGULAR (AMORPHOUS):
Microcystis
F2. CELLS FORM AT END OF THICK, RADIATING MUCILAGE STRANDS BUT THESE STRANDS ARE OFTEN NOT VISIBLE; INDIVIDUAL CELLS SPHERICAL OR OVAL; MOST COMMON SPECIES IS DARK MOTTLED BROWN:
Woronichinia
F3. FILAMENTS RADIATING FROM COMMON CENTER, FORMING SPHERICAL OR HEMISPHERICAL COLONIES:
Gloeotrichia
E2. CELLS GRAY OR BLUE-GREEN (NOT MOTTLED BROWN) WHEN VIEWED UNDER THE MICROSCOPE
F1. CELLS TINY (width <2 µm), ROD-SHAPED, PALE BLUE-GRAY; FORMING SHORT PSEUDOFILAMENTS INSIDE COLONY; COLONIES SPHERICAL, IRREGULAR, OR NET-LIKE (CLATHRATE):
Cyanodictyon
F2. CELLS TINY (<4 µm), SPHERICAL OR OVAL; BLUE-GRAY, IN SINGLE FLAT LAYER FORMING SPHERICAL, IRREGULAR, OR NET-LIKE (CLATHRATE) COLONIES:
Pannus
F3. CELL WIDTH ≥3 µm; SPHERICAL OR BROADLY OVAL, BRIGHT BLUE-GREEN; ARRANGED IN SINGLE LAYER AROUND HOLLOW COLONY CENTER; COLONIES SPHERICAL:
Coelosphaerium
and
Coelomoron
F4. CELLS SPHERICAL, OVAL, OR ELLIPTICAL, BLUE-GRAY, GRAY, GREEN, OR BROWNISH; LOOSELY DISTRIBUTED IN AMORPHOUS OR SPHERICAL COLONIES, USUALLY SURROUNDED BY DIFFUSE MUCILAGE:
Aphanocapsa
and
Aphanothece
F5. CELLS NARROWLY ELLIPTICAL, CYLINDRICAL, OR FUSIFORM; COLONIES COMPACT, SURROUNDED BY BROAD MUCILAGE:
Rhabdogloea
C4. CELLS ARRANGED INTO IRREGULAR, AMORPHOUS COLONIES
D1. CELLS APPEAR BROWN AND MOTTLED UNDER MICROSCOPE
E1. CELLS SPHERICAL OR OVAL; DISTRIBUTED THROUGHOUT COLONY (NOT FORMING SINGLE LAYER AROUND HOLLOW COLONY CENTER), WITH SOME SPECIES FORMING CUBICAL SUBGROUPS; COLONY SPHERICAL OR IRREGULAR (AMORPHOUS):
Microcystis
E2. CELLS FORM AT END OF THICK, RADIATING MUCILAGE STRANDS THAT ARE RARELY VISIBLE; COLONIES INITIALLY SPHERICAL, BECOMING IRREGULAR WITH AGE:
Woronichinia
D2. CELLS DO NOT APPEAR BROWN AND MOTTLED UNDER MICROSCOPE
E1. CELLS SPHERICAL OR OVAL
F1. CELLS SMALL (≤3 µm), SPHERICAL OR OVAL, BLUE-GRAY, IN SINGLE FLAT LAYER FORMING SPHERICAL, IRREGULAR, OR NET-LIKE (CLATHRATE) COLONIES:
Pannus
F2. CELLS FORM AT END OF THICK, RADIATING MUCILAGE STRANDS; MOST COMMON SPECIES IS DARK MOTTLED BROWN:
Woronichinia
(in part)
F3. COLONIES COMPRISED OF 2--16 CELL SUBGROUPS (USUALLY 4X); DIFFICULT, DIVERSE, AND INCOMPLETELY DESCRIBED GROUP:
Chroococcus
and
Limnococcus
F4. CELLS LOOSELY DISTRIBUTED IN AMORPHOUS OR SPHERICAL COLONIES, USUALLY SURROUNDED BY DIFFUSE MUCILAGE; USUALLY NOT IN SUBGROUPS OF 4X:
Aphanocapsa
F5. CELLS IN SUBGROUPS OF 2 OR 4, SURROUNDED BY THICK, STRIATED MUCILAGE:
Gloeocapsa
and
Gloeothece
E2. CELLS ELLIPTICAL, ROD-SHAPED, CYLINDRICAL, OR FUSIFORM
F1. CELLS ELLIPTICAL, OR ROD-SHAPED, PALE BLUE-GRAY; LOOSELY DISTRIBUTED IN AMORPHOUS COLONIES (NOT IN PSEUDOFILAMENTS), USUALLY SURROUNDED BY DIFFUSE MUCILAGE:
Anathece
and
Aphanothece
F2. CELLS TINY (width <2 µm), ROD-SHAPED, PALE BLUE-GRAY; FORMING SHORT PSEUDOFILAMENTS INSIDE COLONY; COLONIES SPHERICAL, IRREGULAR, OR NET-LIKE (CLATHRATE):
Cyanodictyon
F3. CELLS NARROWLY ELLIPTICAL, CYLINDRICAL, OR FUSIFORM; COLONIES ELONGATED, SURROUNDED BY BROAD MUCILAGE:
Rhabdoderma
F4. CELLS NARROWLY ELLIPTICAL, CYLINDRICAL, OR FUSIFORM; COLONIES COMPACT, SURROUNDED BY BROAD MUCILAGE:
Rhabdogloea
B3. VEGETATIVE CELLS ALIGNED END-TO-END FORMING FILAMENTS OR PSEUDOFILAMENTS
C1. CELLS ARE JOINED END-TO-END TO FORM TRICHOMES; TRICHOMES CONTAIN HETEROCYSTS
D1. TRICHOMES UNBRANCHED, LACKING BOTH FALSE AND TRUE BRANCHING; MAY BE STRAIGHT, CURVED, OR TWISTED
E1. TRICHOMES ENCLOSED IN RUBBERY MUCILAGE FORMING SPHERICAL OR OVAL COLONIES; MICROSCOPIC OR MACROSCOPIC COLONIES:
Nostoc
E2. TRICHOMES WITH HETEROCYSTS AT ONE OR BOTH ENDS (BASAL HETEROCYSTS)
F1. AT LEAST SOME OF THE TRICHOMES HAVE HETEROCYSTS ON BOTH ENDS, BUT MAY ALSO HAVE HETEROCYSTS ON ONE END OR SCATTERED (INTERCALARY); ALL TAXA ARE UNCOMMON OR NOT YET REPORTED FROM NORTHWEST WASHINGTON
G1. HETEROCYSTS SPHERICAL OR OVAL; CELLS SLIGHTLY LONGER THAN WIDTH; TRICHOMES TWISTED OR COILED:
Anabaenopsis
G2. HETEROCYSTS SPHERICAL OR OVAL, ON ONE OR BOTH ENDS OF TRICHOME OR SCATTERED (INTERCALARY); CELLS SHORTER THAN WIDTH; TRICHOMES STRAIGHT OR GENTLY CURVED; USUALLY FOUND IN WARM, BRACKISH WATER:
Nodularia
G3. HETEROCYSTS CONICAL, ON ONE OR BOTH ENDS OF TRICHOME; TRICHOMES STRAIGHT OR COILED; FOUND IN WARM, NUTRIENT RICH LAKES:
Raphidiopsis
F2. TRICHOMES UNTAPERED ACROSS ENTIRE LENGTH, WITH BASAL HETEROCYST AT ONE END; AKINETES, WHEN PRESENT, ADJACENT TO BASAL HETEROCYST:
Cylindrospermum
F3. TRICHOMES TAPERED, WITH BASAL HETEROCYSTS AT ONE END; AKINETES, WHEN PRESENT, ADJACENT TO BASAL HETEROCYST
G1. TRICHOMES RADIATING FROM COMMON CENTER, FORMING SPHERICAL OR HEMISPHERICAL COLONIES:
Gloeotrichia
G2. TRICHOMES MOSTLY SOLITARY, NOT RADIATING FROM COMMON CENTER; TRICHOME SURROUNDED BY SHEATH; OCCASIONALLY WITH FALSE-BRANCHING:
Calothrix
E3. TRICHOMES WITH INTERCALARY HETEROCYSTS (HETEROCYSTS SCATTERED ALONG TRICHOME)
F1. TRICHOMES STRAIGHT, SLIGHTLY TAPERED, CLUMPED INTO FLAKE-LIKE COLONIES:
Aphanizomenon
F2. TRICHOMES WITH BEAD-LIKE CELLS; TRICHOMES MAY BE STRAIGHT, GENTLY CURVED, SPIRALLING, OR TANGLED; SCATTERED HETEROCYSTS USUALLY ABUNDANT:
Anabaena
and
Dolichospermum
F3. HETEROCYSTS SPHERICAL OR OVAL, ON ONE OR BOTH ENDS OF TRICHOME OR SCATTERED (INTERCALARY); CELLS SHORTER THAN WIDTH; TRICHOMES STRAIGHT OR GENTLY CURVED; USUALLY FOUND IN WARM, BRACKISH WATER:
Nodularia
F4. TRICHOMES ENDOPHYTIC IN
Azolla
(MOSQUITOFERN) LEAVES:
Trichormus
D2. TRICHOMES WITH FALSE BRANCHING
E1. TRICHOMES TAPERED; FALSE BRANCHES HAVE ONE OR MORE HETEROCYSTS AT THE POINT OF BRANCH INITIATION; TRICHOMES ENCLOSED IN FIRM SHEATH:
Dichothrix
E2. TRICHOMES NOT TAPERED; FALSE BRANCHING, WITH ONE OR MORE HETEROCYSTS AT THE BASE OF EACH BRANCH
F1. TRICHOMES UNTAPERED; FALSE BRANCHES HAVE ONE OR MORE HETEROCYSTS AT THE POINT OF BRANCH INITIATION; TRICHOMES SURROUNDED BY THICK MUCILAGE, WITH MULTIPLE TRICHOMES IN COMMON SHEATH:
Coleodesmium
F2. TRICHOMES UNTAPERED; FALSE BRANCHES HAVE ONE OR MORE (USUALLY MORE) HETEROCYSTS AT THE POINT OF BRANCH INITIATION; TRICHOMES USUALLY SOLITARY, SURROUNDED BY THIN SHEATH:
Tolypothrix
E3. FALSE BRANCH DOES NOT HAVE HETEROCYSTS AT THE POINT OF BRANCH INITIATION:
Scytonema
D3. TRICHOMES FORM TRUE BRANCHES; TRICHOMES MAY BE UNISERIATE (ONE CELL WIDE) OR MULTISERIATE (TWO OR MORE CELLS WIDE)
E1. CELLS SPHERICAL, OVAL, OR BARREL-SHAPED; MAIN TRICHOME USUALLY MULTISERIATE (MORE THAN ONE WELL WIDE):
Stigonema
(in part)
E2. CELLS CYLINDRICAL OR BARREL-SHAPED; TRICHOMES MOSTLY MONOSERIATE (ONE CELL WIDE), SURROUNDED BY CLEAR, DIFFUSE MUCILAGE:
Hapalosiphon
and
Fischerella
E3. CELLS OVAL OR SHORT, ROUNDED RECTANGULAR (L<W); TRICHOMES MOSTLY MONOSERIATE (ONE CELL WIDE), SURROUNDED BY FIRM, YELLOWISH MUCILAGE:
Stigonema
(in part)
C2. CELLS ARE JOINED END-TO-END TO FORM TRICHOMES; TRICHOMES DO NOT CONTAIN HETEROCYSTS
D1. TRICHOMES ARE ATTACHED TO AQUATIC PLANTS (EPIPHYTIC) OR ASSOCIATED WITH ZOOPLANKTON MUCILAGE (ENDOGLOEIC)
E1. TRICHOMES VERY SHORT (<10 CELLS), EMBEDDED IN ROTIFER OR ALGAE MUCILAGE (ENDOGLOEIC):
Pseudanabaena
E2. SOLITARY ELONGATED BASAL CELL ENCLOSED IN AN OPEN ENDED SHEATH, USUALLY WITH ONE OR MORE EXOCYTES (SPORE-LIKE REPRODUCTIVE CELLS):
Chamaesiphon
E3. SOLITARY SHORT BASAL CELL ENCLOSED IN AN OPEN ENDED SHEATH, USUALLY WITH NUMEROUS EXOCYTES (SPORE-LIKE REPRODUCTIVE CELLS):
Stichosiphon
E4. SOLITARY ELONGATED BASAL CELL (NOT IN SHEATH), USUALLY WITH ONE OR MORE EXOCYTES (SPORE-LIKE REPRODUCTIVE CELLS):
Cyanophanon
E5. SOLITARY SHORT, CLUB-SHAPED BASAL CELL, WITH ONLY ONE EXOCYTE (SPORE-LIKE REPRODUCTIVE CELLS):
Geitleribactron
D2. TRICHOMES ARE NOT EPIPHYTIC OR ENDOGLOEIC
E1. TRICHOMES ARE SPIRALLING OR COILED AND USUALLY HIGHLY MOTILE:
Arthrospira
and
Spirulina
E2. MULTIPLE TRICHOMES ENCLOSED IN A WIDE, COMMON MUCILAGE:
Microcoleus
E3. CELLS VERY SHORT RELATIVE TO WIDTH (COIN-LIKE); TRICHOMES WIDE AND MOSTLY UNTAPERED (MAY HAVE SLIGHTLY TAPERED TERMINAL CELL)
F1. TRICHOMES LACK A SHEATH (CHECK CAREFULLY - SHEATH MAY BE INCONSPICUOUS); DIVERSE GROUP UNDERGOING TAXONOMIC REVISIONS:
Oscillatoria
and
Tenebriella
F2. TRICHOMES SURROUNDED BY A THIN SHEATH (CHECK CAREFULLY - SHEATH MAY BE INCONSPICUOUS); DIVERSE GROUP UNDERGOING TAXONOMIC REVISIONS:
Limnoraphis
and
Lyngbya
E4. CELLS CUBICAL, CYLINDRICAL, OR OVAL; ISODIAMETRIC (L=W), OR SLIGHTLY SHORTER OR LONGER THAN WIDTH (NOT COIN-LIKE)
F1. TRICHOMES NARROW (<5 µm wide), WITH TAPERED, HOOKED APEX; CELLS LONGER THAN WIDE, WITH GRANULAR CROSS-WALLS:
Geitlerinema
F2. TRICHOMES UNTAPERED; CELLS WITH DEEPLY CONSTRICTED CROSS-WALLS
G1. TRICHOMES VERY SHORT, WITH NO VISIBLE SHEATH; CELLS COMPRESSED (W>L) WITH CONSTRICTED CROSS-WALLS:
Borzia
and
Komvophoron
G2. CELLS OVAL OR CYLINDRICAL, WITH CONSTRICTED CROSS-WALLS; CELL LENGTH ≥ WIDTH:
Johanseninema
and
Pseudanabaena
F3. CELLS CUBICAL OR CYLINDRICAL; ISODIAMETRIC (L=W), OR SLIGHTLY SHORTER OR LONGER THAN WIDTH (NOT COIN-LIKE)
G1. TRICHOMES WITH THICK, STRIATED SHEATH; ABRUPTLY TAPERED NEAR APEX; USUALLY IN DENSE MATS:
Schizothrix
G2. TRICHOMES SURROUNDED BY A THIN SHEATH (CHECK CAREFULLY - SHEATH MAY BE INCONSPICUOUS); FILAMENT (TRICHOME AND SHEATH) ARE MOSTLY UNTAPERED, OR ONLY TAPERED NEAR THE APEX; DIVERSE GROUP UNDERGOING TAXONOMIC REVISIONS:
Lyngbya
(in part),
Planktolyngbya
,
Phormidium
, and similar
G3. TRICHOMES WITHOUT SHEATH; CELLS CYLINDRICAL, ISODIAMETRIC (L=W), KERITOMIZED (NET-LIKE), APPEARING NEARLY EMPTY:
Tychonema
G4. TRICHOMES LACK A SHEATH (CHECK CAREFULLY - SHEATH MAY BE INCONSPICUOUS); CELLS CYLINDRICAL, ISODIAMETRIC (L=W), OR SLIGHTLY LONGER OR SHORTER THAN WIDTH (NOT COIN-LIKE):
Phormidium
,
Planktothrix
, and similar
C3. CELLS FORM PSEUDOFILAMENTS WHERE INDIVIDUAL CELLS ARE ALIGNED END-TO-END BUT NOT JOINED ACROSS THE END WALL
D1. CELLS NARROWLY ELLIPTICAL, CYLINDRICAL, OR FUSIFORM; COLONIES ELONGATED, SURROUNDED BY BROAD MUCILAGE:
Rhabdoderma
D2. CELLS TINY (width <2 µm), PALE BLUE-GRAY, ROD-SHAPED; FORMING PSEUDOFILAMENTS THAT OFTEN CLUMP INTO SPHERICAL, IRREGULAR, OR NET-LIKE (CLATHRATE) COLONIES:
Cyanodictyon
A2. NONMOTILE ALGAE WITH CHLOROPLASTS
B1. CELLS USUALLY SOLITARY
C1. CELLS ENCLOSED IN RIGID LORICA, TEST, OR THICK WALLED CYST
D1. CELLS PLANKTONIC; ENCLOSED IN RIGID LORICA WITH LONG APICAL AND POSTERIOR SPINES:
Bitrichia
D2. THICK WALLED CELLS PRODUCED AT END OF GROWTH CYCLE; USUALLY FOUND WITH DECOMPOSING VEGETATIVE CELLS OF THE SAME SPECIES:
Cysts, zygotes, and other resting cells
C2. CELLS SPHERICAL, OVAL, ELLIPTICAL, OR LEMON-SHAPED IN OUTLINE
D1. CELLS SPHERICAL OR NEARLY SPHERICAL; CELL WALL MAY BE THICK BUT CELLS ARE NOT SURROUNDED BY VISIBLE MUCILAGE LAYER
E1. CELLS ROUGHLY SPHERICAL IN OUTLINE, WITH FLEXIBLE WALLS AND LONG, THIN PSEUDOPODS; CELLS MAY EXHIBIT AMOEBOID MOVEMENT:
Chrysamoeba
and
Rhizochrysis
E2. CELLS SPHERICAL WITH MANY LONG THIN SPINES; CHLOROPLAST CONTAINS LARGE CENTRAL PYRENOID WITH STARCH RING:
Golenkinia
E3. CELLS VERY LARGE, SPHERICAL, WITH MANY SMALL CHLOROPLASTS ATTACHED TO INTERNAL STRANDS OF MUCILAGE RADIATING FROM CENTER OF CELL:
Eremosphaera
E4. CELLS SPHERICAL, BRIGHT GOLDEN BROWN, WITH RED EYESPOT:
Hypnodinium
E5. SPHERICAL OR NEARLY SPHERICAL, DULL OR BRIGHT GREEN CELLS WITH DENSE (NOT STAR-SHAPED) CHLOROPLAST; SOLITARY OR IN SMALL TO LARGE SIZED COLONIES; CELLS MAY OR MAY NOT BE SURROUNDED BY MUCILAGE; COLONIES USUALLY SURROUNDED BY DIFFUSE MUCILAGE:
Sphaerocystis
E6. SPHERICAL CELLS LACKING A VISIBLE MUCILAGE LAYER AND OTHER DISTINCTIVE FEATURES; CELLS STAIN DARK BROWN IN LUGOL'S SOLUTION INDICATING PRESENCE OF STARCH:
nonmotile single cell green algae
(
Chlorococcum
,
Chlorella
, and others)
D2. CELLS SPHERICAL OR NEARLY SPHERICAL (BROADLY OVAL) IN OUTLINE AND SURROUNDED BY MUCILAGE LAYER
E1. CELLS SPHERICAL, GOLDEN BROWN, SOLITARY OR PAIRED; SURROUNDED BY STRIATED MUCILAGE:
Gloeodinium
E2. CELLS SPHERICAL, YELLOWISH GREEN, WITH RED PIGMENT DROPLET; SOLITARY OR IN SMALL COLONIES SURROUNDED BY DIFFUSE BUT (USUALLY) VISIBLE MUCILAGE:
Chlorobotrys
E3. SPHERICAL OR OVAL, BRIGHT GREEN CELLS WITH STAR-SHAPED CHLOROPLAST RADIATING FROM CENTRAL PYRENOID; SOLITARY OR IN SMALL COLONIES SURROUNDED BY DIFFUSE BUT (USUALLY) VISIBLE MUCILAGE:
Asterococcus
E4. SPHERICAL OR NEARLY SPHERICAL, BRIGHT GREEN CELLS WITH DENSE (NOT STAR-SHAPED) CHLOROPLAST; SOLITARY OR IN SMALL COLONIES SURROUNDED BY NARROW MUCILAGE LAYER:
Planktosphaeria
E5. SPHERICAL OR NEARLY SPHERICAL, DULL OR BRIGHT GREEN CELLS WITH DENSE (NOT STAR-SHAPED) CHLOROPLAST; SOLITARY OR IN SMALL TO LARGE SIZED COLONIES; CELLS MAY OR MAY NOT BE SURROUNDED BY MUCILAGE; COLONIES USUALLY SURROUNDED BY DIFFUSE MUCILAGE:
Sphaerocystis
D3. CELLS OVAL, ELLIPTICAL, OR LEMON-SHAPED; CELL MAY OR MAY NOT BE SURROUNDED BY MUCILAGE; ALSO CHECK SPHERICAL SECTION FOR BROADLY OVAL CELLS
E1. CELLS OVAL OR ELLIPTICAL, WITH LONG SETAE OR SPINES; SOLITARY OR IN SMALL COLONIES ENCLOSED IN OLD PARENT CELL WALL:
Lagerheimia
E2. CELLS BROADLY OVAL; SOLITARY OR IN SMALL COLONIES ENCLOSED IN GELATINIZED PARENT CELL WALL:
Oonephris
E3. CELLS OVAL, ELLIPTICAL, OR LEMON-SHAPED; SOLITARY OR IN SMALL COLONIES ENCLOSED IN EXPANDED PARENT CELL WALL:
Oocystis
E4. CELLS OVAL OR ELLIPTICAL AND BRIGHT BLUE-GREEN; SOLITARY OR IN SMALL COLONIES ENCLOSED IN OLD PARENT CELL WALL:
Glaucocystis
E5. SPHERICAL OR OVAL, BRIGHT GREEN CELLS WITH STAR-SHAPED CHLOROPLAST RADIATING FROM CENTRAL PYRENOID; SOLITARY OR IN SMALL COLONIES SURROUNDED BY DIFFUSE BUT (USUALLY) VISIBLE MUCILAGE:
Asterococcus
C3. CELLS CLUB-SHAPED, CRESCENT-SHAPED, ELLIPTICAL, OR FUSIFORM IN OUTLINE
D1. CELLS CLUB-SHAPED IN OUTLINE
E1. CELLS CLUB-SHAPED OR BROADLY FUSIFORM WITH LONG APICAL SPINE AND A SHORT, SPLIT (BIFURCATE) POSTERIOR SPINE:
Ankyra
(in part)
E2. CELLS CLUB-SHAPED OR BROADLY FUSIFORM WITH MANY LONG APICAL BRISTLES AND A SHORT, SPLIT (BIFURCATE) POSTERIOR SPINE:
Paradoxia
E3. CELLS CLUB-SHAPED OR CYLINDRICAL; SOLITARY OR IN TREE-LIKE COLONIES WITH CELLS FORMING AT END OF ELONGATED PARENT CELL:
Ophiocytium
D2. CELLS BROADLY OR NARROWLY CRESCENT-SHAPED; GENTLY OR STRONGLY CURVED
E1. CELLS CRESCENT-SHAPED (GENTLY CURVED) WITH LONG, SLIGHTLY CURVED APICAL SPINE AND POSTERIOR SPINES:
Ankyra
(in part)
E2. CELLS CRESCENT-SHAPED (GENTLY CURVED) WITH STOUT APICAL AND POSTERIOR SPINES; USUALLY EPIZOIC, OFTEN ON
DAPHNIA
:
Korshikoviella
E3. CELLS BROADLY CRESCENT-SHAPED, GOLDEN BROWN, WITH RED PIGMENT SPOT; OFTEN EPIPHYTIC:
Cystodinium
E4. CELLS BROADLY CRESCENT-SHAPED AND OFTEN ASYMMETRIC, WITH SHORT, BLUNT APICAL AND POSTERIOR SPINES; CHLOROPLAST DULL GREEN WITH LARGE PYRENOID:
Keratococcus
D3. CELLS BROADLY OR NARROWLY FUSIFORM IN OUTLINE
E1. CELLS BROADLY FUSIFORM OR CYLINDRICAL; RIBBON-LIKE SPIRALLING CHLOROPLAST(S) OR DENSE CHLOROPLAST WITH REDDISH END CAPS:
Spirotaenia
and
Tortitaenia
E2. CELLS CLUB-SHAPED OR BROADLY FUSIFORM WITH MANY LONG APICAL BRISTLES AND A SHORT, SPLIT (BIFURCATE) POSTERIOR SPINE:
Paradoxia
E3. CELLS NARROWLY OR BROADLY FUSIFORM WITH LONG APICAL SPINE AND POSTERIOR SPINES; POSTERIOR SPINES MAY BE SPLIT (BIFURCATE) OR END IN LEAF-LIKE STRUCTURE
Ankyra
and
Lanceola
E4. CELLS BROADLY OR NARROWLY FUSIFORM; SOLITARY OR IN LENS-SHAPED COLONIES WITH CELLS OFFSET AND ALIGNED ALONG LONG AXIS; CELLS AND COLONIES ENCLOSED IN LENS-SHAPED MUCILAGE:
Elakatothrix
and
Fusola
E5. CELLS FUSIFORM OR CYLINDRICAL; SOLITARY OR IN IRREGULARLY SPHERICAL COLONIES; CELLS ALIGNED ALONG LONG AXIS FORMING BUNDLES; COLONIES SURROUNDED BY DIFFUSE MUCILAGE:
Quadrigula
E6. CELLS NARROWLY FUSIFORM; SOLITARY; LACKING ANY VISIBLE MUCILAGE LAYER; MAY FORM BLOOMS:
Koliella
,
Monoraphidium
,
Schroederia
, and similar
D4. CELLS ELLIPTICAL OR CYLINDRICAL IN OUTLINE
E1. CELLS CYLINDRICAL, SOLITARY, STRAIGHT OR SLIGHTLY CURVED; LONG APICAL AND POSTERIOR SPINES:
Centritractus
E2. CELLS CYLINDRICAL (OR CLUB-SHAPED); SOLITARY AND COILED OR IN TREE-LIKE COLONIES WITH CELLS FORMING AT END OF ELONGATED PARENT CELL:
Ophiocytium
E3. CELLS BROADLY FUSIFORM OR CYLINDRICAL; RIBBON-LIKE SPIRALLING CHLOROPLAST(S) OR DENSE CHLOROPLAST WITH REDDISH END CAPS:
Spirotaenia
and
Tortitaenia
E4. CELLS FUSIFORM OR CYLINDRICAL; SOLITARY OR IN IRREGULARLY SPHERICAL COLONIES; CELLS ALIGNED ALONG LONG AXIS FORMING BUNDLES; COLONIES SURROUNDED BY DIFFUSE MUCILAGE:
Quadrigula
C4. CELLS ANGULAR IN OUTLINE WITH THREE OR MORE SIDES
D1. CELLS 3-SIDED (TRIRADIATE) WITH LONG, STRAIGHT SPINES AT EACH ANGLE:
Treubaria
D2. CELLS WITH 4-5 SIDES; FLATTENED (RECTANGULAR OR PENTAGONAL; NOT TETRAHEDRAL)
E1. CELLS VERY SMALL; RECTANGULAR OR PENTAGONAL (4-5 SIDES); FLATTENED; USUALLY WITH CONCAVE SIDES AND SHORT KNOBS OR TEETH AT ANGLES:
Tetraedron
E2. CELLS MODERATELY LARGE AND SHOWY WITH 4 LONG, REPEATEDLY BRANCHED ARMS:
Isthmochloron
D3. CELLS 4 OR MORE SIDES; NOT FLATTENED; MOSTLY TETRAHEDRAL
E1. CELLS 4-SIDED (TETRAHEDRAL) WITH SHORT SPINES AT EACH ANGLE; GOLDEN BROWN; OFTEN EPIPHYTIC:
Tetradinium
E2. CELLS 6-SIDED (HEXAGONAL), GOLDEN BROWN, WITH SMOOTH, THICK WALLS:
Torviella
cyst
E3. CELLS HIGHLY BRANCHED, NEARLY SPHERICAL, BRIGHT YELLOWISH GREEN:
Pseudostaurastrum
(in part)
E4. CELLS IRREGULARLY TETRHEDRAL AND STRONGLY TWISTED, WITH SHORT ANGULAR TEETH; BRIGHT YELLOWISH GREEN:
Tetraplektron
E5. CELLS IRREGULARLY TETRHEDRAL WITH EVENLY PITTED SURFACE; BRIGHT YELLOWISH GREEN:
Tetradriella
B2. NONMOTILE COLONIES WITH TWO OR MORE CELLS
C1. CELLS FLATTENED, FORMING RIBBON-LIKE CHAINS, SHORT CYLINDERS, OR PLATE-LIKE GROUPS OF CELLS
D1. COLONIES JOINED ON LONG AXIS TO FORM FLAT RIBBON-LIKE COLONIES (SINGLE ROW) OR PLATE-LIKE COLONIES (DOUBLE ROWS)
E1. CELLS FUSIFORM OR CRESCENT-SHAPED; APEX ACUTELY POINTED, WITHOUT SPINES BUT SOMETIMES WITH ROUNDED KNOBS; COLONIES TWISTED IN SOME SPECIES:
Tetradesmus
E2. CELLS ELLIPTICAL, CYLINDRICAL, OR OVAL; APEX ROUNDED, WITHOUT SPINES, TEETH, OR KNOBS:
Scenedesmus
and
Comasiella
E3. CELLS OVAL, ELLIPTICAL, CYLINDRICAL, OR FUSIFORM; CELLS WITH SPINES, TEETH, OR GRANULATIONS (NOT COMPLETELY SMOOTH):
Desmodesmus
and
Scenedesmus
(in part)
D2. CELLS FORM DISTINCT GROUPS OF 4; COLONIES MOSTLY RECTANGULAR IN OUTLINE
E1. RECTANGULAR 4-CELL COLONIES WITH FLATTENED, WEDGE-SHAPED CELLS; SOME TAXA MAY ALSO HAVE 8-CELL SPHERICAL COLONIES WITH WEDGE-SHAPED CELLS
F1. APEX OF EACH WEDGE-SHAPED CELL IS FLAT:
Lemmermannia
F2. APEX OF EACH WEDGE-SHAPED CELL IS DEEPLY INCISED:
Stauridium
E2. COLONIES COMPRISED OF 4-CELL GROUPS; CELLS BRIGHT GREEN, OVAL, ELLIPTICAL, OR BROADLY WEDGE-SHAPED:
Crucigenia
,
Crucigeniella
, and
Willea
E3. COLONIES COMPRISED OF 4-CELL GROUPS, FORMING IRREGULAR, SOMEWHAT RECTANGULAR CLUMPS; CELLS GOLDEN BROWN; USUALLY EPIPHYTIC:
Plaeoplaca
D3. COLONIES CIRCULAR OR OVAL IN OUTLINE; CELLS NOT IN DISTINCT GROUPS OF 4X
E1. CELLS ANGULAR AND STRONGLY FLATTENED; INNER AND OUTER CELLS DISSIMILAR:
Lacunastrum
,
Monactinus
,
Pediastrum
, and
Pseudopediastrum
E2. CELLS SPHERICAL, WITH FINE RHIZOPODIA, SURROUNDED BY WIDE, DIFFUSE MUCILAGE CONTAINING NUMEROUS TINY OIL DROPLETS:
Chrysostephanosphaera
C2. COLONIES SPHERICAL OR OVAL
D1. CELLS SPHERICAL, OVAL, OR LEMON-SHAPED
E1. CELLS BRIGHT GREEN; CELLS WILL TEST POSITIVE FOR STARCH
F1. CELLS SPHERICAL OR SLIGHTLY FLATTENED, WITH LONG, NONMOTILE PSEUDOCILIA; MOST COLONIES CONTAIN CELLS IN GROUPS OF 4
G1. CELLS SPHERICAL, WITH LONG, FLEXIBLE PSEUDOCILIA; LOOSELY ENCLOSED IN A CLUB-SHAPED OR SPHERICAL COLONIAL MUCILAGE; USUALLY EPIPHYTIC ON AQUATIC MACROPHYTES AND FILAMENTOUS ALGAE BUT OCCASIONALLY DISLODGED:
Apiocystis
G2. SPHERICAL CELLS WITH LONG, FLEXIBLE PSEUDOCILIA THAT EXTEND BEYOND COLONIAL MUCILAGE; CELLS FORM GROUPS OF 4 ENCLOSED IN MUCILAGE; ADDITIONAL MUCILAGE LAYERS MAY ENCLOSE MUITLPLE 4X GROUPS:
Paulschulzia
G3. CELLS SPHERICAL, WITH LONG, FLEXIBLE PSEUDOCILIA; CELLS FORM GROUPS OF 4, WITH MULTIPLE CELL GROUPS ENCLOSED IN COLONIAL MUCILAGE; SOME SPECIES FORM VERY LARGE, AMORPHOUS, GELATINOUS COLONIES:
Tetraspora
F2. CELLS SPHERICAL OR NEARLY SPHERICAL (NO PSEUDOCILIA)
G1. CELLS JOINED ALONG FLATTENED WALL SEGMENT OR SHORT WALL EXTENSIONS TO FORM HOLLOW COLONY:
Coelastrum
G2. CELLS FORM GROUPS OF 2-4 AT THE ENDS OF RADIATING MUCILAGE STRANDS:
Mucidosphaerium
G3. CELLS WITH STAR-SHAPED CHLOROPLAST RADIATING FROM CENTRAL PYRENOID; SOLITARY OR IN SMALL COLONIES SURROUNDED BY DIFFUSE BUT (USUALLY) VISIBLE MUCILAGE:
Asterococcus
G4. SPHERICAL OR NEARLY SPHERICAL CELLS WITH DENSE (NOT STAR-SHAPED) CHLOROPLAST; SOLITARY OR IN SMALL COLONIES SURROUNDED BY NARROW MUCILAGE LAYER:
Planktosphaeria
G5. SPHERICAL OR NEARLY SPHERICAL CELLS WITH DENSE (NOT STAR-SHAPED) CHLOROPLAST; SOLITARY OR IN SMALL TO LARGE SIZED COLONIES; CELLS MAY OR MAY NOT BE SURROUNDED BY MUCILAGE; COLONIES USUALLY SURROUNDED BY DIFFUSE MUCILAGE:
Sphaerocystis
F3. CELLS OVAL, BROADLY ELLIPTICAL, OR LEMON-SHAPED (NO PSEUDOCILIA)
G1. CELLS OVAL OR ELLIPTICAL, WITH LONG SETAE OR SPINES; SOLITARY OR IN SMALL COLONIES ENCLOSED IN OLD PARENT CELL WALL:
Lagerheimia
G2. CELLS BROADLY OVAL; SOLITARY OR IN SMALL COLONIES ENCLOSED IN GELATINIZED PARENT CELL WALL:
Oonephris
G3. CELLS OVAL, ELLIPTICAL, OR LEMON-SHAPED; SOLITARY OR IN SMALL COLONIES ENCLOSED IN EXPANDED PARENT CELL WALL:
Oocystis
E2. CELLS BRIGHT BLUE-GREEN, OVAL OR LEMON-SHAPED; SOLITARY OR ENCLOSED IN EXPANDED PARENT CELL WALL TO FORM SMALL OVAL COLONIES; OFTEN EPIPHYTIC:
Glaucocystis
E3. CELLS YELLOWISH GREEN, SPHERICAL, WITH RED PIGMENT DROPLET; SOLITARY OR IN SMALL COLONIES WITH 2-8 CELLS:
Chlorobotrys
E4. CELLS GOLDEN BROWN, SPHERICAL, SOLITARY OR IN SMALL 2-4 CELL COLONIES; COLONIES SURROUNDED BY STRIATED MUCILAGE:
Gloeodinium
D2. CELLS CYLINDRICAL, FUSIFORM, OR NARROWLY ELLIPTICAL
E1. CELLS CYLINDRICAL OR FUSIFORM; COLONIES USUALLY CONTAIN 8 CELLS RADIATING FROM CENTER TO FORM TETRAHEDRAL SHAPE:
Actinastrum
E2. CELLS NARROWLY FUSIFORM, ALIGNED LENGTHWISE INTO TANGLED LINEAR OR SPHERICAL COLONIES:
Ankistrodesmus
E3. CELLS CYLINDRICAL OR FUSIFORM; ALIGNED ALONG LONG AXIS, FORMING BUNDLES ENCLOSED IN DIFFUSE MUCILAGE; COLONIES IRREGULAR BUT MUCILAGE IS OFTEN SPHERICAL OR LENS-SHAPED:
Quadrigula
D3. CELLS ASYMMETRIC, BLUNTLY CRESCENT-SHAPED OR SAUSAGE-SHAPED; COLONIES USUALLY CONTAINING 4-8 CELLS SURROUNDED BY GELATINIZED PARENT CELL WALL:
Nephrocytium
D4. CELLS ANGULAR, WEDGE-SHAPED, OR IRREGULAR
E1. CELLS HEART-SHAPED OR WEDGE-SHAPED WITH APICAL EXTENSIONS; CELLS JOINED AT COLONY CENTER BY SHORT MUCILAGE STALKS (DIFFICULT TO SEE):
Sorastrum
E2. COLONIES FORMED FROM 4-CELL GROUPS JOINED BY MUCILAGE STRANDS; EACH 4-CELL GROUP CONTAINS 2 HEART-SHAPED CELLS AND 2 ELLIPTICAL CELLS:
Dimorphococcus
C3. COLONIES VARIOUS SHAPES OTHER THAN FLATTENED AND SPHERICAL/OVAL
D1. CELLS ENCLOSED IN RIGID VASE-LIKE OR CYLINDRICAL LORICA:
Epipyxis
D2. CELLS SPHERICAL OR BROADLY OVAL
E1. CELLS WITH ONE OR MORE LONG, NONMOTILE PSEUDOCILIA
F1. CELLS NEARLY SPHERICAL, WITH ONE FLATTENED SIDE WITH TUFTS LONG PSEUDOCILIA; CELLS LOOSELY ARRANGED IN AN IRREGULAR (AMORPHOUS) COLONY; PERSISTENT FRAGMENTS OF OLD CELL WALLS RETAINED WITHIN COLONY:
Schizochlamys
F2. CELLS SPHERICAL, WITH LONG, FLEXIBLE PSEUDOCILIA; LOOSELY ENCLOSED IN A CLUB-SHAPED COLONIAL MUCILAGE; USALLY EPIPHYTIC ON AQUATIC MACROPHYTES AND FILAMENTOUS ALGAE BUT OCCASIONALLY DISLODGED AND PLANKTONIC:
Apiocystis
F3. SPHERICAL CELLS WITH LONG, FLEXIBLE PSEUDOCILIA THAT EXTEND BEYOND COLONIAL MUCILAGE; SPHERICAL OR IRREGULAR (AMORPHOUS) COLONIES CONTAIN CELLS IN GROUPS OF 4 ENCLOSED IN MULTIPLE LAYERS OF MUCILAGE:
Paulschulzia
F4. CELLS SPHERICAL, WITH LONG, FLEXIBLE PSEUDOCILIA; CELLS FORM GROUPS OF 4, WITH MULTIPLE CELL GROUPS ENCLOSED IN COLONIAL MUCILAGE; SOME SPECIES FORM VERY LARGE, AMORPHOUS, GELATINOUS COLONIES:
Tetraspora
E2. PSEUDOCILIA ABSENT; COLONIES LACKING DISTINCT MUCILAGE LAYERS; MUCILAGE MAY BE PRESENT, BUT IS NOT VISIBLE UNLESS STAINED
F1. CELLS SPHERICAL WITH LONG, SHARP SPINES; COLONIES USUALLY CONTAIN ONE OR MORE 4-CELL TETRAHEDRAL GROUPS:
Micractinium
F2. CELLS OVAL, FORMING TETRAHEDRAL GROUPS OF 4 IN IRREGULAR (AMORPHOUS) COLONIES:
Stichogloea
F3. CELLS OVAL OR SPHERICAL, GOLDEN BROWN, IN LOOSELY ARRANGED, IRREGULAR (AMORPHOUS) COLONIES; COLONIES ARE ENCLOSED IN MUCILAGE THAT IS NOT VISIBLE UNLESS STAINED:
Gloeobotrys
F4. SPHERICAL OR NEARLY SPHERICAL CELLS WITH DENSE (NOT STAR-SHAPED) CHLOROPLAST; SOLITARY OR IN SMALL TO LARGE SIZED COLONIES; CELLS MAY OR MAY NOT BE SURROUNDED BY MUCILAGE; COLONIES USUALLY SURROUNDED BY DIFFUSE MUCILAGE (RARELY VISIBLE WITHOUT STAINING):
Sphaerocystis
F5. IRREGULAR COLONIES WITH NUMEROUS TINY, SPHERICAL, YELLOWISH GREEN CELLS; RESEMBLES
Chlorella
, BUT DOES NOT CONTAIN STARCH:
Nannochloropsis
E3. PSEUDOCILIA ABSENT; COLONIES SURROUNDED BY DISTINCT MUCILAGE LAYER OR CONNECTED BY MUCILAGE STRANDS; MUCILAGE VISIBLE WITHOUT STAINING
F1. COLONIES CONSISTING OF CLUMPS OF CELLS CONNECTED BY MUCILAGE STRANDS OR RESIDUAL PARENT CELL WALLS
G1. CELLS EMBEDDED IN DENSE MUCILAGE AND NOT VISIBLE OR ONLY PARTLY VISIBLE AT THE APEX; COLONIES ORANGE, GREEN, OR BOTH:
Botryococcus
G2. CELLS IN GROUPS OF 4; CONNECTED TO OTHER GROUPS BY MUCILAGINOUS PARENT CELL WALLS:
Westella
G3. COLONIES WITH GRAPE-LIKE CLUSTERS OF SPHERICAL CELLS CONNECTED TO OTHER CLUSTERS BY THIN MUCILAGE STRANDS:
Botryosphaerella
F2. CELLS WITH GOLDEN BROWN CHLOROPLASTS, ENCLOSED IN HIGHLY BRANCHED MUCILAGE TUBES; CELLS NEARING ZOOSPORE FORMATION WILL BECOME TETHEDRAL AND LOOSELY ARRANGED IN AMORPHOUS COLONIES; SPECIMENS HAVE A STRONG, UNPLEASANT ODOR:
Hydrurus
F3. SPHERICAL OR NEARLY SPHERICAL CELLS WITH DENSE (NOT STAR-SHAPED) CHLOROPLAST; SOLITARY OR IN SMALL TO LARGE SIZED COLONIES; CELLS MAY OR MAY NOT BE SURROUNDED BY MUCILAGE; COLONIES USUALLY SURROUNDED BY DIFFUSE MUCILAGE (RARELY VISIBLE WITHOUT STAINING):
Sphaerocystis
F4. CELLS SURROUNDED BY VERY THICK MUCILAGE THAT IS OFTEN STRIATED; DIFFICULT, INCOMPLETELY DESCRIBED GROUP:
Gloeocystis
and similar
D3. CELLS CLUB-SHAPED, FUSIFORM, CYLINDRICAL, CRESCENT-SHAPED, OR SPINDLE-SHAPED (NOT SPHERICAL OR OVAL)
E1. CELLS CLUB-SHAPED OR CYLINDRICAL; SOLITARY OR IN TREE-LIKE COLONIES WITH CELLS FORMING AT END OF ELONGATED PARENT CELL:
Ophiocytium
E2. COLONY SURROUNDED BY VISIBLE MUCILAGE OR CELLS ATTACHED BY MUCILAGE_STRANDS
F1. COLONIES FORMED FROM 4-CELL GROUPS JOINED BY MUCILAGE STRANDS; EACH 4-CELL GROUP CONTAINS 2 HEART-SHAPED CELLS AND 2 ELLIPTICAL CELLS:
Dimorphococcus
F2. CELLS BROADLY OR NARROWLY FUSIFORM; SOLITARY OR IN LENS-SHAPED COLONIES WITH CELLS OFFSET AND ALIGNED ALONG LONG AXIS; CELLS AND COLONIES ENCLOSED IN LENS-SHAPED MUCILAGE:
Elakatothrix
and
Fusola
F3. CELLS CYLINDRICAL OR FUSIFORM; ALIGNED ALONG LONG AXIS, FORMING BUNDLES ENCLOSED IN DIFFUSE MUCILAGE; COLONIES IRREGULAR BUT MUCILAGE IS OFTEN SPHERICAL OR LENS-SHAPED:
Quadrigula
E3. CELLS AND COLONIES LACKING DISTINCT MUCILAGE; MUCILAGE MAY BE PRESENT IN THESE TAXA, BUT WILL NOT BE DISTINCTLY VISIBLE WITHOUT STAINING
F1. CELLS CLUB-SHAPED OR BROADLY FUSIFORM WITH MANY LONG APICAL BRISTLES AND A SHORT, SPLIT (BIFURCATE) POSTERIOR SPINE; USUALLY IN 2-CELL COLONIES, BUT OCCASIONALLY SOLITARY:
Paradoxia
F2. CELLS NARROWLY FUSIFORM, ALIGNED LENGTHWISE INTO TANGLED LINEAR OR SPHERICAL COLONIES:
Ankistrodesmus
F3. CELLS CYLINDRICAL OR FUSIFORM; COLONIES USUALLY CONTAIN 8 CELLS RADIATING FROM CENTER TO FORM TETRAHEDRAL SHAPE:
Actinastrum
F4. CELLS LONG, CYLINDRICAL, JOINED AT THE ENDS TO FORM NETS COMPRISED OR 5-SIDED OR 6-SIDED SUBUNITS:
Hydrodictyon
F5. CELL BLUNTLY OR ACUTELY CRESCENT-SHAPED
G1. CELLS BROADLY CRESCENT-SHAPED WITH ROUNDED OR BLUNTLY ACUTE APICES; LOOSELY DISTRIBUTED IN COLONY; SURROUNDED BY INDISTINCT MUCILAGE (VISIBLE IF STAINED):
Kirchneriella
G2. CELLS NARROWLY CRESCENT-SHAPED WITH ACUTELY POINTED APEX; GROUPS OF CELLS JOINED ALONG OUTER (DORSAL) EDGE; USUALLY PLANKTONIC:
Messastrum
and
Selenastrum
B3. FILAMENTOUS ALGAE (INCLUDING PSEUDOFILAMENTS)
C1. FILAMENTS OR PSEUDOFILAMENTS ATTACHED TO AQUATIC PLANTS (EPIPHYTIC)
D1. CELLS WITH LONG HAIR-LIKE SETAE
E1. CELLS SPHERICAL WITH SINGLE LONG, SHEATHED HAIR; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS:
Chaetosphaeridium
E2. CELLS HEMISPHERICAL (FLATTENED AGAINST SUBSTRATE), WITH LONG, BRANCHED HAIRS; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS:
Dicranochaete
E3. CELLS RECTANGULAR, BRIGHT GREEN; JOINED INTO LONG FILAMENTS RADIATING FROM CENTRAL POINT TO FORM FLAT, SPHERICAL OR OVAL COLONY:
Coleochaete
E4. CELLS IRREGULARLY CYLINDRICAL WITH ONE OR MORE LONG HAIR-LIKE SETAE; CELLS JOINED TO FORM IRREGULAR CREEPING EPIPHYTIC FILAMENTS:
Aphanochaete
D2. CELLS LACKING OR MOSTLY LACKING LONG HAIR-LIKE SETAE
E1. CELLS SPHERICAL; FORMING LOOSELY ARRANGED PSEUDOFILAMENTS AT THE ENDS OF UPRIGHT, HIGHLY BRANCHED MUCILAGE TUBES:
Mischococcus
E2. CELLS CLUB-SHAPED OR ELLIPTICAL, GOLDEN BROWN; FILAMENTS UPRIGHT AND HIGHLY BRANCHED:
Phaeothamnion
E3. CELLS RECTANGULAR, GOLDEN BROWN; FORMING IRREGULAR, RECTANGULAR COLONIES OR SHORT FILAMENTS; EPIPHYTIC ON FILAMENTOUS ALGAE:
Phaeoplaca
E4. CELLS RECTANGULAR, BRIGHT GREEN; JOINED INTO LONG FILAMENTS RADIATING FROM CENTRAL POINT TO FORM FLAT, SPHERICAL OR OVAL COLONY:
Coleochaete
C2. CELLS FORM PSEUDOFILAMENTS WHERE THEY ARE ALIGNED END-TO-END BUT NOT JOINED ACROSS THE ENDWALL
D1. PSEUDOFILAMENTS ARE ENCLOSED IN A VISIBLE MUCILAGE LAYER OR CELLS ARE FORMED AT THE END OF MUCILAGE TUBES
E1. PSEUDOFILAMENTS MOSTLY UNBRANCHED
F1. CELLS CYLINDRICAL WITH ROUNDED ENDS OR OVAL (L&>;W)
G1. PSEUDOFILAMENTS SHORT (≤10 CELLS); CELLS LONG, CYLINDRICAL, BROADLY ROUNDED; PSEUDOFILAMENTS SURROUNDED BY VERY WIDE, INCONSPICUOUS MUCILAGE LAYER:
Gloeotila
cf.
G2. PSEUDOFILAMENTS USUALLY LONGER THAN 10 CELLS; CELLS SHORT, CYLINDRICAL, BROADLY ROUNDED, OFTEN FORMING PAIRS; PSEUDOFILAMENTS SURROUNDED BY DISTINCT MUCILAGE LAYER:
Gloeotila
cf.
F2. CELLS SPHERICAL OR LENS-SHAPED
G1. CELLS WITH GOLDEN BROWN CHLOROPLASTS, ENCLOSED IN HIGHLY BRANCHED (OCCASIONALLY UNBRANCHED) MUCILAGE TUBES; CELLS NEARING ZOOSPORE FORMATION WILL BECOME TETHEDRAL AND LOOSELY ARRANGED IN AMORPHOUS COLONIES; SPECIMENS HAVE A STRONG, UNPLEASANT ODOR:
Hydrurus
G2. CELLS BRIGHT GREEN, SPHERICAL; FORMING UNBRANCHED OR VERY SPARSELY BRANCHED PSEUDOFILAMENTS ENCLOSED IN MUCILAGE TUBE; UNISERIATE (ONE CELL WIDE) OR MULTISERIATE:
Palmodictyon
G3. CELLS BRIGHT GREEN, SPHERICAL, WITH TRANSVERSE RING; FORMING UNISERIATE FILAMENTS (ONE CELL WIDE); FILAMENTS ARE SURROUNDED BY MUCILAGE THAT IS RARELY VISIBLE WITHOUT STAINING:
Radiofilum
G4. CELLS BRIGHT GREEN, SPHERICAL, WITH TRANSVERSE RING; FORMING UNBRANCHED, UNISERIATE OR MULTISERIATE FILAMENTS OR PSEUDOFILAMENTS:
Flintia
E2. PSEUDOFILAMENTS SPARSELY OR DENSELY BRANCHED
F1. CELLS SPHERICAL; FORMING LOOSELY ARRANGED PSEUDOFILAMENTS AT THE ENDS OF UPRIGHT, HIGHLY BRANCHED MUCILAGE TUBES:
Mischococcus
F2. Algae/A2.Nonmotile_Algae/B3.filament_pseudofilament/C2.pseudofilaments/D1.filaments_with_mucilage/E2.branched/F2.cells_inside_mucilage_golden_HYDRURUS
F3. CELLS BRIGHT GREEN, SPHERICAL; FORMING UNBRANCHED OR VERY SPARSELY BRANCHED PSEUDOFILAMENTS ENCLOSED IN MUCILAGE TUBE; UNISERIATE (ONE CELL WIDE) OR MULTISERIATE:
Palmodictyon
D2. PSEUDOFILAMENTS ARE NOT ENCLOSED IN DISTINCT MUCILAGE
E1. PSEUDOFILAMENTS SHORT (≤10 CELLS); CELLS SPHERICAL, WITH GOLDEN BROWN CHLOROPLASTS; CELLS OFTEN WITH RADIATING RHIZOPODIA:
Chrysidiastrum
E2. PSEUDOFILAMENTS SHORT (≤10 CELLS); CELLS LONG, CYLINDRICAL, BROADLY ROUNDED; PSEUDOFILAMENTS SURROUNDED BY VERY WIDE, INCONSPICUOUS MUCILAGE LAYER:
Gloeotila
cf.
E3. CELLS BRIGHT GREEN, SPHERICAL, WITH TRANSVERSE RING; FORMING UNISERIATE FILAMENTS (ONE CELL WIDE); FILAMENTS ARE SURROUNDED BY MUCILAGE THAT IS RARELY VISIBLE WITHOUT STAINING:
Radiofilum
C3. UNBRANCHED FILAMENTOUS ALGAE
D1. CELLS LENS-SHAPED AND COMPRESSED (L&<;W) WITH TRANSVERSE RING
E1. CELLS BRIGHT GREEN, SPHERICAL, WITH TRANSVERSE RING; FORMING UNISERIATE FILAMENTS (ONE CELL WIDE):
Radiofilum
E2. CELLS BRIGHT GREEN, SPHERICAL, WITH TRANSVERSE RING; FORMING UNBRANCHED, UNISERIATE OR MULTISERIATE FILAMENTS OR PSEUDOFILAMENTS:
Flintia
D2. CELLS CYLINDRICAL, MOSTLY LONGER THAN WIDE, WITH RIBBON-LIKE, BAND-LIKE, OR STAR-SHAPED CHLOROPLASTS
E1. CELLS WITH SINGLE FLAT CHLOROPLAST EXTENDING DOWN THE CENTER OF THE CELL (AXIAL); CHLOROPLAST OFTEN TWISTED; VERY COMMON, DIVERSE GENUS:
Mougeotia
E2. CELLS WITH ONE OR MORE NARROW, RIBBON-LIKE CHLOROPLAST(S) SPIRALLING AROUND THE INSIDE OF THE CELL (PARIETAL); VERY COMMON, DIVERSE GENUS:
Spirogyra
E3. CELLS WITH ONE NARROW, RIBBON-LIKE CHLOROPLAST THAT FORMS AN PARTIAL OR COMPLETE RING CIRCLING THE CENTER OF THE CELL (PARIETAL); ZOOSPORES OFTEN FORM QUICKLY IN SAMPLES WAITING TO BE EXAMINED:
Ulothrix
and
Uronema
E4. CELLS WITH TWO STAR-SHAPED CHLOROPLASTS LOCATED NEAR THE CENTER OF THE CELL (AXIAL); VERY COMMON, DIVERSE GENUS:
Zygnema
D3. CELLS VARIOUS SHAPES, INCLUDING CYLINDRICAL, BUT LACKING TRANSVERSE RINGS; CHLOROPLASTS NOT RIBBON-LIKE, BAND-LIKE, OR STAR-SHAPED; DIFFICULT GROUP WITH FEW OVERLAPPING FEATURES
E1. CELLS WITH H-SHAPED ENDWALL EXTENSIONS
F1. CELLS CYLINDRICAL; CHLOROPLASTS RETICULATED (BEAD-LIKE) AND BRIGHT OR DULL GREEN (WILL STAIN FOR STARCH IN LUGOLS); ENDWALL EXTENSIONS ROBUST, VISIBLE AT ENDS OF FILAMENTS:
Microspora
F2. CELLS CYLINDRICAL; CHLOROPLASTS GREEN (WILL STAIN FOR STARCH IN LUGOLS), SADDLE-LIKE, EXTENDING ABOUT HALF WAY AROUND CELL (PARIETAL); ENDWALL EXTENSIONS VERY SHORT, ONLY VISIBLE AT ENDS OF FILAMENTS:
Klebsormidium
Tribonema also resembles
Bumillaria
(Ochrophyta), which usually have short cells and easily fragmented filaments'> F3. CELLS LONG AND CYLINDRICAL; CHLOROPLASTS YELLOWISH GREEN (WILL NOT STAIN FOR STARCH IN LUGOL'S), DISK-SHAPED; ENDWALL EXTENSIONS LONG, NEEDLE-LIKE, FRAGILE, RARELY VISIBLE EXCEPT AT END OF FILAMENT:
Tribonema
Bumillaria (Ochrophyta) can be distinguished by its shorter cells and easily fragmented filaments'> F4. CELLS SHORT AND CYLINDRICAL; CHLOROPLASTS YELLOWISH GREEN (WILL NOT STAIN FOR STARCH IN LUGOL'S), DISK-SHAPED; ENDWALL EXTENSIONS SHORT (COMPARED TO
Tribonema
), ROBUST, FORMING PERSISTENT H-SHAPED SEGMENTS IN DECOMPOSING SAMPLES; FILAMENTS EASILY FRAGMENTED:
Bumilleria
E2. CELLS CYLINDRICAL OR OVAL, OFTEN PAIRED; CELL WALL BECOMING INCREASINGLY THICK AND STRIATED, ESPECIALLY AT THE CROSSWALLS:
Binuclearia
E3. CELLS CYLINDRICAL (L&>;W); SOME CELLS WITH RING-LIKE CELL DIVISION SCARS THAT RESEMBLE PIPE THREADS; CHLOROPLASTS RETICULATED (NET-LIKE, PARIETAL); OFTEN WITH WITH INFLATED OOGONIA; MAY BE ATTACHED TO SUBSTRATE BY ENLARGED HOLDFAST CELL:
Oedogonium
E4. CELLS VARIOUS SHAPES; ENDWALLS NOT THICKENED OR WITH H-SHAPED EXTENSIONS OR RING-LIKE DIVISION SCARS; SOME GENERA MAY BE SPARSELY BRANCHED
F1. CELLS LONG AND CYLINDRICAL; FILAMENTS COARSE, FORMING DENSE MATS ON SUBMERGED SURFACES (NOT PLANKTONIC), LACKING DISTINCT MUCILAGE, BUT OFTEN COVERED WITH EPIPHYTES; FILAMENTS UNBRANCHED OR VARY SPARSELY BRANCHED
G1. FILAMENTS LACKING CROSSWALLS EXCEPT BELOW REPRODUCTIVE STRUCTURES; MOSTLY UNBRANCHED EXCEPT FOR SHORT REPRODUCTIVE FILAMENTS; CHLOROPLASTS NUMEROUS, TINY, DISK-LIKE, YELLOWISH GREEN; FILAMENTS OFTEN CONTAIN LARGE, SINGLE OR PAIRED OOGONIA:
Vaucheria
G2. FILAMENTS WITH DISTINCT CROSSWALLS, UNBRANCHED OR SPARSELY BRANCHED; CELLS LONG, CYLINDRICAL; CHLOROPLASTS DENSE AND RETICULATED (NET-LIKE); STARCH PRESENT (TEST USING LUGOL'S):
Cladophora
G3. FILAMENTS WITH DISTINCT CROSSWALLS, UNBRANCHED OR SPARSELY BRANCHED; CELLS LONG, CLYINDRICAL; CHLOROPLASTS RETICULATED (NET-LIKE); STARCH PRESENT (TEST USING LUGOL'S); DARK AKINETES OFTEN FORMED AT ENDS AND WITHIN FILAMENT:
Pithophora
F2. CELLS CYLINDRICAL, SLIGHTLY LONGER THAN WIDE, SOMETIMES PAIRED; CHLOROPLAST STELLATE WITH CENTRAL PYRENOID; YOUNG FILAMENTS SURROUNDED BY THIN, STRIATED MUCILAGE THAT BECOMES INFLATED AND INCREASINGLY STRIATED WITH AGE:
Cylindrocapsa
F3. CELLS OVAL, ELLIPTICAL, OR CYLINDRICAL; OFTEN PAIRED; CHLOROPLAST PLATE-LIKE OR GIRDLE-SHAPED (NOT STELLATE), USUALLY WITH CENTRAL PYRENOID; FILAMENTS SURROUNDED BY WIDE, DIFFUSE MUCILAGE:
Geminella
C4. BRANCHED FILAMENTOUS ALGAE
D1. FILAMENTS WITH DISTINCTLY LARGER PRIMARY BRANCHES AND SMALLER SECONDARY BRANCHES; CELLS IN SECONDARY BRANCHES MAY EXTEND TO FORM LONG, HAIR-LIKE SETAE
E1. FILAMENTS WITH HIGHLY DIFFERENTIATED MAIN AND SECONDARY BRANCHES; MAIN BRANCH MULTICELLULAR WITH LONG CYLINDRICAL CELLS; SECONDARY BRANCHES WITH TEARDROP-SHAPED, OVAL, OR ELLIPTICAL CELLS FORMING DENSE WHORLS:
Batrachospermum
and
Paludicola
E2. FILAMENTS WITH HIGHLY DIFFERENCIATED MAIN AND SECONDARY BRANCHES; CELLS IN MAIN BRANCH SHORT, WIDE, BARREL-SHAPED, WITH FRINGED, RING-LIKE (PARIETAL) CHLOROPLAST; CELLS IN SIDE BRANCHES MUCH SMALLER, CYLINDRICAL OR STRONGLY TAPERED, WITH NET-LIKE (RETICULATE) CHLOROPLASTS:
Draparnaldia
D2. FILAMENTS WITH APPROXIMATELY SIMILAR CELLS FORMING PRIMARY AND SECONDARY BRANCHES; FILAMENTS MAY HAVE DISSIMILAR TERMINAL CELLS AND
SLIGHTLY
LARGER CELLS IN THE MAIN BRANCH
E1. CELLS PINKISH PURPLE; VEGETATIVE CELLS IN SECONDARY BRANCHES OFTEN FORM LONG, HAIR-LIKE SETAE; CLUMPED SPORE-FORMING BRANCHES OFTEN PRESENT:
Audouinella
E2. CELLS LONG, CYLINDRICAL, JOINED AT THE ENDS TO FORM NETS COMPRISED OR 5-SIDED OR 6-SIDED SUBUNITS:
Hydrodictyon
E3. CELLS CLUB-SHAPED OR CYLINDRICAL; SOLITARY OR IN TREE-LIKE COLONIES WITH CELLS FORMING AT END OF ELONGATED PARENT CELL:
Ophiocytium
E4. FILAMENTS WITH CELLS EXTENDED INTO LONG, HAIR-LIKE SETAE
F1. CELLS WITH VERY LONG HAIR-LIKE SETAE WITH AN EXPANDED (BULBOUS) BASE; MAY HAVE SPECIALIZED HOLDFAST AT THE BASE OF THE FILAMENT:
Bulbochaete
F2. FILAMENTS MOSTLY ATTACHED TO SUBMERGED VEGETATION, FORMING LARGE, DENSE, HEMISPHERICAL OR SHRUBBY CLUMPS; TERMINAL CELLS ON SECONDARY BRANCHES ACUTELY POINTED, USUALLY WITH A FEW CELLS EXTENDED INTO LONG, HAIR-LIKE SETAE:
Chaetophora
and
Chaetophoropsis
F3. FILAMENTS MOSTLY ATTACHED TO SUBMERGED VEGETATION, FORMING DIFFUSE, IRREGULARLY SHAPED CLUMPS; OFTEN HAS RHIZOIDAL BASAL CELLS; TERMINAL CELLS ACUTELY POINTED OR EXTENDED INTO LONG, HAIR-LIKE SETAE:
Stigeoclonium
E5. FILAMENTS LACKING (OR MOSTLY LACKING) CELLS THAT FORM LONG, HAIR-LIKE SETAE
F1. FILAMENTS COARSE, SPARSELY BRANCHED, OFTEN FORMING DENSE MATS ON SUBMERGED OR DAMP SURFACES; CELLS MOSTLY CYLINCRICAL
G1. FILAMENTS LACKING CROSSWALLS EXCEPT BELOW REPRODUCTIVE STRUCTURES; MOSTLY UNBRANCHED EXCEPT FOR SHORT REPRODUCTIVE FILAMENTS; CHLOROPLASTS NUMEROUS, TINY, DISK-LIKE, YELLOWISH GREEN; FILAMENTS OFTEN CONTAIN LARGE, SINGLE OR PAIRED OOGONIA:
Vaucheria
G2. FILAMENTS WITH DISTINCT CROSSWALLS, UNBRANCHED OR SPARSELY BRANCHED; CELLS LONG, CYLINDRICAL; CHLOROPLASTS DENSE AND RETICULATED (NET-LIKE); STARCH PRESENT (TEST USING LUGOL'S):
Cladophora
G3. FILAMENTS WITH DISTINCT CROSSWALLS, UNBRANCHED OR SPARSELY BRANCHED; CELLS LONG, CLYINDRICAL; CHLOROPLASTS RETICULATED (NET-LIKE); STARCH PRESENT (TEST USING LUGOL'S); DARK AKINETES OFTEN FORMED AT ENDS AND WITHIN FILAMENT:
Pithophora
G4. FILAMENTS BRIGHT ORANGE; CELLS CONTAIN ORANGE CAROTENOIDS THAT MAY OBSCURE THE GREEN CHLOROPLAST:
Trentepohlia
F2. CELLS SPHERICAL, OVAL, TEARDROP-SHAPED, OR ELLIPTICAL; CHLOROPLASTS GOLDEN BROWN; FILAMENTS MOSTLY WITH IRREGULAR OR HIGHLY BRANCHED STRUCTURE
G1. CELLS CLUB-SHAPED OR ELLIPTICAL, GOLDEN BROWN; FILAMENTS UPRIGHT AND HIGHLY BRANCHED:
Phaeothamnion
G2. CELLS WITH GOLDEN BROWN CHLOROPLASTS, ENCLOSED IN HIGHLY BRANCHED FILAMENTOUS OR PSEUDOFILAMENTOUS MUCILAGE TUBES; CELLS NEARING ZOOSPORE FORMATION WILL BECOME TETHEDRAL AND LOOSELY ARRANGED IN AMORPHOUS COLONIES; SPECIMENS HAVE A STRONG, UNPLEASANT ODOR:
Hydrurus
G3. CELLS SPHERICAL; FORMING LOOSELY ARRANGED PSEUDOFILAMENTS OR FILAMENTS AT THE ENDS OF UPRIGHT, HIGHLY BRANCHED MUCILAGE TUBES:
Mischococcus
F3. CELLS LONG, CYLINDRICAL, BRIGHT OR DULL GREEN (STARCH PRESENT); FILAMENTS DENSELY BRANCHED
G1. CELLS NARROWLY CYLINDRICAL; FILAMENTS HIGHLY BRANCHED, OPEN, WIDELY SPREADING:
Microthamnion
G2. FILAMENTS MOSTLY ATTACHED TO SUBMERGED VEGETATION, FORMING LARGE, DENSE, HEMISPHERICAL OR SHRUBBY CLUMPS; TERMINAL CELLS ON SECONDARY BRANCHES ACUTELY POINTED, USUALLY WITH A FEW CELLS EXTENDED INTO LONG, HAIR-LIKE SETAE:
Chaetophora
and
Chaetophoropsis
G3. FILAMENTS MOSTLY ATTACHED TO SUBMERGED VEGETATION, FORMING DIFFUSE, IRREGULARLY SHAPED CLUMPS; OFTEN HAS RHIZOIDAL BASAL CELLS; TERMINAL CELLS ACUTELY POINTED OR EXTENDED INTO LONG, HAIR-LIKE SETAE:
Stigeoclonium
B4. CELLS ATTACHED TO ZOOPLANKTON (EPIZOIC), LIVING INSIDE ZOOPLANKTON OR OTHER AQUATIC ANIMALS (ENDOZOIC), OR ATTACHED TO AQUATIC PLANTS (EPIPHYTIC)
C1. CELLS ATTACHED TO ZOOPLANKTON (EPIZOIC) OR LIVING INSIDE ZOOPLANKTON OR OTHER AQUATIC ANIMALS (ENDOZOIC)
D1. CELLS CRESCENT-SHAPED (GENTLY CURVED) WITH STOUT APICAL AND POSTERIOR SPINES; USUALLY EPIZOIC, OFTEN ON
DAPHNIA
:
Korshikoviella
D2. CELLS RESEMBLE
EUGLENA
BUT ARE USUALLY EPIZOIC ON FRESHWATER MICROCRUSTACEANS:
Colacium
D3. CHLORELLA-LIKE CELLS LIVING INSIDE ZOOPLANKTON AND OTHER AQUATIC ANIMALS (ENDOZOIC):
Zoochlorella group
C2. CELLS SOLITARY, ATTACHED TO AQUATIC PLANTS (EPIPHYTIC)
D1. PROTOPLAST (LIVING PORTION OF CELL) ENCLOSED IN RIGID LORICA
E1. LORICA ATTACHED BY THIN BAND THAT ENCIRCLES PLANT SUBSTRATE:
Chyrsopyxis
E2. LORICA ATTACHED BY LONG STIPE:
Stylochrysalis
E3. LORICA ATTACHED BY SHORT OR LONG STIPE:
Derepyxis
E4. LORICA SESSILE; CELLS FLASK-SHAPED, USUALLY ORANGE OR BROWN:
Lagynion
E5. LORICA SESSILE OR ATTACHED BY SHORT STIPE; CELLS TRUMPET-SHAPED OR CYLINDRICAL:
Epipyxis
D2. CELLS NOT ENCLOSED IN RIGID LORICA; CELL WALL MAY BE RIGID OR FLEXIBLE
E1. CELLS SESSILE ON PLANT SUBSTRATE (NO ATTACHMENT STYPE)
F1. CELLS OVAL OR ELLIPTICAL AND BRIGHT BLUE-GREEN; SOLITARY OR IN SMALL COLONIES ENCLOSED IN OLD PARENT CELL WALL; OFTEN EPIPHYTIC:
Glaucocystis
F2. CELLS SPHERICAL WITH SINGLE LONG, SHEATHED HAIR; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS:
Chaetosphaeridium
F3. CELLS HEMISPHERICAL (FLATTENED AGAINST SUBSTRATE), WITH LONG, BRANCHED HAIRS; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS:
Dicranochaete
F4. CELLS FUSIFORM, OVAL, ELLIPTICAL, OR CRESCENT-SHAPED; CELLS SESSILE OR ATTACHED BY LONG OR SHORT STIPE:
Characium
,
Characiopsis
,
Pseudocharacium
, and similar
E2. CELLS ON STIPES (NOT SESSILE)
F1. CELLS OVAL, SOLITARY, WITH LARGE PYRENOID; ATTACHED TO SUBSTRATE BY SHORT STIPE; USUALLY EPIPHYTIC ON
Woronichinia
:
Stylosphaeridium
F2. CELLS BROADLY CRESCENT-SHAPED, GOLDEN BROWN, WITH RED PIGMENT SPOT; OFTEN EPIPHYTIC:
Cystodinium
F3. CELLS CLUB-SHAPED OR CYLINDRICAL; SOLITARY OR IN TREE-LIKE COLONIES WITH CELLS FORMING AT END OF ELONGATED PARENT CELL:
Ophiocytium
F4. CELLS FUSIFORM, OVAL, ELLIPTICAL, OR CRESCENT-SHAPED; CELLS SESSILE OR ATTACHED BY LONG OR SHORT STIPE:
Characium
,
Characiopsis
,
Pseudocharacium
, and similar
C3. CELLS FORMING COLONIES; ATTACHED TO PLANTS (EPIPHYTIC)
D1. COLONIES PARASITIC ON TREE POLLEN; CELLS PYRAMIDAL, WITH A SHORT APICAL SPINE, OFTEN LACKING CHLOROPHYLL; CELLS JOINED BY SHORT EXTENSIONS TO FORM OPEN, SPHERICAL COLONY:
Ducellieria
D2. CELLS WITH LONG HAIR-LIKE SETAE OR PSEUDOCILIA; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS; HIGHLY VARIABLE APPEARANCE
E1. CELLS RECTANGULAR, BRIGHT GREEN; JOINED INTO LONG FILAMENTS RADIATING FROM CENTRAL POINT TO FORM FLAT, SPHERICAL OR OVAL COLONY:
Coleochaete
E2. CELLS SPHERICAL, WITH LONG, FLEXIBLE PSEUDOCILIA; LOOSELY ENCLOSED IN A CLUB-SHAPED COLONIAL MUCILAGE; EPIPHYTIC ON AQUATIC MACROPHYTES AND FILAMENTOUS ALGAE:
Apiocystis
E3. CELLS SPHERICAL WITH SINGLE LONG, SHEATHED HAIR; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS:
Chaetosphaeridium
E4. CELLS HEMISPHERICAL (FLATTENED AGAINST SUBSTRATE), WITH LONG, BRANCHED HAIRS; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS:
Dicranochaete
D3. CELLS LACKING OR MOSTLY LACKING LONG HAIR-LIKE SETAE
E1. CELLS RECTANGULAR, GOLDEN BROWN; FORMING IRREGULAR, RECTANGULAR COLONIES OR SHORT FILAMENTS; EPIPHYTIC ON FILAMENTOUS ALGAE:
Phaeoplaca
E2. CELLS RECTANGULAR, BRIGHT GREEN; JOINED INTO LONG FILAMENTS RADIATING FROM CENTRAL POINT TO FORM FLAT, SPHERICAL OR OVAL COLONY:
Coleochaete
E3. CELLS CLUB-SHAPED OR CYLINDRICAL; SOLITARY OR IN TREE-LIKE COLONIES WITH CELLS FORMING AT END OF ELONGATED PARENT CELL:
Ophiocytium
E4. CELLS OVAL OR ELLIPTICAL AND BRIGHT BLUE-GREEN; SOLITARY OR IN SMALL COLONIES ENCLOSED IN OLD PARENT CELL WALL; OFTEN EPIPHYTIC:
Glaucocystis
E5. LORICA SESSILE OR ATTACHED BY SHORT STIPE; CELLS TRUMPET-SHAPED OR CYLINDRICAL:
Epipyxis
C4. CELLS JOINED OR POSITIONED END-TO-END IN FILAMENTS OR PSEUDOFILAMENTS; FILAMENTS ATTACHED TO AQUATIC PLANTS (EPIPHYTIC)
D1. CELLS WITH LONG HAIR-LIKE SETAE
E1. CELLS SPHERICAL WITH SINGLE LONG, SHEATHED HAIR; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS:
Chaetosphaeridium
E2. CELLS HEMISPHERICAL (FLATTENED AGAINST SUBSTRATE), WITH LONG, BRANCHED HAIRS; SOLITARY OR IN IRREGULAR COLONIES OR FILAMENTS:
Dicranochaete
E3. CELLS RECTANGULAR, BRIGHT GREEN; JOINED INTO LONG FILAMENTS RADIATING FROM CENTRAL POINT TO FORM FLAT, SPHERICAL OR OVAL COLONY:
Coleochaete
E4. CELLS IRREGULARLY CYLINDRICAL WITH ONE OR MORE LONG HAIR-LIKE SETAE; CELLS JOINED TO FORM IRREGULAR CREEPING EPIPHYTIC FILAMENTS:
Aphanochaete
D2. CELLS LACKING OR MOSTLY LACKING LONG HAIR-LIKE SETAE
E1. CELLS SPHERICAL; FORMING LOOSELY ARRANGED PSEUDOFILAMENTS AT THE ENDS OF UPRIGHT, HIGHLY BRANCHED MUCILAGE TUBES:
Mischococcus
E2. CELLS CLUB-SHAPED OR ELLIPTICAL, GOLDEN BROWN; FILAMENTS UPRIGHT AND HIGHLY BRANCHED:
Phaeothamnion
E3. CELLS RECTANGULAR, GOLDEN BROWN; FORMING IRREGULAR, RECTANGULAR COLONIES OR SHORT FILAMENTS; EPIPHYTIC ON FILAMENTOUS ALGAE:
Phaeoplaca
E4. CELLS RECTANGULAR, BRIGHT GREEN; JOINED INTO LONG FILAMENTS RADIATING FROM CENTRAL POINT TO FORM FLAT, SPHERICAL OR OVAL COLONY:
Coleochaete
A3. MOTILE ALGAE WITH CHLOROPLASTS AND FLAGELLA
B1. MOTILE COLONIES WITH TWO OR MORE CELLS
C1. CELLS WITH TWO EQUAL FLAGELLA
D1. FLAT COLONIES WITH 4-16 SPHERICAL OR OVAL CELLS:
Gonium
and
Tetrabaena
D2. SPHERICAL, OVAL, OR ELLIPTICAL COLONIES (NOT FLAT)
E1. SPHERICAL COLONIES WITH 16-32 COMPRESSED, WEDGE-SHAPED CELLS:
Pandorina
E2. SPHERICAL COLONIES WITH 16-32 WELL-SEPARATED SPHERICAL CELLS:
Eudorina
E3. LARGE COLONIES WITH MORE THAN 250 TINY CELLS:
Volvox
E4. LARGE COLONIES WITH 32-128 CELLS; LARGE AND SMALL CELLS ON OPPOSITE HEMISPHERES:
Pleodorina
C2. CELLS WITH TWO DISSIMILAR FLAGELLA
D1. CELLS COVERED WITH SMALL SCALES (SCALED CHRYSOPHYTES); MAY ALSO HAVE SHORT OR LONG SPINES
E1. CELLS COVERED WITH TINY SCALES AND STOUT SPINES:
Chrysosphaerella
E2. CELLS COVERED WITH TINY, ORNATE SCALES (NO LONG SPINES):
Synura
D2. CELLS NOT COVERED WITH SCALES OR SPINES
E1. CELLS SMOOTH (NOT SPINY); ENCLOSED IN VASE-LIKE LORICA, FORMING TREE-LIKE COLONIES:
Dinobryon
E2. CELLS SMOOTH (NOT SPINY); COLONIES SPHERICAL, SURROUNDED BY MUCILAGE CONTAINING TINY SCALES EXCRETED BY CELLS:
Neotessella
E3. CELLS SMOOTH (NOT SPINY); COLONIES CONTAIN OVAL OR TEARDROP-SHAPED CELLS JOINED BY LONG, FRAGILE MUCILAGE THREADS:
Uroglena
and
Uroglenopsis
B2. MOTILE SINGLE-CELL ALGAE
C1. CELLS WITH ONE VISIBLE FLAGELLUM
D1. CELLS COVERED WITH SCALES (SCALED CHRYSOPHYTES); MOST SPECIES ALSO HAVE LONG SPINES:
Mallomonas
D2. CELLS ENCLOSED IN A RIGID LORICA
E1. LORICA SPHERICAL, OVAL, OR ELLIPTICAL; REDDISH BROWN OR DARK BROWN; SURFACE SMOOTH, GRANULAR, SPINY, WARTY, OR RIDGED:
Trachelomonas
E2. LORICA VASE-SHAPED WITH TAPERED NECK AND POINTED CAUDAL TAIL; TRANSPARENT OR YELLOWISH BROWN; SURFACE SMOOTH, WRINKLED, OR GRANULAR (NOT SPINY):
Strombomonas
E3. CELLS TINY; LORICA BOWL-SHAPED, TRANSPARENT, WITH SPIRALLING RIDGES:
Kephyrion
and
Pseudokephyrion
D3. CELLS NOT COVERED WITH SCALES OR ENCLOSED IN A LORICA; MAY BE RIGID OR FLEXIBLE
E1. CELL WALL RIGID
G1. CELLS RIGID AND FLATTENED, USUALLY WITH LONG POSTERIOR TAIL (CAUDUS):
Phacus
G2. CELLS OVAL WITH DEEP CENTRAL GROOVE (COFFEE-BEAN SHAPE):
Cryptoglena
G3. CELLS OVAL, ELLIPTICAL, OR FUSIFORM, WITH RIGID WALLS (LARGE, DIVERSE GROUP):
Lepocinclis
,
Monomorphina
, and
Euglena
(in part)
E2. CELL WALL FLEXIBLE; CELLS EXHIBIT WORM-LIKE OR AMOEBOID MOVEMENT IN ADDITION TO FLAGELLAR MOVEMENT
G1. CELLS ELLIPTICAL, CYLINDRICAL, OR TEARDROP-SHAPED; CELLS USUALLY WITH WORM-LIKE EUGLENOID MOVEMENT:
Euglena
and
Euglenaformis
G2. CELLS RESEMBLE
EUGLENA
BUT ARE USUALLY EPIZOIC ON FRESHWATER MICROCRUSTACEANS:
Colacium
G3. CELLS SPHERICAL, GOLDEN BROWN, OFTEN WITH WARTY SURFACE:
Chromulina
G4. CELLS WITH FLEXIBLE WALLS AND LONG, THIN PSEUDOPODS; CELLS MAY EXHIBIT AMOEBOID MOVEMENT:
Chrysamoeba
and
Rhizochrysis
C2. CELLS WITH TWO EQUAL LENGTH FLAGELLA
D1. CELLS ENCLOSED IN FIRM, TRANSPARANT, SPHERICAL MUCILAGE LAYER
E1. CELLS WITH BRIGHT RED OR PARTLY RED PROTOPLASTS SURROUNDED BY SPHERICAL MUCILAGE:
Haematococcus
E2. CELLS WITH GREEN PROTOPLASTS (NOT RED) SURROUNDED BY SPHERICAL OR OVAL MUCILAGE:
Vitreochlamys
D2. CELLS ENCLOSED IN RIGID LORICA
E1. CELLS ENCLOSED IN A ROUGH, REDDISH BROWN LORICA; LORICA SEPARATES ALONG TRANSVERSE (EQUATORIAL) GROOVE:
Hemitoma
E2. CELLS CIRCULAR IN FACE VIEW; LENS-SHAPED IN SIDE VIEW; ENCLOSED IN TRANSPARENT OR YELLOWISH, GRANULAR LORICA; LORICA SEPARATED ALONG LONGITUDINAL GROOVE:
Phacotus
D3. CELLS NOT ENCLOSED IN LORICA OR SURROUNDED BY SPHERICAL OR OVAL MUCILAGE
E1. NARROWLY ELLIPTICAL OR SPINDLE-SHAPED CELLS; FLAGELLA OFTEN DIRECTED BACKWARDS; CELLS OFTEN NONMOTILE AND EMBEDDED IN MUCILAGE OF OTHER ALGAE:
Chlorogonium
E2. CELLS SLIPPER-SHAPED, OVAL, TEARDROP-SHAPED; ASYMMETRIC; TWO NEARLY EQUAL FLAGELLA INSERTED BELOW APEX (SUBAPICAL):
Cryptomonads
E3. SPHERICAL, OVAL, OR ELLIPTICAL CELLS WITH TWO EQUAL FLAGELLA INSERTED AT THE APEX (LARGE, DIFFICULT GROUP):
Chlamydomonas
and similar
C3. CELLS WITH TWO DISSIMILAR FLAGELLA
D1. CELLS WITH ONE FORWARD AND ONE TRAILING FLAGELLUM
E1. CELLS TEARDROP-SHAPED OR OVAL; CELL WALL CONTAINS MANY SCATTERED TRICHOCYSTS:
Gonyostomum
E2. CELLS OVAL OR SPHERICAL; CELL WALL CONTAINS KNOBBY MUCILAGE GRANULES (NO TRICHOCYSTS):
Vacuolaria
D2. CELLS WITH ONE TRANSVERSE AND ONE TRAILING FLAGELLUM (Dinoflagellates)
E1. CELLS WITH FLEXIBLE WALLS DIVIDED BY CINGULUM INTO EPICONE AND HYPOCONE (DIFFICULT, INCOMPLETELY DESCRIBED GROUP):
athecate dinoflatellates
(
Amphidinium
, Gymnodinium,
Hemidinium
, and others)
E2. CELLS WITH RIGID, PLATE-LIKE WALLS DIVIDED BY CINGULUM INTO EPITHECA AND HYPOTHECA (DIFFICULT, INCOMPLETELY DESCRIBED GROUP:
thecate dinoflatellates
(
Ceratium
, Peridinium, and others)
D3. CELLS WITH TWO FORWARD-DIRECTED APICAL OR SUBAPICAL FLAGELLA
E1. CELLS TINY; LORICA BOWL-SHAPED, TRANSPARENT, WITH SPIRALLING RIDGES:
Kephyrion
and
Pseudokephyrion
E2. CELLS SMOOTH (NOT SPINY); SOLITARY OR IN COLONIES OF OVAL OR TEARDROP-SHAPED CELLS JOINED BY LONG, FRAGILE MUCILAGE THREADS:
Uroglena
and
Uroglenopsis
E3. CELLS TEARDROP-SHAPED OR SPHERICAL; MAY HAVE WARTY SURFACE:
Ochromonas
E4. CELLS SLIPPER-SHAPED, OVAL, TEARDROP-SHAPED; ASYMMETRIC; TWO NEARLY EQUAL FLAGELLA INSERTED BELOW APEX (SUBAPICAL):
Cryptomonads
E5. CELLS OVAL OR SPHERICAL; CELL WALL CONTAINS KNOBBY MUCILAGE GRANULES (NO TRICHOCYSTS):
Vacuolaria
C4. CELLS WITH MORE THAN TWO FLAGELLA
D1. CELLS SPHERICAL OR OVAL WITH WHAT APPEARS TO BE 3 FLAGELLA (2 FLAGELLA AND A HAPTONEMA):
Chrysochromulina/Prymnesium
D2. CELLS SPHERICAL, OVAL, OR ELLIPTICAL, WITH 4 EQUAL FLAGELLA:
Carteria
D3. CELLS HEART-SHAPED AND FLATTENED, WITH 4 EQUAL FLAGELLA:
Tetraselmis
A4. CELLS DIVIDED INTO MIRROR-IMAGE SEMI-CELLS:
Desmids
(see key at
cedar.wwu.edu/cedarbooks/14/
)
B1. Desmids are common in a wide variety of freshwater habitats. Click here to see examples of desmids from Northwest Washington
A5. CELLS ENCLOSED IN GLASSY, ORNAMENTAL FRUSTULES:
Diatoms
(see key at
diatoms.org)
B1. Diatoms are common in almost all freshwater habitats. Click here to see examples of freshwater diatoms from Northwest Washington