A2. NONMOTILE ALGAE WITH CHLOROPLASTS

B1. CELLS USUALLY SOLITARY

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)