CERATOPHYLLACEAE 509 
Sepals 3-15: petals about as many: 
plants if shrubby not with pulpy 
fruit: endosperm even. Fam. 2. RANUNCULACEAE, 
Sepals 3 (or 4): petals 6: fruit 
pulpy: endosperm channe Fam. 3. ANNONACEAE. 
Carpels more or less coherent or united 
into cone-like structures, or im- 
mersed in the pulpy receptacle. o 
Sepals valvate. Fam. 
3. ANNONACZAE. 
Sepals imbricate d. Fam. 4. MAGNOLIACEAE. 
Flowers aineciou us: vines with simple leaves. Fam. 5. MENISPERMACEAE. 
Water plants: emersed or floating leaves with 
peltate blades. 
Carpels several and distinct. 
Carpels not in a fleshy receptacle: sepals 
and petals 3 or 4 each: stamens 3-1 
Carpels immersed in a fleshy receptacle: l 
a ms petals numerous: amens Fam. 6. CABOMBACEAE. 
inde Fam. 7. NELUMBONACEAE. 
Carpe els aed ‘into a compound pistil. Fam. 8. NYMPHAEACEAE, 
Stamens few and definite, “the DE NACE spenmé 
by hinged valves, except in Podophyllum 
Herbs: E es with simple or ternate blades . Fam. 9. PODOPHYLLACEAE. 
Shrubs : Ea with pinnately or digitately com- 
pound, sometimes 1-foliolate blades Fam. 10. BERBERIDACEAE. 
Famity 1. CERATOPHYLLACEAE — Hornwort FAMILY 
Annual aquatie herbs. Leaves whorled: blades cleft or finely dis- 
sected. Flowers monoecious. Calyx o 12 narrow toothed or cleft 
sepals. Corolla wanting. Androecium of 10-24 stamens with short fila- 
ments. Gynoecium 1-carpellary: stigma subul it an achene, 
sometimes spine-arme in cod by the following genus only. 
1. CERATOPHYLLUM L. Submerged plants with sessile leaf-blades, the 
divisions mostly thrice forked. Flowers sessile in the leaf-axils.—Followin ng are 
the only known species.—Sum. or all year ibang e MOSSES. COON- 
TAILS. FISH-BLANKETS. BORN WEDE. HORNWORTS. 
Leaves 6-9 in a Mou segments BDin tote ds achenes 
with a spine on either side of the base. 1. C. demersum. 
Leaves 9-12 in a whorl; segments bristly-toothed : achenes 
fringed with spines. 2. C. echinatum. 
Achene unarmed, short- beaked. 3. C. submersum. 
1. C. demersum L. Stem 3-12 dm. long: leaves rather rigid; blades 1-2 times 
forking: Bim elliptie to Reim pe erose: stamens slightly exserted: style 
igma exs achene-body  ovoid, 
low 
various provinces, Fla. to La., Calif, and 
S Can.—(W. I., Mez., O. W.) 
eng, margined.— ow streams and ponds, 
various provinces, Fla. to Calif. and S Can. 
b Stem long: 
leaves flaccid: "blades 3—4 times forking, the 
i epus bristly toothed: ee -body ellip- 
oid, 4 mm. long, pi ineless, sparingly warty.— 
Ponis, S. in Fla.— (0. W.) 
