284 74. CALLITRICHACEA. 
1. CeratorpHytium Linn. 
1. C. demersum (L.); segments of 1. linear-filiform, fr. with 
a spe on each side near the base and tipped with the curved 
subulate style—E. B. 947.—L. 2—4 times forked, dark green ; 
segments of uppermost 1. broader and more rigid.—Ponds and 
ditches. P. VI. VII. 
[C. platyacanthum(Cham.) ; fr. winged on each side at the base ; 
has not occurred. | 
2. C. submersum (L.); segments of 1. setaceous, fr. destitute 
of spines and tipped with the short curved style-—E. B.679.— 
L. pale green. Young fr. smooth but when ripe covered with 
cylindrical tubercles.— Ponds and ditches. P. VI. VIL. 
Order LXXIV. CALLITRICHACEA. 
Fl. mostly moncecious, solitary, minute, usually with 2 white 
bracts, no perianth. Stam. 1. Filament long. Anth. reniform, 
1-celled, opening transversely at the top.—Perigone none. Ovary 
1, 4-angled, 4-celled. Styles 2, subulate. Fr. dry, 4-celled, 4- 
lobed; separating into 4, 1-seeded, indehiscent carpels. Em- 
bryo in axis of fleshy albumen. Radicle superior, long. Coty- 
ledons short, terete.—Only one genus. 
1. Canuitrricue Linn. 
1. C. verna (L.); fr. nearly sessile, lobes parallel in pairs 
bluntly keeled on the back, styles constantly erect, bracts falcate. 
—E. B. 722. R.v. 129.—Fr. small; keels of each pair of lobes con- 
verging. Floating 1. spathulate, rarely linear. Bracts shorter 
than fruit.—Common in stagnant and slowly running water. A. 
or P. IV.—IX. Water Starwort. 
2. C. platycarpa (Kiitz.); fr. nearly sessile, lobes parallel in 
pairs slightly winged on the back, styles erect in flower reflexed 
closely over the edges of the fruit, bracts faleate—E. B. S. 2864. 
R.v. 129.—Fy. twice as large as that of C. verna, pale when dry. 
L. all ovate or spathulate in British specimens.—[C. stagnalis 
(Scop.) is similar but with its lobes spreading in a cross. |—Com-~ 
mon, especially on mud. A. or P. V.—IX. 
3. C. pedunculata (DC.); fr. stalked or nearly sessile, odes 
parallel in pairs obtusely keeled on the back, styles divaricate in 
fr. reflexed over the sides of the fruit, bracts 0.—E. B. S. 2606.— 
L. linear, upper ones broader in the middle. Fr. stalked, small, 
the size of that of C. verna.—8. sessilis (Bab.); 1. linear, upper 
floating 1. ovate-spathulate, fr. sessile. This is probably the C. 
tenuifolia Peat hamulata (Kiitz.) is ike var. 8. but has fal- 
