CERATOPHYLLACE®, 123 
margins of lobes rounded without any keel or wing. Although 
C. truncata is mainly a southern form, yet as it occurs as far north as 
Belgium it is possible that, in some of the British stations recorded for 
C. autumnalis, C. truncata may yet be found. ; 
Autumnal Water Starwort. 
German, Herbst Wasserstern. 
ORDER LXX—_CERATOPHYLLACESA. 
Small diffusely branched rigid brittle herbs, growing in water and 
entirely submerged. Leaves sessile, verticillate, wedgeshaped, dicho- 
tomously cleft into numerous slender acute segments. Flowers mone- 
cious, sessile, axillary, solitary, very minute, bracteate, with an involucre 
cut into 10 or 12 segments. Perianth none. Stamens in the male 
flowers 12 to 20; anthers sessile, 2-celled. Female flowers with a 
1-celled ovary; ovules solitary, pendulous, orthotropous; style single; 
stigma filiform, oblique. Fruit a 1-seeded indehiscent nut, tipped 
with the hardened style. Seed solitary; albumen none; embryo with 
2 cleft cotyledons; radicle inferior. 
GENUS l—CERATOPHYLLUM. Linn. 
The only known genus of the order. 
The derivation of the name of this genus of plants is from xépa¢ (keras), a horn, 
and ¢vdAov (phullon), a leaf, the leaves being supposed to resemble little horns. 
SPECIES I-—CERATOPHYLLUM AQUATICUM. Wats. 
In Lond. Cat. ed. vi. 
Prates MCCLXXVI. MCCLXXVIU. 
C. demersum, Benth. Handbk. Brit. Bot. ed. ii. p. 12 (non Linn.). 
The only known species. 
Sus-Srecies 1—Ceratophyllum demersum. Linn. 
Prats MCCLXXVI. 
Billot, F). Gall. et Germ. Exsice. No. 3084. 
Fruit smooth, with a spine on each side near the base, and tipped 
with a long curved subulate style. 
Tn ponds and ditches. Rather common in the south of England; 
R2 
