Ceratophyllaceae. Hornwort Family. 
Submerged aquatic herbs with jointed stems. Leaves in whorls, 2-3 
times dichotomously dissected into linear segments. Flowers monoecious, 
axillary, inconspicuous. Perianth wanting, its place supplied by a cleft 
persistent involucre. Stamens numerous, the filaments very short or 
wanting. Pistil 1; ovary 1 - Fruit a nutlike achene. 
Ceratophyllum L. Hornwort. 
Characters of the family. 
1. C. demersun le Stems filiform, branching freely; leaves 6-9 in each 
whorl, 1.5-2 cm. long, twice or thrice equally forked, the divisions 
linear, roughened by minute spines on the margin; involucral segments 
1.5 mm long, green; achenes oval, somewhat flattened, 5-6 mm. long, borne ; 
on short stalks about 1 mm. long, bearing 5 needle-like tapering appendages, | 
4-6 mn. long, one at the apex, two at the base, strongly reflexed. 
Frequent in shallow water along lake shores. 
Pe 
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