658 Okdee 12G.— CERATOPHTLLACEiE. 



oblong-ovoid ; stigmas 2, sessile recurved ; capsule 2-celled ; seeds 

 minute. — Small, submersed herbs, adhering to stones and pebbles. 



P. ceratopli;^lluni Mx. Lvs. diohotomously dissected ; fls. solitary, axillary. — 

 Mid. W. and S. States, in shallow streams. St. a few inches long, usually desti- 

 tute of roots and attached to stones by lateral, fleshy processes Lvs. numerous, 

 olive-green, alternate, coriaceous, divided Into many long, linear-setaceous seg- 

 ments. Fls. on short, thick peduncles, the 2 stamens and styles at length burst- 

 ing through the lacerated calyx Jl. (Lacis ceratophylla Bougard.) 



Order CXXVI. CERATOPHYLLACE^. Hornworts. 



Re/rbs aquatic, with vertieillate, diohotomously dissected leaves. Flowers mo. 



(loecioug, sessile, axillary, inim|te, with neither corolla nor calyx. Involucre 8 to 12- 



cleft. S Anthers (12 to 24) sessile. ? A simple, l-oeUed ovary. iSsed suspended, 



orthotropous, embryo with 2 pairs of cotyledons. i 



Oenus 1 only, with 6 ? species, in the streams and pools of the northern hemisphere. 

 Properties — Unimportant. 



CERATOPHYL'LUffl, L. Hornwqrt. (Gr. K&pag, a horn, (pvXXov, 

 a leaf ; alluding to the horn-like divisions of the leaves.) Character 

 the same as that of the Order. 



C. demersum L. Lvs. 6 to 8 in a whorl, doubly dichotomous, dentate-spines- 

 cent on the back ; fls. axillary ; fr. 3-spined. — If An aquatic weed in ditches, etc., 

 N. Y. to Va., W. to 111. St floating or prostrate, 8 to 16' long, filiform, with 

 numerous whorls of leaves. These are diohotomously divided into 2 or more 

 narrow, stiff segments. Fls. minute, axillary, sessile, with sessile anthers. Fr. 

 an oblong, beaked capsule, with 1 seed. Jl. — Sept. 



FIG. 692. Tiutus CaDad6D6is— naked seeds. 



