580 CERATOPIIYLLE.E (Skaii) 



L CERATOPHYLLUM, Linn. 



. Characters and distribution of the order. 



1. C. demersnm (Linn. Sp. PI. ed. I. 992); a glabrous perennial 

 herb ; stems much-branched, floatinii; and subinerf^ed, 2-3 ft. some- 



times up to 8 ft. long ; leaves in whorls of 5-12, 1-3-times (usually 

 twice) dichotomoubly divided, often about 1 in. long ; segments 

 linear to filiform, entire or more or less remotely spinulose-serrulate ; 

 perianth-segments oblong, about Min. long; fruit ovoid or ellipsoid, 

 slightly compressed, about 3 lin. long, smooth or sparingly covered 

 with minute tubercles, narrowly or broadly winged or wingless, 

 crowned with the long slender often cur\-ed persistent style and 

 usually bearing 2jrecurved subulate or terete spines at the base. 



odr. iii. 73 ; Benih 



, Hook f.FLBrit 



Lul V. 639 ; K. Schum. in Mart. FL Bras. iii. iii. 746, /. 125 ; Hlern 



Smith d Soicerhy, E.ojl BoL xiv. /. 947 ; BC. Pre 

 FL Austral ii. 491 ; Boiss. FL Orient iv. 1202 ; 



I 

 t 



I 



Order CXXV. A. CERATOPHYLLEJE. 



(By S. A. Skan.) 



J 



Flowers monoecious. Perlauth thinly herbaceous or submem- 

 branous, equal ; segments 6-12, subvalvate, often toothed or . 



lacerated at the apex. Male : stamens 10-20, crow^ded on a flat^ or ^ 



convex torus ; filaments very short ; anthers linear-oblong, equalling 

 the perianth ; cells 2, linear, parallel, adnate, dehiscing longitudin- 

 ally; connective produced beyond the cells into a thick coloured ^ 

 usually 2- or 3-toothed appendage. Female : ovary 1, sessile, ovoid, 

 1-celled ; style terminal, linear-subulate, persistent; stigma uni- 

 lateral ; ovule 1, pendulousj anatropous. Fruit 1-seeded, leathery, 

 indehiscent, ovoid or ellipsoid, somewhat compressed, tipped with 

 the hardened style, sometimes with 2-4 spreading or reflexed spines 

 at the base, w^ingless or surrounded by a narrow or broad leathery 

 toothed wing, smooth or tuberculate. Seed pendulous ; testa mem- 

 branous ; albumen ; embryo straight, with oblong rather thick 

 equal cotyledons; radicle very short; plumule large, many-leaved. 



Aquatic herbs with elongated leafy floating branches ; leaves verticillate, 2-M 

 or dichotomously divided ; segments linear or filiform, somewhat rigid, usually 

 toothed ; flowers axillary, solitary, very small, sessile, the male and female 

 alternating at the nodes, or male at the lower nodes and female at the upper. 



DiSTiUB. Ceratopkyllum, the only genus, includes 1 or 2 or according to some 

 authorities about a dozen species, growing in fresh water in nearly all parts of the 

 world. 



