Buppia. NAIAD ACE^E. 193 



4. LIL.5JA, HBK. 



Flowers monoecious, without perianth. Male flowers mingled with the pistillate 

 or in distinct spikes, of a single nearly sessile 2-celled rounded anther subtended by 

 a hyaline bract. Ovaries naked, sessile and erect, in the axils of radical leaves and 

 in pedunculate exserted spikes, the upper with short styles, but the lower styles 

 much elongated ; stigmas capitate ; ovules solitary, erect. Fruit coriaceous, oblong- 

 lanceolate, indehiscent, compressed and ribbed, the upper narrowly winged, the 

 lower wingless and laterally toothed at the summit. Seed with membranous testa 

 and straight narrow and entire embryo. An aquatic or marsh annual (?) herb, 

 with fibrous roots and radical grass-like leaves sheathing at base. Only the follow- 

 ing species. Ifeterostylus, Hook. 



1. L. subulata, HBK. Leaves | to 1 foot long or more, a line or two broad, 

 several-nerved, thin : spikes crowded, a half to an inch long, on peduncles shorter 

 than the leaves : staminate bracts narrowly oblong, obtuse, half a line long, twice 

 longer than the anther : radical fruits 3 lines long, the filiform style often 1 to 3 

 inches long ; upper fruits elliptical, acute, somewhat smaller. Nov. Gen. i. 222, 

 t. 63. Heterostylus gramineus, Hook. Fl. Bor.-Am. ii. 171, t. 185. 



School Station, near San Francisco (Kellogg) ; in ponds near Searsville, San Mateo County 

 (Bolandcr) ; on the Columbia River, Scouler. Apparently not distinct from the Chilian plant on 

 which the species was founded, though usually larger. The Searsville specimens are especially 

 well developed, being 2 feet high or more and the fruiting spikes 1 inches long. 



5. ZAWNICHELLIA, Micheli. HORNED PONDWEED. 



Flowers monoecious, axillary, sessile or nearly so. Male flowers of a single naked 

 stamen, with elongated filament and 2-celled anther. Fertile flowers usually in the 

 same axils, of 2 to 5 sessile or shortly stipitate ovaries in a membranous cup-shaped 

 perianth or spathe ; style short ; stigma peltate ; ovule solitary, suspended, ortho- 

 tropous. Fruit an obliquely oblong coriaceous nutlet, somewhat compressed, beaked. 

 Seed with membranous testa. Embryo slender, the attenuate cotyledonary end 

 bent into a coil. Very slender immersed branching aquatics, with very narrow 

 and filiform flattened mostly opposite leaves, not sheathing, and with small free 

 membranous stipules. Several species are described, perhaps all varieties of a single 

 one. 



1. Z. palustris, Linn. Stems 2 inches to 2 feet long or more, branching and 

 leafy : leaves ^ to 2 or 3 inches long : fruit somewhat incurved, often more or less 

 toothed on the back, 1 to 1| lines long, about twice longer than the style, usually 

 becoming shortly stipitate and frequently also pedunculate. Z. major, Bonn. ; 

 Nees, Gen. iii, t. 46 ; Reichenb. Icon. Fl. Germ. vii. 9, t. 16. 



In fresh-water ponds and slow streams ; collected in California by Douglas, in springs at the 

 base of Monte Diablo (Brewer), in ditches on Oakland Hills (Bolander), and near Santa Barbara 

 (Mrs. Eliuood Cooper) ; found also in Utah and New Mexico, in the Atlantic States, and in most 

 quarters of the globe, excepting South America and Africa. 



6. RUPPIA, Linn. DITCH-GRASS. 



Flowers perfect, without perianth, 2 or more approximate on a spadix enclosed 

 in the sheathing base of a leaf, becoming long-exserted. Anthers 2, sessile, of 2 dis- 

 tinct cells, transversely dehiscent. Ovaries 4, at first sessile, with nearly sessile 

 depressed stigmas, and solitary suspended campylotropous ovules. Fruit obliquely 



