Amiclmris. IIYDROCIIAIUDACE/E. 129 



Class II. INIONOCOTYLEDONOUS or ENDOGENOUS PLANTS. 



Stems with the woody fibres scattered irregularly, not forming a separate zone 

 of annual woody layers between the bark and pith. Embryo with one cotyledon. 

 Leaves mostly parallel-veined, alternate, entire, and sheathing at base. Floral 

 whorls usually in threes. 



ORDER CIV. HYDROCHARlDACEiE]. 



A(iuatic herbs, with dia-cious or polygamous flowers in membranous spathes ; 



regular G-parted i)eriantli, in two series (calyx and corolla), more or less tubular at 



base; stamens 3 to 12 ; ovary inferior, 1 -several-celled, with ascending ovules on 



parietal placent;ii ; fruit indehiscent ; and send without albumen. — Distinguished 



from the JVaiadacece and allied orders mainly by the inferior ovary. Perianth more 



or less tubular at base. Staminate flowers usually several and pedicelled : stamens 



distinct or united, the 2-celled anthers mostly introrse. Pistillate flowers usually 



solitary : style single : stigmas 3 to G, more or less deeply bifi<l. Fruit submerged, 



a utricle or berry, usiially many-seeded. Mostly perennials, with radical or in our 



species opposite or whorled leaves. 



A widely distributed order, of a dozen genera and perhaps 30 species, very sparhigly repre- 

 sented in Nortli America, and especially so on the western coast. 



1. ANACHARIS, Richard. Wateh-wf.ed. 

 Flowers polygamo-direcious, solitary and sessile in an axillary sessile tubular 

 2-cleft spathe. Perianth small, in the sterile flowers with 3 scarcely united greenish 

 sepals and as many narrower petals ; in the pistillate flowers with a greatly elon- 

 gated filiform tube and a G-jjartcd spreading limb. Stamens 3 to 9, Avith short 

 filaments united at base ; anthers oval, or in the pistillate flowers oblong or want- 

 ing. Ovary 1 -celled, with 3 parietal placentiP, few-ovuled. Style coherent with 

 the perianth-tube : stigmas 3, bilid or emarginate. Fruit a subglobose utricle. — 

 Slender perennials, with elongated leafy branching stems, and numerous opposite or 

 whorled sessile thin 1-nerved leaves; two or three temperate or tropical species. 



1. A. Canadensis, Planchon. Stems very slender and brittle, 1 to 4 feet 

 long, terete, rooting at the nodes : leaves dark green and ])L'llucid, in threes or fours, 

 or tlie lower opposite, linear- or lanceolatc-o])long, 3 to G lines long, acute, minutely 

 serrulate, sessile : tube of the perianth in the pistillate flowers 2 to 8 inches long; 

 limb 1^ to 2 lines in diameter, greenish-purple; sepals concave; petals recurved: 

 stigmas long, terete, emarginate: utricle included within tlie small membranous 

 s[)athe, nearly a line in diameter, 4 - G-seeded. — Ann. S: ^hxis.. Xat. Hist. 2 ser. 

 i. 8G. Elodra CamuJenxh, Michx. ; Caspary, Ilydrill. 83 <^ 123. rihmt, Xutt. 



In Mendocino County ( fVr.w/) ; Oregon (//i//, Hnurll) \ common in the Atlantic States, in 

 ponds and slow streams, and naturalized extensively in Europe. The staminate Howcin, which 

 liavo rarely heeii noticeil, are desciihed ns l)ref\'<iug from the stem and discharging their iwllen 

 upon the surface of the water, to which the ])istil!ntc arc raised by the elongated perianth-tulx?. 



