Potamogeton POTAMOGETON ACEAE -JUNCAOINACEAE Najas 



Blades petiolate, not serrulate, mucronate: stem stout 4. P. hwens 



Blades narrowly linear or filiform 5. P. pusillus 



1. Potamogeton cristatus Regel & Maack (Mak. F. 890). Floating herb; fls. VII; 

 fr. IX. Northern Asia, Japan; locally in An., Ku. Ponds and lakes. 



2. Potamogeton tepperi A. Benn. \f^M : fM (Fu Sheng Yen Tzu Ts'ai) (E. P. IV. 

 11: 62). Floating herb; fls. VII; fr. IX. Tropical Asia to Australia; locally in 

 An., Che., Ku. Ponds and lakes. 



3. Potamogeton crispus Linn. Curly Muckwebd $U$i (Chii Ts'ao; Marsh Weed) 

 (G.M. 71). Submersed herb; fls. IV- VII; fr. VIII-IX. Eurasia, North America; 

 locally in An., Che., Ku. Ponds and lakes. Fig. 396. 



4. Potamogeton lucens Linn. Cornstalk Weed H^fjg^^ (Shu Kan Yen Tzu Ts'ai) 

 (Hegi 1: 191). Submersed herb; fls. VIII-IX. Eurasia, northern Africa; locally 

 in An., Ku. Ponds and lakes. 



5. Potamogeton pusillus Linn. Small Pondweed $$|| (Ssu Tsao; Silk Pondweed) 

 (G.M. 72). Submersed herb; fls. VII-VIII. Eurasia, America; locally in Che., Ku. 

 Ponds and lakes. 



2. Zanichellia Linn. Horned Pondweed f^Dc<v:!Xi (Chio Ch'ien Tsao Shu) 

 Slender brg. submersed herbs with mostly opposite long-linear or filiform lvs. and 

 sheathing membranous stipules: fls. axillary, unisexual, sessile, both staminate and 

 pistillate from the same axil; staminate fl. consisting of a single stamen; anther ex- 

 serted on a slender filament; pistillate fl. with 2-8 (usually 4) carpels: carpels beaked 

 with a short style, often stipitate in fr. 2 or 3 species, widely distributed in fresh- 

 water ponds and streams: one in China. (Named for G. G. Zannichelli, 1662-1729, 

 a Venetian botanist. 



1. Zanichellia palustris Linn. var. pedicellata Rosen (H.F. 6: 568). Submersed 

 herb; fls. VII; fr. IX. Asia; locally in Ku. Ponds and streams. 



173. NAJADACEAE Naiad Family fc^Pt (Tz'ii Tsao K'o) 



Submersed marine or fresh water herbs with slender lvs. (ours with 3-12 broad- 

 based spiny teeth), fibrous roots and brg. stems: fls. unisexual, solitary and axillary; 

 the staminate with a double perianth-like envelope and a single stamen; stigmas 

 slender; carpels united: fr. a sessile drupelet with hardened pericarp. Only the follow- 

 ing genus. 



1. Najas Linn. Naiad ,;,) li^ (Tz'u Tsao Shu; Spiny Pondweed Genus) 

 Characters of the family. About 40 species, throughout the world; 2 in China. 

 (Greek: Naias, water nymph.) 

 1. Najas marina Linn. Large Naiad j^MlfcM ( Ta Hsing Tz'u Tsao) (G.M. 81). 

 Submersed herb; fls. VII; fr. IX. Eurasia, North America; locally in Ku. Ponds 

 and lakes. 



174. JUNCAGINACEAE Arrow-grass Family ;^f4 (Chih Ts'ai K'o) 



Marsh herbs with rush-like lvs.: infl. in scapose spikes or racemes: fls. perfect 

 (ours); perianth segments in two series; stamens 3-6; anthers mostly 2-celled and 

 extrorse: carpels 3-6, 1-2-ovuled, separating at maturity. 4 genera with about 20 

 species, widely distributed; one genus and two or more species in China. 



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