Sparganmm SPARGANIACEAE-POTAMCGETONACEAE Potamogeioh 



171. SPARGANIACEAE Bur Reed Family l£tfif (Hei San Leng K'o) 

 Erect perennial monoecious marsh or aquatic herbs with sparingly branched lfy. 

 stems, and creeping horizontal rootstocks: lvs. sessile, linear, 2-ranked: fls. in globular 

 glabrous heads, without involucres: staminate fls. without perianth; stamens 3; 

 pistillate fls. with a perianth of 3-6 linear or spatulatc scales: pistillate heads becoming 

 bur-like in fr., an aggregate of obovoid or spindle-shaped nutlets. Only the following 

 genus. 



1. Sparsanium Linn. Bur Reed H^HM (Hei San Leng Shu; 

 Black-three-cornered-reed Genus) 

 Characters of the family. 20 species, temperate and cold regions of the northern 

 hemisphere; one in China. (Greek: sparganion, a band, referring to the ribbon-like 

 leaves.) 



1. Sparganium simplex Huds. EiMMM (San Leng Yeh P'u; Three-cornered- leaf 

 Reed) (Hegi 1: 117). Stout herb, to 2 m.; fls. VII; fr. IX; lower pistillate heads 

 on peduncles. Eurasia, North America; locally in Che., Ku. Swamps and pond 

 margins. Fig. 395. 



172. POTAMOGETONACEAE Pondweed Family m=?-~MPr (Yen Tzu Ts'ai K'o) 

 Usually submersed herbs with slender rootstocks, 2-ranked entire sometimes floating 

 lvs. and very small perfect fls. in fascicles or spikes; perianth wanting, or of 4 small 

 segments; stamens 4: fr. a small achene. 8 genera with over 120 species, in fresh 

 or salt water, cosmopolitan; four genera and 20 species in China. 



Key to the Genera 



Fls. in spikes; spike when young covered by the stipule, exserted on a 

 peduncle at maturity: carpels sessile: staminate fls. with 4 sessile 

 anthers 1 . Potamogeton 



Fls. axillary, both staminate and pistillate usually from the same axil: 

 the staminate fl. consisting of a single anther on a slender filament, 

 beside which are the 2-8 carpels of the pistillate fl., in the cup- 

 shaped involucre 2 . Zanichellia 



1. Potamogeton Linn. Pondweed gH^^M (Yen Tzu Ts'ai Shu; 



Hollow Vegetable Genus) 



Aquatic herbs with slender flaccid lfy. stems and fls. in dense cylindric terminal 

 spathaceous spikes; perianth of 4 concave segments; anthers 4, sessile on the perianth 

 segments: carpels 4, 1-seeded, drupe-like in fr. 90 species, cosmopolitan; 20 in China. 

 (Greek: potamos, a river; and geiton, a. neighbor; on account of the habitat.) 



Key to the Species 



a. Upper lvs. floating; blades oblong, elliptic, ovate or lanceolate. 



Floating lvs. small; blades 1.5-2.5 cm. long: fig. spikes not over 



lcm. long: achenes with a median cristate-dentate dorsal wing . . 1. P. cristatus 

 Floating lvs. large; blades 2-8 cm. long: fig. spikes 3-5 cm. long: 



achenes dorsally 3-ribbed; median rib sometimes narrowly winged 2. P. tepperi 

 aa. Lvs. all submersed. 



Blades orbicular, oblong, lanceolate or linear, crisped or undulate. 



Blades sessile or clasping, serrulate, obtuse: stem slender 3. P. crispus 



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