PONDWEED FAMILY 303 



1 J) Leaves tapering to the base; sessile or 



short-petioled P. lucens 



b. Leaves linear 



(1) Leaves 1-3 in. long; stipules free 



(a) Leaves with 2 glands at the base, 1 mm. 



wide P. pusillus 



(b) Leaves without glands at the base, 1-2 



mm. wide P. foliosus 



(2) Leaves 2-12 in. long; stipules attached 



(a) Stigma sessile or nearly so P.fiHformw 



(b) Stigma on a distinct style P.pectindtus 



Ruppia Linne 1753 Ruppia 

 (Xamed for Rupp, a German botanist) 

 Perianth none, flowers 2 or more, consisting of 2 stamens and 4 pistils, 

 cluster enclosed at first in the sheath-like base of the leaf, fruit a drupe, 

 each on a slender stalk which, like the stalk of the spadix. appears after 

 flowering ; leaves alternate, hair-like, sheathing at the base : submerged 

 aquatic in salt or alkaline water. 

 Stems 2-3 ft. long; leaves 1-3 in. long, .5 mm. or less 



wide; pedicels 4-6 in a cluster, the peduncle coiled R. maritime. 



Zannichellia Linne 1753 Zannichellia 

 (Named for Zannichelli, an Italian botanist) 

 Perianth none, flowers monoecious, 1 staminate and 2-5 pistillate flow- 

 ers in the same axil, stamen 1, pistil 1, fruit a ribbed or toothed nutlet; 

 flowers and leaf-buds at first enclosed in an envelope ; leaves thread-like, 

 whorled ; submerged aquatic. 

 Leaves 1-3 in. long, .5 mm. or less wide; fruits 2-6 



in a cluster, ( 2-4 mm. long Z.palustris 



JUNCAGIXACEAE ARROW GRASS FAMILY 



Perianth usually of 6 parts, in 2 rows, greenish, stamens 3-6. pistils 3-6, 

 united, separating into 3-6 carpels when ripe ; flowers in terminal spikes 

 or racemes on long leafless stalks ; marsh herbs with basal, half-round 

 leaves, sheathing below. 



Triglochin Linne 1753 Arrow Grass 

 (Gr. tri- } three, glocliin, point, from the 3-pointed fruit) 

 PI. 44, fig. 3. 

 Characters of the family. 



