138 PETALOIDEJE. 



7. P. rnfescens (reddish P.) In ditches and slow streams. 

 Submersed leaves lanceolate, narrowed at both ends, pellucid j 

 floating leaves obovate, blunt, narrowed into a short stalk, some- 

 what leathery in texture, having usually a purplish tinge. Spikes 

 on long stalks, dense. Flowers reddish. Forde bog. (E. B. t. 

 1286.) P. vn. 



8. P. natans (sharp-fruited broad-leaved P.) In ditches, 

 ponds, and slow streams. Stems round and much branched. 

 Lower submersed leaves linear ; upper leaves numerous, floating, 

 on long stalks, ovate, 2 or 3 inches long. Flower-stalks axillary, 

 round, contracted just beneath the spike. Flowers dull green. 

 Forde bog. Bovey Heath. (E. B. t. 1822.) P, vi. vn. 



RUPPIA. EUPPIA. 



R. maritima (sea Ruppia.) In salt-water marshes and 

 ditches. Stems long and slender, much branched. Leaves al- 

 ternate, linear, with an inflated membranous sheath at then 1 base. 

 Flower-stalk long and spirally twisted. Nut ovoid. Goodring- 

 ton Marsh. Marshes at Exminster and Powderham. Salt- 

 ditches near Starcross. (E. B. t. 136.) B. vn. vni. 



ZANICHELIiXA. HORNED PONDWEED. 



Z. palustris (common horned Pondtveed.) In ditches and 

 stagnant water. Plant floating. Stems long, thread-like, and 

 branched. Leaves opposite, linear, having a grassy appearance. 

 Flowers axillary, sessile ; sterile flower with one stamen, bearing 

 a 4-celled anther ; fertile one with 4 or 5 stalked germens. Mill- 

 pond at Lympstone, FL D. (E. B. t. 1844) A. or P. v.-vm. 



ZOSTERA. GRASS-WRACK. 



Z. marina (broad-leaved Grass-wrack^) In the sea, from 

 whence it is thrown up by the tide. Leaves grassy, long and 

 linear. Flowers imperfect, the stamens and pistils inserted in two 

 rows upon one side of the flat, thin spadix. Frequent on the 

 shores of Torbay. Teignmoth. Exmouth, etc. (E. B. t. 467.) 

 P. ? vii. vni. 



