95. NAIADACEiE. 367 



liquely erect. — IL \u. 17. — Whole plant stronger than the 

 next. L. vei-y narrowly linear, formed as in Potamogeton pee- 

 Unatus. Sheaths large, inflated. — Salt maishea in' the South. 



P. vn. YIU. E. L 



2. R. rosteUdta (Koch) ; ped. short not spiral, anth.-cella 

 squarish as long as troad, nut gihbous at base obliquely ascend- 

 ing when young. R. Tii. 17. — Whole plant very slender. L. 

 rather filiform than linear. Sheaths small, close.— Salt marshes. 



P. vn. vm. E. S. I. 



■ 3. ZAifNiCHEL'iii Liiin. Homed Pondweed. 



1. Z. palus'fris (L.) ; style at least half as long as the fruit. — 

 £. JB. 1844. M. Tii. 16. — Floating. L. slender, opposite, filiform. 

 El. axillary, sessile. Anth. 3 4. celled. Style 5 as long as 

 fruit. Stigmas generally notched at the margm. — 53. Z.pedicel- 

 lata (Tr.) ; style as long as the fruit.; Clusters usually stalked. 

 Pedicels long. Perhaps distinct. — {Z. polycar'pa (Nolte), style 

 scarcely a sixth of thelength of the nut, has not been found" in 

 Britain.] — Stagnant water. /3. Brackish water. A. or P. V. — 

 vm. ' E. S. I. 



Order XCY. NAIADACEJE. 



Fl. monoecious or dioecious, in a spafii. Perianth 0. Stam. 

 freej 1^-8. Ovary 1, superior, with 1 oVule. Style 1 ; stigmas 

 2 — 4, fi l if orm. Fr. a nut enclosed in the persistent spath, 

 1-celled, 1-seeded, not bursting. Albumen 0. 'Embryo with a 

 thin skin having a lateral cleft. 



1. ZosTBEA. Fl. imperfect. Stam. and pistila inserted in 

 two rows upon one side of a spadix. Spath linear, leaflike. 

 FLnaled. Anth. 1. Oviaiy 1 ; style 1 ; stigmas 2. 



2. Xaias. Fl. imperfect, solitary, sheathed; no perianth. 

 Barren fl. of 1 stamen. Fertile ; style short ; stigmas 2 — i 

 filiform. 



1. Zoste'ea Linn. Grass- wrack. 



1. Z. mitia (Roth) ; 1. linear l-veined, ped. filiform, spadix 

 short with 2 — 5 clasping bands, nuts smooth. — i'. £. S. 2931. 

 R. vii. 2. — Plant small, scarcely 3 in. long. L. slender. Ped. 

 pale-coloured throughout, 5 as broad and qmte as long as the 

 mflated oblong-lanceolate spaths. Ripe seed shining black — 

 Muddy estuaries. P. ? MI. VIII. ' E. S. 1. 



2. Z. marina (L.) ; 1. linear 1 — 7-veined, spadix without 

 bands, nuts striate. — E. B, 467. S. vii. 4.-J?lant long. L. 



