96, NAIABACEJE. 377 



ing when young. — Sy. E. B. 1428. M. vii. 17. — Whole plant 

 very slender. L. rather filiform than linear. Sheaths small, 

 close— Bait marshes. P. VI.— VIH. E. S. I. 



3. Zaknichel'lia Linn. Horned Pondweed. 



1. Z. palus'tris (L.) ; style at least half as long as the diver- 

 gent nuts. — E. B. 1844. — -Floating. L. slender, opposite, fili- 

 form. Fl. axillary, sessile. Anth. 2 — 4-celled. Style J as long 

 as fruit. Stigmas generally notched at the margin. — ^/3. Z. pedi- 

 eellata (Pr.) ; style as long as the nut. Clusters usually stalked. 

 Pedicels long. Perhaps distinct. — Sy. E. B. 1426. — Stagnant 

 water. |3. Brackish water. A. or P. V.— VUI. E. S. I. 



2. Z. polycnr'pa (Nolte) ; style scarcely -J of length of con- 

 verging sessile nute. — Much resemhling Sp, 1. — Bwanbuster 

 Loch, Orkney. Br. Syme ! S. 



Order XCYI. NAIADACE^. 



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

 fi-ee, 1 — 3. Ovary 1, superior, with 1 ovule. Style 1 ; stigmas 

 2 — 4, filiform. 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. ZosTBBA. Fl. imperfect. Stam. and pistils inserted in 

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

 Fl. naked. Anth. 1. Ovary 1; style 1; stigmas 2, 



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

 Barren fl. of 1 stamen. Fertile : style short; stigmas 2 — 4 

 filiform. 



1. Zoste'ea Linn. Grass-wrack. 



1. Z. nana (Eoth) ; 1. linear 1-veined, ped. filiform, spadix 

 short with 2 — 5 clasping bands, nuts smooth. — E. B. S. 2931. 

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

 pale-coloured throughout, ^ as broad and quite as long as the 

 inflated oblong-lanceolate spaths. Eipe seed shining black. — 

 Muddy estuaries. P. ? VH. YUI. E. S. I. 



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

 bands, nuts striate.—^. B. 467. B. vii. 4.— Plant long. L. 

 broad. Ped. rather strong. Eipe seed milky white. — Z. angw- 

 tifolia, Sy. E. B. 1430, R. vii. 3, is a slender form, growing 

 upon mud, with fewer veins in its 1. and rather longer peduncles 



