( 456 .) 
ZOSTE'RA * * 
Linnean Class and Order. MoNas'ciAf, Mona'ndria %. 
Natural Order. Fluvia'les §, V ent. — Lindl. Syn. p. ‘248. ; In- 
trod. to Nat. Syst. of Bot. p. 289. — Loud. Hort. Brit. p. 541. — Mack. 
FI. Hibern. p. 204 — Naiades, Juss. Gen. PI. p. 18. — Sm. Gram, 
of Bot. p. 66. — Hook. Brit. FI. (4th ed.) p. 423. — Najadeae, Rich, 
by Macgilliv. p.387. — Juncales ; sect. Nayadinac ; type, Naya- 
daceag ; Burn. Outl. of Bot. v. i. pp. 403 and 413. — Inundatag, 
Linn. 
Gen. Char. Flowers monoecious ; boih sterile and fertile ones 
arranged in two rows upon one side of a common spadix (see fig. 3). 
Spatha oblong, formed of the base of a leaf, splitting lengthwise. 
Sterile Flower (see fig. 3, a. & fig. 4). Calyx none. Corolla none. 
Jlntlier (see fig. 3, a. and figs. 4 & 5.) cylindrical, tapering at each 
end, sessile, of 1 cell. Pollen mixed with branched fibres (see 
fig. 5). Fertile Flower (see fig. 3, b. and fig. 6). Calyx none. 
Corolla none. Germen (see fig. 3, b. & fig. 6.) egg-shaped, com- 
pressed, 2-edged. Style (see fig. 3, b. & fig. 6.) 1, terminal, 
cylindrical, curved outwards. Stigmas 2, thread-shaped, pointed, 
curved. Fruit (see fig. 8.) a bladder-like drupe or utricle ), cylin- 
drical, pointed, somewhat juicy, 1-celled, without valves, 1-seeded. 
Seed (see fig. 9.) oval, striated. Embryo (see fig. 10.) central, 
cylindrical, curved. Radicle inferior, (that is, opposite to the scar 
of the seed). 
Distinguished from other genera in the same class and order, by 
the two kinds of flowers being inserted, in two rows, upon one side 
of a common spadix, and both destitute of calyx and corolla ; by 
the leaf-like spatha ; and by the sessile anther. 
One species British. 
ZOSTE'RA MARI'NA. Sea Grass-wrack. Common Grass- 
wrack. 
Spec. Char. Stem roundish. Leaves strap-shaped, entire, 
somewhat 3-nerved. 
Engl. Bot. t. 467. — Hook. FI. Loml. t. 35. — FI. Dan. t. 15. — Linn. Sp. PI. p. 
1374. ; It. W. Goth. p. 166. t. 4.— Huds. FI. Angl. (2nd ed. ) p. 395.— Willd. Sp. 
PI. v. iv. pt. I. p. 179. — Sm. FI. Brit. v. i. p. 7. ; Engl. FI. v. i. p. 5. — With. (7th 
edit.) v. iii. p. 668. — Gray’s Nat. Arr. v. ii. p. 37. — Lindl. Syn. p. 251. — Hook. 
Brit. FI. p. 385. — Maer. Man. Brit. Bot. p. 224. — Lightf. FI. Scot. v. l. p. 530. — 
Tliomp. PI. of Berw, p. 1. — Davies’ Welsh Bot. p. 2. — Hook. FI. Scot. p. 259. — 
Grev. FI. Edin. p. 188. — Burn. Outl. of Bot. v. i. p. 414. — FI. Devon, pp. 146 and 
113. — Jolinst. FI. of Berw. v. i. p. 2. — Winch’s FI. of Northumberl. andJAurh. p. 
58. — Bab. Prim. FI. Sam. p. 101. — Irv. Lond. FI. p. 85. — Cow. FI. Guide, ;p. 54. — 
Baines’ FI. of Yorksh. p. 97. — Mack. Catal. PI. of Irel. p. 78. ; FI. Hibern. p. 26.7. 
— Alga, Ray’s Syn. pp. 52 & 53 ; the whole genus. 
Fig. 1. Plant of its usual size. — Fig. 2. Larger variety. — Fig. 3. Part of a Spadix, 
with the Flowers. — Fig. 4. A perfect Anther. — Fig. 5. One laid open to show the 
contents. — Fig. 6. Germen. — Fig. 7. Young Seed taken from it. — Fig. 8. Seed- 
vessel. — Fig. 9. Ripe Seed. — Fig. 10 — Embryo deprived of its covering. —All, ex- 
cept figs. 1 & 2, magnified . — From Sir J. W. Hooker’s beautiful plate in Flora 
Londinensis. 
* From zoster, Gr. a girdle, or ribbon ; which the leaves somewhat resemble, 
t See fol. 83, note t. % See fol. 49, note f. § Sec fol. 350, a. 
