S20 



naiadAce.'e 



3. Z. pedunciddta, a less common form, has a stamen of inter- 

 mediate length, with a 2-chambered anther, long ^/y/t;5, large 

 stigmas, and stalked carpels. 



4. Z. polyeeh'pa, a rare form, occurring in the Orkney Islands, 

 has a very short stamen with a 2-chambered anther, 5 — 6 sessile 

 carpels, with very short ■ilyhs and large stigmas. 



_^ 6. ZosTiJRA (Grass- 



--wj^gj ip::^ ^ wrack). — Grass-like, sub- 

 merged marine plants 

 with creeping rhizomes; 

 compressed stems ; alter- 

 nate, long, linear, sheath- 

 ing leaves with adherent 

 stipules ; flowers monce- 

 cious, arranged altern- 

 ately in two rows on a 

 long, linear, membranous 

 spadix, enclosed in a 

 spathe ; perianth absent ; 

 stamen. i, sessile, 1- 

 cl.aQibered ; carpels each 

 with I style, 2 stigmas, 

 and I ovule. (Name from 

 the Greek zoster, a girdle 

 or riband, from the form 

 of the lea\"es.) 



I. Z. marina (Common 

 Grass-wrack). — A com- 

 mon plant in the sea, 

 near low-water mark, with 

 long, cord - like stems. 

 bright green grass-like 

 leaves, 1 — 3 feet long, 

 3 — 7-veined, and long, 

 leafy sheaths or spathes 

 to the bead-like rows of 

 numerous simple flowers. 

 The dried leaves and stems are collected, under the name of 

 Alva, for stuffing mattresses and packing glass. — Fl. July — 

 September. Perennial. 



2. Z. nana (Dwarf Grass-wrack), an uncommon species, differs 

 in having leajies not more than 6 in. l(jng and i — 3-veined, and 

 fewer flowers in a shorter spathe, with 2-7-5 infle.^ed membranous 

 appendages or clasping bands. — l'"l. April — August. Perennial. 



zoSTIiRA makIka {totnino7i (^ras.'i-nnnrk). 



