754 NAIADACEZ. [Zostera 
6. ZOSTERA, Linn. 
Marine submerged plants. Rhizomes slender, branched, creep- 
ing and rooting at the nodes, often matted. Stems short, slender, 
leafy, compressed. Leaves distichous, alternate, narrow-linear, 
grass-like, 1-5-nerved, sheathing at the base; sheaths stipuliforns, 
with inflexed margins. Flowers moneecious, the males and females 
placed alternately upon one face of a narrow spadix enclosed within 
the dilated membranous base of a leaf. Perianth wanting. Male 
flowers: Anther solitary, sessile, oblong, cylindric, curved, 1-celled, 
dehiscence longitudinal; pollen confervoid. Femaie flowers: Car- 
pel solitary, laterally attached above the middle, narrowed into a 
short subulate style; stigmas 2, capillary ; ovule pendulous from 
the apex of the cell. Ripe carpel oblong, membranous, bursting 
irregularly. Seed pendulous; testa membranous, often striated ; 
embryo large, deeply grooved, the linear incurved cotyledonary end 
sunk in the groove. 
Three or four closely allied species are known, found in shallow water on 
the shores of most temperate regions. 
Leaves 3-9 in. x ;4-;4 in., truncate or notched at the tip. 
Spadix with transverse appendages, one folded over each 
carpel ays a he oe oh «. 1. Z. mana. 
Leaves 9-18in. x ~4-Ain., rounded at the tip .. .. 2. Z. tasmanica. 
1. Z. nana, Roth, Enum. Pl. Phen. Germ. i. 8.—Rhizomes 
slender, matted. Leaves 3-9 in. long, rarely more, ~,—;4,in. broad, 
narrow-linear, truncate or obscurely notched at the tip, with 3-5 
faint parallel nerves on each side of the stout midrib and distant 
transverse veinlets, margins thickened. Floral sheaths or spathes 
4-1 in. long, on peduncles of equal length, the blade of the leaf con- 
tinued above the sheath, the sheath itself much wider than the 
blade. Spadix 6-12-flowered, its margins with transverse mem- 
branous appendages folded inwards, one over each carpel. Stigmas 
usually protruding through the slit of the spathe. Fruit about 
jin. long, oblong, obscurely striate —Benth. Fl. Austral. vil. 176; 
Kirk in Trans. N.Z. Inst. x. (1878) 392. Z. Muelleri, Irmisch ex 
Aschers. in Linnea, xxxv. (1867-68) 168. 
NortH anp SouTH Istanps, StEwart IstanpD: Muddy and sandy shores 
throughout, usually between high- and low-water marks. Widely distributed 
in temperate seas. 
9. L. tasmanica, Martens ex Aschers. in Linna@a, xxxv. (1867-68) 
168 (?).—Rhizomes slender, wide-creeping. Leaves 9-18 in. long, 
4-1 in. broad, narrow-linear, rounded at the tip, not truncate, with 
1-3 stout nerves on each side of the midrib and several finer ones 
between, cross-veinlets distant. Flowers and fruit not seen.— 
%. marina, Hook. f. Handb. N.Z. Fl. 742 (not of Linn.). 
NortH anp SoutH Is~tanps: Not uncommon in sandy or muddy places 
along the coasts, often in water of considerable depth. 
