38S cxxrx. natadeje. 



Z. pahistris is a 9m;\ll, mucli-brancliod, siibtnerged plant. Leaves scat- 

 tered, narrow-linear, tiat. Stipules broad, araplexicaul. — Found in ponds, 

 etc., in various parts of the colony ; and in most parts of the world in 

 similar situations. 



4. ZOSTERA, Linn. 



Flowers monoecious. Spatlie longitudinally splitting from 

 the lower part of the leaf, produced into a lamina above. 

 Spadix piano-compressed, membranous, nude at back, in front 

 covered with alternately 2-seriate stamens and ovaries. An- 

 thers oblong, subsessile, 1-celled ; pollen confervoid. Carpels 

 fewer than the anthers, 1-celled ; style subulate, persistent ; 

 stigmas 2, capillary. Utricles membranous. — Ktinth, I. c. p. 

 115; Endl. Gen. n. 1659. 



Z. marina (Sea-Grass) grows in the sea, on sandy shores all over the 

 world. Root creeping. Leaves linear, obtuse. 



Obder CXXX. AROIDEjE. 



Flowers unisexual, rarely bisexual, sessile on or sunk in a 

 spadix, which is either nude or invested with a petaloid spathe ; 

 when (in Le?n?ia) the flowers are subsolitary, the spadix is ob- 

 solete. Perianth or 3-4-6-parted, scale-like. Stamens defi- 

 nite and opposite the lobes of the perianth or indefinite or 

 solitary, hypogynous ; anthers 1-2- or many-celled, opening 

 outwards. Ovary single, free, 1- rarely 3-celled ; ovules soli- 

 tary or several, ascending or pendulous. Fruit mostly succu- 

 lent, rarely dry, indehiscent, 1-many-seeded. Embryo in the 

 centre of fleshy or floury albumen ; plumule 2-3-leaved. — 

 Mostly herbaceous plants, with acrid juices, and creeping or 

 tuberous rootstocks. Leaves usually petioled, with expanded, 

 ovate, sagittate or pedate-nerved leaves, and simple scapes 

 bearing undivided spadices. The more reduced forms of the 

 Order (as Lemna and Pistia) are small floaters. 



Tall hei'bs. Spathes white, convolute at base .... 1. Richardia. 



Terrestrial herbs. Spathes green, tubular at base . . 2. SxYLOcniTON. 



Floating herbs, with sessile, rosulate leaves .... 3. Pistia. 



Minute floating green scales 4. Lemxa. 



1. RICHARDIA, Kth. 



Spathe convolute at base ; limb expanded, marcescent. 

 Spadix cylindrical, everywhere very densely covered with 

 flowers, the lower part pistilliferous, with intermixed club- 

 shaped staminodia, the rest altogether staminiferous. Anthers 

 many, free, sessile, 2-celled ; the cells attached to a broadly 



