ENDOGENOUS OR MOXOCOTVLKDONOU3 PLANTS. 



487 



two stamens; the fertile, of a one-celled ovary; in fruit a utricle 

 they are a kind of minute and greatly reduced Araceie, a>nnectin£ 

 that order with the next. 



933. Ord. NaiatlnCCfC (Pondweed Family). Water-plants, with 

 cellular leaves, and sheathing stipules or hascs : the flowers incon- 

 spicuous, sometimes perfect. Perianth simple and scale-like, or 

 none. Stamens definite. Ovaries solitary, or two to four and dis- 

 tinct, one-seeded. Albumen none. Embryo straight or curved. — 

 Ex. Potamogeton (Pondweed), Najas, Ruppia, 'Zostera ; the two 

 latter in salt or brackish water. 



934. Ol'd. AlismacctB ( Water-Plantain Family). Marsh herbs, 

 with the leaves and scapes usually arising from a creeping rhizoma ; 

 the former either linear, or bearing a flat limb, which is ribbed or 

 nerved, but the veinlets commonly reticulated. Flowers regular, 

 perfect or polygamous, mostly in racemes or panicles, not on a spa- 

 dix. Perianth double, the three petals commonly different from the 

 sepals, so as evidently to represent a calyx aiid a corolla. Seeds soli- 

 tary in each carpel or cell, straight or curved, destitute of albumen. 

 — Ex. Alisma (Water-Plantain), Sagittaria (Arrowhead); belong- 

 ing to the proper Alisma Family, which has the seed (and conse- 



FIG. 1212. Whole plnnt of T.cmna minor, mngnified, bearing a stnminatc monandrous flow- 

 er 1213. An individual with a diandrous perfect flower ; which at 1214 is seen separate, with 

 its spathe. highly magnified. 1215. Flower of Xemna gibba, much magnified 1216 Vertical 

 highly magnified section of the pistil and the containc-1 ovule of Lemna minor 1217 The 

 fruit, and 1218, its section, showing the seed. 1219. Section through the highly magnified 

 eeed and large embryo. 



