ENDOGENOUS OR MONOCOTYLEDONOUS PLANTS. 



487 



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

 they are a kind of minute and greatly reduced Aracese, connecting 

 that order with the next. 



933. Ord. NaiadaceEB {Pondweed Family). Water-plants, with 

 cellular leaves, and sheathing stipules or bases : 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, Euppia, Zostera ; the two 

 latter in salt or brackish water. 



934. Ol'd. Alismaceae ( 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 and a corolla. Seeds soli- 

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

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

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



riG. 1212. Whole plant of Lemna miDor, magnified, bearing a staminate 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 Lemna gibba, much magnified. 1216. Vertical 

 highly magnified section of the pistil and the contained ovule of Lemna minor 1217 The 

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

 seed and large embryo. 



