238 TETRANDRIA— TETRAGYNLY. Sagina. 



In salt-water ditches. 



Perennial ? August, September. 



Herb submersed. Roofs fibrous, in tufts, from several of the lower 

 joints of the long, slender, round, much branched, leafy stem. 

 Leaves alternate, linear, extremely narrow, more or less acute, 

 channelled, single-ribbed from about the middle upward, entire; 

 dotted with brown or purple towards the edges ; clasping the 

 stem with their sheathing, somewhat dilated, base. Spikes usually 

 2-fiowered, on short, solitary, axillary stalks. Fl. alternate, ver- 

 tical, as distinct on their common stalk as those of any Fotamo- 

 geton, and inclosed within the sheath of the neighbouring leaf, 

 as it appears, till impregnation is accomplished ; my account in 

 Engl. Bot. being, in this particular, incorrect. Professor Hooker 

 has rightly explained the process. After flowering, the flower- 

 stalk, often spiral, is greatly lengthened, rising to the surface of 

 the water, and carrying with it the 4 impregnated germens, each 

 raised on its own long and firm stalk, produced likewise after 



. the ani/ters are fallen. Each germen becomes an ovate, pointed 

 seed, the size of Millet, with a hard shell, that does not burst. 

 Dr. Hooker has admirably illustrated the history of this curious 

 plant, and has named the parts of the seed so as, surely, to 

 leave no room for any improvement. The germination of the 

 plant, when properly investigated, must show which is the real 

 plumula. 



83. SAGINA. Pearl- wort. 

 Linn. Gen. 68. Juss. 300. Fl.Br. 199. Lam. <. 90. Gcertn. t.\29. 

 Nat. Ord. Canjophylletv. Linn. 22. Jiis.s. 82. 



Cal. inferioi', of 4 ovate, concave, equal, widely spreading, 

 bluntish, permanent leaves. Petals 4, ovate, obtuse, en- 

 tire, shorter than the calyx, alternate with its leaves, 

 spreading ; sometimes wanting. Filam. thread-shaped, 

 ascending, shorter than the cal. and opposite to it. Antli. 

 of 2 roimdish lobes. Germ, superior, ovate. Styles ter- 

 minal, short, rather spreading. Stigmas obtuse, downy. 

 Caps, ovate, of 1 cell, and 4 ovate, separate, equal valves. 

 Seeds numerous, minute, rough, attached, each on its own 

 stalk, to a central cylindrical receptacle. 



Small, generally smooth, herbs, with opposite, narrow, en- 

 tire leaves, and axillary, solitary, stalked, small, greenish 

 or -white Jlowers. 



1. S. procmnbens. Procumbent Pearl-wort. 



Stems procumbent, smooth. Leaves minutely pointed. 

 Petals half as long as the calyx. 



