Ok.i>er III. 
TETRANDRIA TETRAGYNIA. 
107 
1832 Leaves ovate oblong edge with little cartilaginous scarcely pungent teeth. Corymbs pedunc. dichotomous 
1823 Leaves ovate sinuate-toothed slightly spiny. Stipules subulate, Pedunc. lax divided 
1824 Leaves ovate acute spiny smooth flat. Flowers scattered at the base of the older branches 
1825 Leaves oblong serrated, Serratures prickly-ciliated 
1826 Leaves ovate with a point unarmed nearly entire 
1827 Leaves elliptic-lanceolate acute deciduous serrated, Serratures unarmed 
1828 leaves alternate distant evergreen lanceolate attenuated both ways serrated at the end 
1829 Leaves lanceolate elliptical nearly entire reflexed at the edge. Rib villous beneath 
1830 Leaves alternate distant evergreen linear lanceolate shining serrated at end. Rib smooth beneath 
1831 Leaves alternate distant oblong obtuse crenated serrated, Serratures not prickly 
1832 Leaves oblong acuminate subserrated at the end, Pedunc. long axillary l-flowered 
1833 Leaves wedge-shaped stalked shorter on one side coarsely sawed and plaited 
1834 Leaves all elliptical stalked floating. Lower petioles submersed leafless 
1835 Leaves floating on long stalks lanceolate ovate narrowed at both ends 
1836 Upper leaves stalked elliptical narrowed at both ends the lower close together sessile linear 
1837 Leaves cordate stem-clasping all immersed 
1838 Leaves ovate acuminate opposite close. Stem dichotomous. Spike 4-flowered 
1839 Leaves ovate-lanceolate flat narrowed into the stalks. Spike many-flowered contracted 
1840 Leaves lanceolate alternate wavy serrated 
1841 Leaves linear obtuse. Stem compressed 
1842 Leaves setaceous parallel close together m two rows 
1843 Leaves lanceolate membranous flat entire, Spike ovate dense few-flowered 
1844 Leaves linear lanceolate alternate sessile broader than their stipule 
1845 Leaves linear opposite and alternate narrower than their stipule spreading at base, Stem rounded 
1846 Leaves lanceolate opposite acuminated 
1847 The only species 
1848 Branches procumbent smooth. Petals very short 
1849 Stem diffiise dichotomous. Leaves spatulate and obovate recurved. Fruit-stalks reflexed 
, . and Miscellaneous Particulars. 
I. cassine and vomitoria have bitter leaves, of which the N. American Indians make a tea, which is almost 
their only physic. At a certain time of the year they come down in droves from a distance of some hundred 
miles, to the coast, for the leaves of this tree, which is not known to grow at any considerable distance from 
the sea. They make a fire on the ground, and putting a great kettle of water on it, they throw in a large 
quantity of these leaves, and setting themselves round the fire, from a bowl that holds about a pint they begin 
drinking large draughts, which in a very short time occasion them to vomit easily and freely : thus they con- 
tinue drinking and vomiting for the space of two or three days, until they have sufficiently cleansed them- 
selves ; and then every one taking a bundle of the tree to carry away with him, they all retire to their 
habitations. 
5^16. Coldenia. So named by Linn£eus, in honor of Cadwallader Colden, an English naturalist, who published 
in 1742, an account of the plants of New York. 
317. Potamogeton. From voTct/M)?, a river, and ynTov, near. Most of the species grow wholly immersed in 
water, but liKe most aquatics, flower above its surface. It should seem, Professor Martyn observes, that the 
respiration of such truly-aquatic vegetables must be as different from those which inhale atmospheric air, as 
the breathing of fishes is from that of beasts and birds. Accordingly, they are, as Haller remarks, of a different 
texture, pellucid, like oiled paper, very vascular, harsh, and ribbed, but often very brittle; and their surface, 
like that of aquatic animals, destitute of hair or down of any kind. The leaves of aquatic plants afford shade 
and spawning places to fish, and habitations for aquatic insects and worms for their nourishment. The roots 
of P. natans are a favorite food of the swan, and that bird is in consequence erroneously considered as keeping 
ponds and lakes clear of all aquatics. Ducks eat the seeds and leaves of P. crispum. Haller informs us, that 
in the Swiss lakes P. serratum grows from ten to twenty fathoms long, forming, as it were, immense woods in 
the midst of these immense reservoirs. Most of the species may be considered as ornamental in a botanic gar- 
den, when kept within bounds or in pots. They are readily propagated by seeds or by dividmg their long roots, 
and for the most part, grow best on a clayey bottom. 
318. Ruppia. Named after Henry Bernard Ruppi, a German. He published in 1718, a Flora Jenensis. It 
is remarked by Dr. Goodenough, that the flower-stalk of this plant is spiral, like that of Valisneria, and relaxes 
or contracts itself according to the depth of the water. The truth is, the flower and leaf-stalks of all aquatics 
have a power of accommodating themselves to the depth of the water, so as just to emerge above its surface ; 
but the singula rity in Ruppia and Valisneria appears to be the employment of a flower-stem for that purpose. 
(See Valisneria.) 
319. Sagina. This plant, says Linneeus, is so called for its qualities. In Latin, sagina expresses something 
