256 



POLTPETALOUS ORDERS. 



bm*sting 



Fig. 180. 



sessile. Fruit a capsule, 

 elastically by five valves. Seeds 

 numerous, destitute of albumen ; ein- 

 hryo straight. . 



a. Properties : chiefly remarkable for the 

 elastic force "svith wliich tlie valves separate at 

 maturity and expel the seeds. 



Genus. — Impatiens. 



Fig. 180, a, is a branch both in flower and 

 fruit ; 6, diagram of the flo-wer brought into its 

 true position with respect to the axis, the trans- 

 verse line underneath showing the position of 

 the bract. 



428. TROP^OLACEiE, the Indian Cress Trite. — Trailing or 

 twining herls. Leaves alternate, without stipules. Sejpals 3-5, 

 colored, the lower one spurred. Petals equal or unequal. Sta- 

 mens G-10, distinct. Ovary composed of 3 or 5 carpels ; ovules 

 solitary, erect or pendulous. Fruit indehiscent, the pieces sep- 

 arable from a common axis. Seeds large, destitute of albumen, 

 filling the cell in w^hich they lie ; enibryo large ; cotyledons 

 large, thick, and consolidated. 



a. Properties : some plants of this order produce edible tubers ; they possess 

 the same acrid principle and antiscorbutic properties as the Cruciferas. 



Genera. — 1. TROPyEOL.E — Flowers irregular ; ovules pendulous — Tropseolum. 



2. LiMNANTH^ — Flowers regular ; ovules erect — Limnanthes, Florkea. 



429. Geraniace^, the Geranium Tribe. — Herbaceous plants 

 or sTirubs. Leaves simple, either opposite, or alternate with 

 peduncles opposite to them, mostly wdth stipules. Sejpals 5, 

 persistent, more or less unequal, aestivation imbricated. Petals 

 5, unguiculate, mostly convolute in aestivation. Stamens 10, 

 monadel]3hou8. . Ovary composed of fi-. isi. 

 6 carpels ; ovules solitary, pendulous ; 

 styles 5, cohering round the axis. Fruit 

 composed of five 1-seeded carpels, each 

 terminated by an indurated style, 

 which curls from the base upward 

 carrying the pericarp along with it. 

 Seeds exalbuminous, with a curved 

 folded embryo ; cotyledons leafy, con- 

 volute, and plaited together, 



a. Properties : the roots are simply and strong- 

 ly astringent ; the foliage abounds with an aro- 

 matic resinous matter and an ethereal oil. 



Genera. — Geranium, Erodium, Pelargonium, 

 Oplotheca. 



Fig. 181, a, Geranium maculatum ; b, the calyx 

 and corolla removed, showing the 10 monadelplious stamens and the .cohenng 



