404 ILLUSTRATIONS OF THE NATURAL ORDERS. 



Compound ovary fivc-celled ; stigmas sessile. Capsule -bursting 

 elastically by five valves. Seeds several, without albumen, and with 

 a thick straight embryo. — Ex. Impatiens, the Balsam, or Touch- 

 me-not. Remarkable for the elastic force with which the capsule 

 bursts in pieces, and expels the seeds. Somewhat differently irreg- 

 ular blossoms are presented by the 



785. Ord. TropfCOlaceie {Indian-Cress or Nasturtium Family). 

 Straggling or twining herbs, with a pungent watery juice, and peltate 

 or palmate leaves. Flowers irregular. Calyx of five colored and 

 united sepals, the lower one spurred. Petals five ; the two upper 

 arising from the throat of the calyx, remote from the three lower, 

 which are stalked. Stamens eight, unequal, distinct. Ovary three- 

 lobed, composed of three united carpels ; which separate from the 

 common axis when ripe, ai-e indehiscent, and one-seeded. Seed 

 filling the cell, without albumen : cotyledons very large and thick. — 

 Ex. Tropseolum, the Garden Nasturtium, from South America, 

 where there are a few other species, one of which bears edible tubers. 

 They possess the same acrid principle and antiscorbutic projierties 

 as the CruciferiE. The unripe fruit of Tropasolum majus is pickled, 

 and used as a substitute for capers. 



786. Ord. limnanthaeCiE differs from the last only in its regular and 

 symmetrical blossoms, and the erect instead of suspended seeds ; the 

 calyx valvate in jestivation. — Ex. Limnanthes of California (some- 

 times cultivated as an ornamental annual), and Floerkea of the 

 Northern United States. 



787. {S\L ^l^\\A?liUyi {Wood- Sorrel Family). Low herbs, with an 

 acid juice, and alternate compound leaves ; the leaflets usually ob- 

 cordate. Flowers regular, of the same general structure as in Li- 

 nacete, &c., except the gyntecium, which in fruit forms a membra- 

 naceous five-lobed and five-celled, several-seeded capsule. Seeds 

 with a fleshy outer coat, which bursts elastically Avhen ripe, Avith a 

 large and straight embryo in thin albumen. — Ex. Oxalis, the 

 Wood-Sorrel. The herbage is sour, as the name denotes, and con- 

 tains oxalic acid. The foliage is remarkably sensitive in some spe- 

 cies. The tubers of some South American species, filled with starch, 

 have been substituted for potatoes. 



788. Ord. ZygopliyllaceJE differs from the last in the opposite, 

 mostly abruptly pinnate leaves, distinct stamens (the filaments com- 

 monly furnished with an internal scale. Fig. 379), and the styles 

 united into one. — Ex. Tribulus and Kallstroemia (introduced into 



