154 CLASS VII. ORDER";!. 



A common and unprofitable intruder into every species of 

 ground, but particularly such as are dry and sandy. The root 

 leaves furnish a good example of the halberd shape or hastate 

 form. Flowers in panicled racemes small, with stamens and 

 styles on distinct plants. Valves ovate, entire, destitute of 

 grains. The acid properties of the plant are well known. — 

 May. — Perennial. 



POLYGYNIA. 



170. ALISMA. 

 Alisma Plantago; L. Water Plantain. 



Leaves ovate, acute, capsules obtusely three cor- 

 nered. Sm. 



Common in small ponds and ditches. Leaves radical, peti- 

 oled, ovate, acute, smooth, nerved, entire. Panicle decompound, 

 its branches given off in whorls with bractes. Flowers with 

 three calyx leaves and three deciduous petals of a purplish 

 white. Capsules three cornered, obtuse. — June, July. — Peren- 

 nial. 



Class VIT. HEPTANDRIA. Seven stamens. 



Order I. 310N0GYN1A. One style. 



- 171. Trientalis. Calyx seven leaved ; corolla 

 seven parted, equal; berry one celled ; juiceless. 



HEPTANDRIA. 



MONOGYNIA. 



171. TRIENTALIS, 

 Trientalis Americana. Ph. American Trientalis. 



Leaves lanceolate, serrulate, acuminate; petals acu- 

 minate. 

 Syn. Trientalis Europe a. Mx. 



