124 OXALIDACE.E. Oxalis. 



smooth : petioles 1-3 inches long, hairy. Peduncles nearly smooth. Umbel or cyme simple, 

 2 - 3-flowered ; or 2-forked, each division with a 2 - 3-flowered cymule. Sepals oblong- 

 lanceolate, rather acute. Petals obovale, twice the length of the calyx. Styles hairy : stigmas 

 capitate. Capsule prismatic, somewhat hairy : cells 7 - 8-seeded. Seeds obovoid, compressed, 

 with 6-8 longitudinal ridges, and strongly wrinkled transversely ; enclosed in a thick rather 

 fleshy epidermis, which splits on the back, and retracting elastically, throws the seed out of 

 the capsule. 



Common in fields, road-sides and cultivated grounds ; flowering from May to September. — 

 I am confident that this plant is usually perennial, or at least lives through two seasons. The 

 specific name is very inappropriate. O. corniculata of Pursh and Michaux seems to be only 

 the procumbent state of this species. 



Order XXVII. BALSAMINACE^E. A. Richard. The Balsam Tribe. 



Calyx of 5 deciduous, colored sepals ; the 2 upper (anterior) ones commonly 

 united into one, the lowest (posterior) one spurred or gibbous. Corolla hypo- 

 gynous, 4-petalled ; the petals united by pairs (so that they are, apparently, 

 only 2). Stamens 5, hypogynous, more or less connected above. Ovary 6- 

 celled, with the placentae in the axis : stigmas 5, distinct, or more or less united. 

 Capsule 5-celled, somewhat fleshy, bursting elastically by 5 valves, septifragal 

 (rarely drupaceous). Seeds several in each cell, with a straight embryo, and 

 destitute of albumen. Cotyledons large and flattish : radicle short. — Succulent, 

 herbaceous (mostly annual) plants, with a watery juice. Leaves simple, with- 

 out stipules (Arn.). 



1. IMPATIENS. Linn.; Wight ^ Am.prodr.Jl. Ind. Or. \.p. 135; Endl. gen. 6060. 



BALSAM. LADY'S SLIPPER. 

 [ Named in allusion to the sudden bursting of the ripe seed vessels by the slightest touch.] 



Sepals apparently only 4, from the union of the 2 upper ones. Petals 4, apparently only 2, 

 from the union of the lateral ones on each side. Filaments 5, more or less united at the 

 apex : anthers opening longitudinally or transversely. Cells of the ovary formed by mem- 

 branous projections of the placenta; which occupy the axis of the ovary, and are connected 



