Dicotyledones. 71 



H. OXALIS. Wood Sorrel. 



(Gr., oxys, sour, relating to the sour juice.) 



Herbs with sour juice; leaves radical or alternate, mostly of 3 obcor- 

 date leaflets. Sepals 5 and persistent; petals 5, somewhat united at 

 the base. Stamens 10, alternately longer and shorter, mostly mona- 

 delphous at the base. Ovary 5-lobed and 5-celled, the carpels dehis- 

 cing on the back. Styles 5 and distinct. Seeds 2 or more in each 

 cell. Flowers often dimorphous or trimorphous (see Botany, page 176). 



1. Oxalis violacea, L. (L., violaceus, violet-colored.) VIOLET WOOD SOR- 

 REL. Perennial, acaulescent herbs from a scaly bulb, 4 to 9 inches high. Scapes 

 umbellately several-flowered, mostly exceeding the leaves. Petals rose-violet, rarely 

 white. Open woods or rocky places. 



2. Oxalis stricta, L. (L., strictus, close, tight.) UPRIGHT YELLOW WOOD 

 SORREL. Annual or perennial. Commonly branching at the base, the branches 

 spreading, about 6 inches long. Stems leafy to the top ; flowers yellow. In woods 

 and fields. 



RUTACE^. RUE FAMILY. 



Mostly trees or shrubs. Leaves usually compound. Flowers in our 

 species dioecious or polygamous. Sepals and petals 3-5 ; stamens as 

 many or twice as many as the sepals. Pistils 2-5, distinct, or as many 

 carpels united to form a compound ovary. Fruit usually a capsule. 

 Plants secrete a pungent and acrid volatile oil; the foliage dotted with 

 pellucid glands. 



I. XANTHOXYLUM. Prickly Ash. 



(Gr., xanthos, yellow; xylon, wood.) 



Trees or shrubs. Leaves alternate, odd-pinnately compound. The 

 small whitish or greenish flowers dioecious, cymose, axillary, or termi- 

 nal. Sepals and petals 4-5. Stamens 4 or 5. Pistils 2-5, united only 

 by their styles. Stems, and often the petioles, prickly. Pods fleshy, 

 2-valved, i-2-seeded. 



i. Xanthoxylum Americanum, Mill. PRICKLY ASH or TOOTHACHE TREE. 

 Shrub with yellowish green flowers appearing before the leaves. Flowers in sessile, 

 axillary, umbellate clusters. Leaves odd-pinnate, leaflets ovate, 5-11. Bark, leaves, 

 and pods very pungent-aromatic. In woods and thickets. 



