74 PLANTS OF MASSACHUSETTS. 



ORDER J23. OXALIDE^. Wood Sorrel Tribe. 



Calyx of 5 sejoals, equal, often slightly cohering at the base, 

 with 5 petals hypogynous and equal ; stamens 10, monadel- 

 phous more or less, and the 5 inner or opposite the petals longer 

 than the others ; 5 filiform styles rising from a 5-angled ovarium, 

 of 5 cells ; seeds few ; leaves alternate, generally compound, 

 rarely whorled or opposite. 



This order much resembles the preceding, and was taken from 

 it ; embraces a considerable number of plants in the hotter and 

 temperate chmes of America, especially, and at the Cape of 

 Good Hope. The plants are not very important. Many have 

 sour leaves ; some are astringent ; an Oxalis in Columbia bears 

 tubers like a potato. Only one genus in North America, and 

 4 species in this State. 



OxALis. L. 15. 5. Wood Sorrel. 



O. acetosella. L. Grows in open w^oods, on hills and moun- 

 tains, covers many parts of Saddle Mount, and makes a beautiful 

 show in the time of flowering. Leaves and flower-stalk grow 

 from the dentate root ; leaves ternate and broad, obcordate, beauti- 

 ful, and dehcate ; flower-stalk roundish, pubescent, 3-6 inches 

 high, bearing one flower, white with reddish veins ; blossoms in 

 June to July. 



Pure oxalic acid is said to exist in this plant. Taken in quan- 

 tity, this acid is a deadly poison, but a little of it is pleasant. 



O. violacea. L. Sheep Sorrel, Violet Sorrel. A smaller 

 plant, stemless hke the other, and with similar leaves, but red or 

 purplish flowers. Blossoms in May, in fields. 



0. stricta. L. Upright or Yellow Sorrel. Stem 4-8 

 inches high, with umbelliferous peduncles of yellow flowers, and 

 leaves like the other ; grows in sandy fields ; blossoms through 

 the summer. Both this species and the preceding probably con- 

 tain oxahc acid. 



0. corniculata. L. Greatly resembles the last, but has a 



