GERANIACE^E. (GERANIUM FAMILY.) 105 



4. OXALIS, L. WOOD-SORREL. 



Sepals 5, persistent. Petals 5, sometimes united at base, withering after 

 expansion. Stamens 10, usually monadelphous at base, alternately shorter. 

 Styles 5, distinct. Pod oblong, membranaceous, 5-celled, more or less 5-lobed, 

 each cell opening on the back ; valves persistent, being fixed to the axis by 

 the partitions. Seeds 2 or more in each cell, pendulous from the axis, ana- 

 tropous, their outer coat loose and separating. Embryo large and straight in 

 fleshy albumen; cotyledons flat. Herbs, with sour watery juice, alternate or 

 radical leaves, mostly of 3 obcordate leaflets, which close and droop at night- 

 fall. Several species produce small peculiar flowers, precociously fertilized in 

 the bud and particularly fruitful ; and the ordinary flowers are often dimor- 

 phous or even trimorphous in the relative length of the stamens and styles. 

 (Name from ous, sour.) 



* Stemless perennials ; leaves and scapes arising from a rootstock or bulb ; leaflets 



broadly obcordate ; flowers nearly V broad ; cells of the pod few-seeded. 



1. O. AcetOS&la, L. (COMMON WOOD-SORREL.) Rootstock creeping 

 and scaly-toothed; scape \-flowered (2-5' high); petals white with reddish 

 veins, often notched. Deep cold woods, Mass, to Penn., L. Superior, and 

 northward ; also southward in the Alleghanies. June. (Eu.) 



2. O. violacea, L. (VIOLET W.) Nearly smooth; bulb scaly,- scapes 

 umbellately several-flowered (5- 9' high), longer than the leaves; petals violet. 

 Rocky places and open woods ; most common southward. May, June. 



* * Stems leafy, branching; peduncles axillary ; flowers yellow; cells several- 



seeded. 



3. O. COrniculata, L. (YELLOW W.) Annual or perennial by running 

 subterranean shoots, erect or procumbent, strigose-pubescent ; stipules round 

 or truncate, ciliate; peduncles 2 - 6-flowered, longer than the leaves, pods 

 elongated, erect in fruit. Rare ; on ballast, etc. ; indigenous in Mo. (Bush), 

 and southwestward. (Cosmopolitan.) 



Var. stricta, Sav. Stem erect, somewhat glabrous to very villous ; stipules 

 none. (0. stricta, L.) Common. May -Sept. Varies greatly. 



4. O. reciirva, Ell. Like var. stricta of n. 3 ; leaflets larger (-!' 

 broad), usually with a brownish margin ; flowers larger (6 -8" long). Penn. 

 to S. 111., and southward. 



5. IMPATIENS, L. BALSAM. JEWEL-WEED. 



Calyx and corolla colored alike and not clearly distinguishable. Sepals 

 apparently only 4 ; the anterior one notched at the apex and probably con- 

 sisting of two combined ; the posterior one (appearing anterior as the flower 

 hangs on its stalk) largest, and forming a spurred sac. Petals 2, unequal- 

 sided and 2-lobed (each consisting of a pair united). Stamens 5, short; fila- 

 ments appendaged with a scale on the inner side, the 5 scales connivent and 

 united over the stigma ; anthers opening on the inner face. Ovary 5-celled ; 

 stigma sessile. Pod with evanescent partitions, and a thick axis bearing sev- 

 eral anatropous seeds, 5-valved, the valves coiling elastically and projecting 

 the seeds in bursting. Embryo straight; albumen none. Leaves simple, 

 alternate, without stipules, in our species ovate or oval, coarsely toothed, peti- 



