508 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



2. Erodium cicutarium (L.) L'Her. ex Ait., Hort. Kew. 2: 414. 1789. 



Geranium cicutarium L., Sp. PL 680. 1753. 



Throughout the State, up to 6,700 feet, common and often very 

 abundant on plains and mesas, February and March. Extensively 

 naturalized in the United States, from Europe. 



56. OXALIDACEAE. Woodsorrel family 



1. OXALIS. Woodsoerel 



Plants herbaceous, mostly perennial with creeping rootstocks or 

 bulbs, caulescent or acaulescent, the sap acid; leaves digitately com- 

 pound, the leaflets 3 or more, cuneate; flowers perfect, regular; sepals 

 5; petals 5, yellow or purplish pink; stamens 10, the filaments united 

 at base, 5 of them longer than the others; fruit a dehiscent 5-celled 

 capsule. 



Key to the species 



1. Petals yellow; plants caulescent; bulb none; sepals not bearing callosities; 

 capsules pubescent; leaflets 3: Section Xanthoxalis (2). 

 2. Stems decumbent to erect (3). 



3. Hairs of the stems, petioles, and pedicels spreading or retrorse; stems 

 conspicuously pilose or villous; capsules little shorter to longer 

 than the pedicels 1. O. pilosa. 



3. Hairs mostly appressed or subappressed-ascending; stems not conspicuously 



pubescent; capsules commonly shorter than the pedicels; leaflets 

 ciliate, glabrous or nearly so above, usually sparsely strigose beneath. 



2. O. stricta. 

 2. Stems prostrate, creeping (4). 



4. Rootstocks and taproot rather thick, more or less woody; leaflets sparsely 



to copiously strigose, often on both faces 3. O. albicans. 



4. Rootstocks and taproot slender, not woody; leaflets nearly glabrous or 



sparsely strigose 4. O. repens. 



1. Petals purplish pink, often drying violet; plants acaulescent, from a scaly bulb; 



sepals bearing apical callosities; capsules glabrous; flowers heterogenous: 



Section Ionoxalis (5). 



5. Leaflets 4 or more, longer than wide, broadly to narrowly wedge-shaped, 



entire or notched; longer filaments not appendaged, or with the appendage 



completely adnate to the filament; outer bulb scales several-nerved. 



5. O. GRAYI. 



5. Leaflets 3, wider than long, obreniform or V-shaped, the notch very broad; 



longer filaments appendaged, the appendage usually with a free tip (6). 



6. Outer bulb scales normaUy 3-nerved; leaf blades 1 to 3 cm. wide, with 



broadly ovate lobes usually as wide as or wider than long; scapes 



mostly 10 to 20 cm. long; callosities of the sepals 0.3 to 0.5 mm. long, 



seldom longer 6. O. metcalfe i. 



6. Outer bulb scales normally with more than 3 nerves; leaf blades 2.5 to 5 cm. 

 wide, with oblong-ovate lobes usually longer than wide; scapes 15 to 

 35 mm. long; callosities of the sepals 0.5 to 0.8 mm. long. 



7. O. AMPLIFOLIA. 



1. Oxalis pilosa Nutt. ex. Torr. and Gray,Fl. North Amer. 1: 212. 



1838. 



Xanthoxalis pilosa Small, North Amer. Fl. 25: 54. 1907. 



Ashdale, Maricopa County (Peebles 11627), 3,500 feet, May, 

 Southern Arizona, California, and Sonora. 



