FLORA OF THE DISTRICT OF COLUMBIA. 191 



Petals pale purple to nearly white; seeds smooth or reticulate. 

 Seeds smooth; flowers on 2-flowered peduncles, loosely an-anged. 



5. G. pusillum. 

 Seeds reticulate; flowers in dense clusters 6. G. carolinianum. 



1. Geranium maculatum L. 



Woods; common. Apr.-June. Eastern U. S. 



2. Geraniiim oolumbinum L. 



Fields; occasional. May-June. Native of Eur. and Asia; naturalized in the 

 eastern U. S. 



3. Geraniiim moUe L. 



, Fields; College Park. Apr.-May. Native of Eur. ; naturalized in eastern N. 

 Amer. 



4. Geranium dissectum L. 



College Park, May, 1916 {J. B. S. Norton). Native of Eur.; occasionally adventive 

 in N. Amer. 



5. Geranium pusillum L. 



Fields about Bladensburg. May-June. Native of Eur.; adventive in N. Amer. 



6. Geranium carolinianum L. 



Dry fields; common. Apr.-May. Widely distributed in N. Amer. 

 After flowering the plants become tinged with red, presenting a characteristic 

 appearance. 



85. OXALIDACEAE. Wood-sorrel Family. 



Flowers purple ; plants stemless, the leaves all basal 1 . lONOXALIS . 



Flowers yellow; plants with leafy stems 2. XANTHOXALIS. 



1. lONOXALIS Small. 



1. lonoxalis violacea (L.) Small. Violet wood-sorrel. 



Dry woods or fields; common. May- June. Widely distributed in the U. S. 

 {Ozalis violacea L.) 



Often known as sheep sorrel; the leaves have an agi-eeable acid flavor. 



2. XANTHOXALIS Small. Yellow wood-sorrel. 



Petals about 15 mm. long, sometimes larger; stems mostly simple, erect, 30 cm. high 



or taller. Hairs of the stems and petioles spreading 1. X. grandis. 



Petals 8-12 mm. long; stems often much branched, sometimes prostrate. 

 Pedicels loosely hairy; plants tall, usually more than 30 cm. high; leaflets mostly 



2-3 cm. wide 2. X. cymosa. 



Pedicels with appressed hairs; plants usually less than 30 cm. high; leaflets usually 

 less than 1.5 cm. wide. 



Stems covered with fine, closely appressed hairs 3. X. stricta. 



Stems nearly glabrous, or with spreading hairs. 

 Capsules densely and finely appressed-hairy; stems extensively creeping. 



4. X. comiculata. 



Capsules glabrous below or nearly throughout, finely hairy at the top; stems 



usually not creeping 6. X. filipes. 



1. Xanthoxalis grandis Small. 



Moist woods; known definitely only from Plummers Island. May-June. Eastern 



U. S. (Ozalis grandis Small.) 



2. Xanthoxalis C3miosa Small. 



Mostly in moist or shaded soil; common. May-Sept. Eastern U. S. (Oxalis 

 cymosa Small; 0. comiculata stricta of Ward's Flora, in part.) 



