194 OXALIDACEAE 



Stems atid branches ridged, angled or winged. 2. L. striatum. 



Stems and branches terete or essentially so. 3. L. Virginianum. 



b. Inner sepals glandular-toothed, outer sepals entire or toothed. 



4. L. medium. 

 B. Styles partially united. 5. L. sulcatum. 



1. Linum usitatissimum Iv. Elax. (Mau. p. 578; I. F. /. 2258.) 

 Along roadsides, railways and in waste places, fugitive from Eu. — Penn. 

 sylvania : Northampton ; Phii<adei<phia ; Dauphin ; Lancaster ; 

 Erie ; ai<i<egheny. 



2. Linum striatum Walt. Ridged YELLOW FtAX. (Man. p. 579; I. 

 F.y. 226^.) In bogs and swamps, rarely in drier ground, Ont. to Conn., 

 Fla., Ark. and Tex. — Pennsylvania : Northampton ; Bucks ; Mont- 

 gomery ; Berks ; Chester ; Dauphin ; Lebanon ; Lancaster ; Cam- 

 bria ; Fayette. 



3. Linum Virginianum L. Wild or SlEnder Yellow Flax. 

 (Man. p. 579 ; I. V.f. 2260. ) In shaded situations, N. Eng. to Ga.^Penn- 

 sylvania : Northampton ; Montgomery ; Delaware ; Chester ; Lan- 

 caster ; Schuylkill ; Franklin ; Columbia ; Centre ; Allegheny. 



4. Linum medium (Planch. ) Britton. STIFF YELLOW Flax. (Man- 

 p. 579; I. F.y. 2262.) In dry soil, Ont. to Fla. and Tex.— Pennsylvania : 

 Erie, Presque Isle. 



5. Linum sulcatum Riddell. Grooved Yellow Flax. (Man. p. 

 579 ; I. F.y. 2364. ) In dry soil, Ont. to Man., south to Ga., west to Tex., 

 rare near the Atlantic coast.- — Pennsylvania : Lackawanna ; Hunting- 

 don, Birmingham. 



Family 3. OXALIDACEAE Lindl. Wood-sorrel Family. 

 1. OXALIS L. 



Plants acaulescent ; corolla white, pink or rose-purple. 

 Scape terminated by a single flower ; corolla pink ; capsule globular. 



1. 0. Acetosella. 

 Scape terminated by several flowers ; corolla rose-purple : capsule ovoid. 



2. O. violacea. 

 Plants caulescent : corolla yellow. 



Stems and petioles strigilose with decidedly appressed hairs. 



3. O. stricta. 

 Stems and petioles villous or with loosely spreading hairs. 



Pedicels with erect or appressed hairs. 

 Longer filaments glabrous. 

 Sepals ciliate nearly all around ; leaflets bright green. 4. 0. Bushii. 

 Sepals ciliate only at the apex ; leaflets reddish purple. 



5. O. rufa. 

 Longer filaments ciliate above or throughout. 

 Sepals ciliate nearly all around : petals 6-10 'mm. long ; leaflets wholly 

 green. 6. O. Brittoniae. 



Sepals ciliate only at the apex or near it: petals 12-16 mm. long: leaf- 

 lets brown margined. 7. 0. grandis. 

 Pedicels with villous hairs. 8. 0. cymosa. 



