

EUPHORBIACEAE (SPURGE FAMILY) 547 



10. E. maculata L. (MILK PURSLANE.) Prostrate ; stems puberulent or ; 

 hairy ; leaves oblong-linear, very oblique at base, serrulate upward, more or less ' 

 pubescent or sometimes smoothish, 8-12 mm. long, usually wi^h__a_b_rownrTed 

 spot .in the center ; stipules lanceolate, fimbriate ; peduncles as long as the peti- 

 bles,"in dense foliaceous lateral clusters ; glands of the small involucre minute, 

 with narrow slightly crenate usually red appendages ; pods acutely angled, pu- 

 berulent; seeds 0.4 mm. long, red, with pale envelope, sharply 4-angled and with 

 about 4 shallow grooves across the concave sides. Open places, roadsides, etc., 

 common. 



11. E. humistrata Engelm. Procumbent, puberulent or hairy ; leaves 

 elliptical or obovate, very oblique at base, serrulate toward the apex, sparsely 

 hairy underneath, 8-18 mm. long, sometimes with a brown spot above ; stipules 

 lanceolate, fimbriate ; peduncles rather shorter than the petioles, in dense 

 scarcely foliaceous lateral clusters ; involucre cleft on the back, its red or white 

 appendages truncate or crenate ; pods sharply angled, puberulent ; seeds ovate, 

 red, with pale envelope, obtusely angled, minutely roughened, 1 mm. long. 

 Rich soil, Out. to Minn., and south w. 



12. E. stict6spora Engelm. Similar in habit and pubescence ; leaves mostly 

 shorter, oval or suborbicular, not spotted ; seeds at maturity reddish-gray, 

 finely and distinctly pitted. Kan., westw. and south westw. 



2. ZYGOPHYLLfDIUM Boiss. Leaves opposite, on short petioles, not 

 oblique, with stipular glands ; stems dichotomously branched, erect; cymes 

 terminal; involucres with 5 glands; seeds tuberculate. 



13. E. hexagona Nutt. Somewhat hairy, 3-15 dm. high ; branches striate- 

 angled ; leaves linear-lanceolate, entire ; involucre hairy without and within ; 

 glands with green ovate-triangular appendages twice their length ; capsule smooth ; 

 seeds ovate. la. to Tex., w. to Col. and Mont.; also on waste ground, Wil- 

 mington, Del. (Commons). 



3. PETALOMA Boiss. Uppermost leaves with conspicuous white petal-like 

 margins, whorled or opposite, the others scattered; erect annuals, with 

 leaves equal at base and entire, and with lanceolate deciduous stipules; 

 involucres 5-lobed, in an umbel-like inflorescence. 



14. E. marginata Pursh. (SNOW-ON-THE-MOUNTAIN.) Stem stout, 3-9 dm. 

 high, erect, hairy ; leaves sessile, ovate or oblong, acute ; umbel with three 

 dichotomous rays ; glands of the involucre with broad white appendages. 

 Minn, to Mo., Col., Tex., and S. C.; spreading eastw. to O., and frequently 

 escaping from flower-gardens. 



4. TITHYMALOPSIS (Klotzsch & Garcke) Boiss. Only the uppermost 



leaves whorled or opposite; erect perennials, with entire leaves equal at 



base; stipules none; involucres mostly 5-lobed, in the forks of the 

 branches and terminal ; inflorescence umbelliform. 



15. E. cprollata L. (FLOWERING S.) Glabrous or sometimes sparingly hairy, 

 4-10 dm. high ; root deep ; stem usually simple for more than half its length ; 

 leaves ovate, lanceolate, or linear, entire, obtuse ; umbel 5(3-7)-forked, and the 

 forks again 2-3(or rarely 5)-forked; involucres long-peduncled, with showy 

 white appendages (appearing like petals), the lobes minute and incurved; pod 

 slender-pediceled, smooth ; seeds thick, 2 mm. long or more, ash-colored, slightly 

 uneven. Rich or sandy soil, N. Y. to Fla., w. to Minn, and La. ; also locally 

 naturalized in N. E. July-Oct. 



16. E. marilandica Greene. Pale green ; root or rootstock horizontal, near 

 the surface; stem 3 dm. high, trichotomous from near the base; leaves lance- 

 linear, whorled below, the upper opposite, and floral reduced to subulate bracts. 

 Sand hills, Anne Arundel Co., Md. (Greene). Not seen; description 

 compiled. 



