I 



EUPHOEBIACEAE (SPURGE FAMILY) 547 



10. E. maculata L. (Milk Purslane.) Prostrate ; stems puberulent or 

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

 pubescent or sometimes smoothish, 8-12 mm. long, usually with 'a brown-red 

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

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

 with narrow slightly crenate usually red appendages ; pods acutely an^ded pu' 

 berulent ; see(?s 0.4 mm. long, red, with pale envelope, sha7^}ly i-aiigled 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, Ont. 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 loith lanceolate deciduous stipules: 

 involucres b-lobed, in an umbel-like infiorescence. 



14. E. marginata Pursh. (Snow-on-the-Modntaix.) 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. TITHYMAL6pSIS (Klotzsch & Garcke) Boiss. Only the uppermost 



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



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

 branches and terminal; infiorescence umbelliform. 



15. E. corollata 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 sho^^■y 

 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. marildndica 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. 



