310 EUPHORBIACEAE (SPURGE FAMILY) 



sules nodding, depressed-globose: seeds obtusely quadrangular, 1 mm. long 

 or less. Plains; Colorado, east to the Mississippi, south to Mexico. 



3. Euphorbia albomarginata T. & G. Pac. R. R. Rep. 2: 174. 1857. Per- 

 ennial, slender, much branched, smooth: leaves stipulate, opposite, subor- 

 bicular or subcordate, entire, distinctly petiolate: involucre solitary, shorter 

 than the peduncles; glands transversely oval, with an entire or slightly cre- 

 nate petaloid border, which is twice as broad as the gland itself: seeds obovate, 

 somewhat rugose transversely, dull, gelatinous when moistened. Colorado 

 to Utah and southward. 



4. Euphorbia Fendleri T. & G. Pac. R. R. Rep. 2: 175. 1855. Glabrous 

 perennial, from a slender rootstock: stems delicately filiform, erect or de- 

 cumbent, dichotomous, much branched, 5-10 cm. high: leaves ovate, obtuse, 

 obliquely rounded or truncate at base; stipules subulate: involucres terminal, 

 solitary, turbinate, slightly bearded in the throat, lobes short and fimbriate; 

 glands transversely oblong, with a very narrow obscure appendage: capsule 

 deflexed, somewhat 3-lobed: seeds ovoid, transversely rugose. Throughout 

 our range and southward and eastward. 



5. Euphorbia serpyllifolia Pers. Syn. 2: 14. 1807. A prostrate spreading 



glabrous annual with obovate-oblong leaves, narrowed at the very oblique 

 ase and serrulate towards the obtuse apex (6-12 mm. long) ; stipules lanceo- 

 late, at length fimbriate at tip: peduncles as long as the petioles or longer, 

 solitary in the axils or clustered towards the ends of the branches: glands of 

 the small involucre with narrow somewhat toothed appendages: capsules 

 sharply angled, slightly drooping: seeds transversely wrinkled and pitted. 

 From California to Iowa and Texas. 



5a. Euphorbia serpyllifolia rugulosa (Engelm.) Millsp. Pitt. 2: 85. 1890. 

 More matted: leaf toothed on the longer side: seeds turgid, finely rugulose. 

 Southwestern Colorado, Mexico, and California. 



6. Euphorbia glyptosperma Engelm. Bot. Mex. Bound. Surv. 187. 1859. 

 Glabrous annual, erect and spreading: leaves linear-oblong, mostly falcate, 

 very unequal at base, slightly serrulate towards the obtuse apex (4-10 mm. 

 long) ; stipules lanceolate, setaceously divided : peduncles as long as the 

 petioles, solitary or in dense foliaceous lateral clusters: glands of the very 

 small involucre with narrow crenulate appendages: capsules nodding, sharply 

 angled: seeds quadrangular and with 5 or 6 sharp transverse wrinkles. From 

 Canada to Mexico. 



7. Euphorbia stictospora Engelm. Bot. Mex. Bound. Surv. 187. 1859. A 

 yellowish-green pubescent annual: stem 1-1.5 dm. long: leaves rounded, sub- 

 cordate, sharply serrate, 4-8 mm. long: racemes crowded with very small 

 and slender long-peduncled involucres; glands narrowly appendaged: capsule 

 pubescent, sharply angled: seeds slender, sharply quadrangular, rugose, 

 pitted. Wyoming to Mexico. 



8. Euphorbia marginata Pursh, Fl. Am. Sept. 607. 1814. A stout erect 

 annual, bright green, glabrous or pubescent, 3-7 dm. high: leaves entire, 

 ovate or oblong; the uppermost or floral leaves with conspicuous white or 

 petal-like margins, whorled or opposite: involucres 5-lobed, collected in an 

 umbel-like inflorescence with 3 dichotomous rays; glands with broad white 

 appendages: capsule depressed-globose, about 6 mm. in diameter: seeds 

 reticulate-tuberculate. From Minnesota to Colorado and Texas. 



9. Euphorbia hexagona Nutt. Spreng. Syst. 3: 791. 1826. Erect annual, 

 somewhat hairy with scattered appressed hairs: stem slender, 3-6 dm. high; 

 branches opposite and dichotomous, striate-angled : leaves all opposite, 

 short-petioled, linear-lanceolate, alternate at each end, acute, mucronulate, 

 entire; floral ones very narrowly linear: involucre hairy without and in the 

 throat, short, many-cleft; glands 5, transversely ovate, with a green ovate- 

 triangular acute appendage, twice their length: styles very short, capitate and 

 somewhat 2-lobed at the apex; carpels of the smooth capsule obtusely cari- 

 nate: seeds ovate, finely papillose. From the upper Missouri to 'New Mexico. 



10. Euphorbia dentata Michx. Fl. Bor. Am. 2: 211. 1803. A dull green 

 pubescent annual with ovate, or ovate-lanceolate, coarsely dentate, opposite, 



