EUPHORBIACEAE (sPURGE FAMILY) 309 



short; anther-cells united. Pistillate calyx 3-8-parted, persistent. Qapsule 

 3-lobed, bristly, separating into three 2-valved carpels. ;,. 



1. Tragia ramosa Torr. Ann. Lye. N. Y. 2: 245. 1826. Pisrennial,' light 

 green, bnstly with stinging hairs: stem erect, slender, often freely branched, 

 2-4 dm. high: leaves ovate-lanceolate to narrowly oblong, 1-4 cm. long, 

 serrate, cordate at base: calyx in pistillate flowers 5-Iobed, 3-braCted; in stam- 

 inate 4-5-lobed, with 4-6 stamens: capsule depressed, bristly: seeds globose 

 orange, variegated. T. nepetaefolia ramosa.— Colorado', eastward and south- 

 ward. 



4. EUPHORBIA L. Spurge 



Monoecious herbs (ours), with alternate, opposite, or verticillate leaves 

 and cymose inflorescence. Flowers included in the 4-5-lobed involucres 

 which are terminal or in the axils; the involucral-lobes alternating with as 

 many fleshy glands, which are rounded and naked or bear petal-hke or lunate 

 appendages. Sterile flowers lining the base of the involucre, each of a single 

 pediceled (or filament-bearing) stamen, joined to a minute bract (the supposed 

 rudimentary calyx). Fertile flowers sohtary in the middle of the involucre, 

 soon protruded on a long pedicel. Capsule erect or nodding, 3-lobed, spUtting 

 into three 2-valved carpels. 



Glands of the involucre with petal-like appendages iChamaesyce), 

 Leaves inequilateral and oblique at base. 

 Quitfe' entire. 

 Seeds smooth. 



Appendages conspicuous;, seeds terete -. . . . 1. E.rpetaloidea. 

 Appendages small; seeds obtusely 4-angled . . . 2. £. serpens. 

 Seeds 'somewhat roughened. 



Glands broader than long, with fan-shaped appendages . 3. E. albomarginata. 

 Glands longer than broad, with crescent-shaped append- 



' . 4. E. Fendleri. 



' ' Serrate or dentate. 



Glabrous. ' ' ' 



Seeds pitted, faintly if at all rugose 5. K. iserpyllifolia. 



Seeds rugose, not pitted . ." 6. E. glyptosperma. 



Pubescent . . . 7. E. stictospora. 



Leaves with the two sides at the base similar. 

 Appendages very large and conspicuous; leaves alternate . 8. E. marginata. 



Appendages small; leaves opposite 9, E. hexagona. 



Glands of the involucre naked (without petal-like appendages). 



Leaves opposite iPoinseUia), , ' • : ; '■ ■ ^ 



.. Ovate or orbicular-oblong, coarsely dentate . . . . 10. E. dentata. 

 Oblong-linear or linear, nearly entire. 



Branched from the base, spreading 11. E. Aliceae. 



Stem simple (at least below), erect ..... 12. G. cuphosperma. 

 Leaves alternate or scattered (TifA^moZufi). .<<, ,,< 



Entire; glands semilunate. 

 Stems tufted, low and stout . . . . '. . 13. E. robusta. 

 Stems few, taller and nlore slender ..... 14. E. montana. 

 Serrate or dentate. 

 Annuals. 



Stems simple below . . '. . . . . 15. E. arkansana. 



Stems branched from the decumbent base . ' . "' • 16. E. manca. ' ' 



Biennial; stem branched from the base t .... 17. E. commutata. 



1. Euphorbia petaloidea EngeI'm. Bot. Mex. Bound., Surv. ,185. 1859. 

 Glabrous annual, low, freely branched, procumbent:. leaves all similar, oblong- 

 linear, obtuse or retuse, attenuate to the scarcely' obhc[ue base: involucres 

 solitary, campanulatg, Ipbes hairy beneath the glands which are about as long 

 as the lobes; appendages 'conspicuous, white, ovate or orbicular, entire or 

 crenulate: capsules globose-depressed: seeds cinereous, nearly smooth, oblong- 

 ovoid. — Sandy plains; from the Rocky Mountains' to the Mississippi river. 



2. Euphorbia serpens II. B. K. Nov. Gen. 2: 52. 1817. Glabrous or glau- 

 cescent annual, witn filiform prostrate stems, often rooting: leaves round- 

 ovate, obtuse or cordate at base; stipules membranaceous, triangular: pe- 

 duncles longer than the petioles, sohtary in the axils: glands sfilverform, 

 shorter than the lobes of the involucre; appendages minute, crenulate: cap- 



