SPURGE FAMILY 415 



Ovary superior, 3 (4 or 1) -celled, with one or two pendulous ovules in eacli cell. 

 Styles or stigmas as many or twice as many as the cells of the ovary. Capsule 

 commonly 3-lobed, 3-valved. Embryo straight, the flat cotyledons almost as wide 

 as the fleshy or oily endosperm. — Genera about 220, species about 4500, all conti- 

 nents, chiefly tropical. 



Bibliog. — Scheele, A., Beitrage zur Kenntnis der Euphorbiaceae (Linnaea 25:580-588, — 

 1825). Baillon, M. H., Etude generale du groupe des Euphorbiacees, 1-684, — 1858. Bentham, 

 Geo., Notes on Euphorbiaceae (Jour. Linn. Bot. Soc. 17:185-267, — 1878). Parry, C. C, New 

 genus of Euphorbiaceae (West Am. Sci. 1:13-14, — 1885). Engelmann, Geo., Papers on Euphor- 

 biaceae (Botanical Works, 433-449, — 1887). Ferguson, A. M., Crotons of the United States 

 (Eep. Mo. Bot. Gard, 12:33-73, pis. 4-31,-1901). Pax, F. and Hoffmann, K., Euphorbiaceae- 

 Hippomaneae (Engler, Pflzr. 4"^-=*: 1-319, figs. 1-58, — 1912) ; Acalypheae-Chrozophorinae 4"^-«: 

 1-142, figs. 1-25,-1912); Acalypheae-Mercurialinae (4""-'': 1-473, figs. 1-67,-1914); Acaly- 

 pheae-Plunkenetiinae (4"^-»:l-108, figs. 1-24,-1919); Acalypheae-Eicininae (4"'"": 112-134, 

 figs. 26-29,-1919); Crotonoideae-Acalypheae-Acalyphinae (4"'-":l-178, figs. 1-3,-1924). 

 Johnston, I. M., [Notes on Securinega and Tetracoccus] (Univ. Cal. Publ. Bot. 7:441—442, — 

 1922). Haber, J. M., Anatomy and morphology of the flower of Euphorbia (Ann. Bot. 39:657- 

 707, figs. 1-112,-1925). Anon., Turkey Mullein in hay (Mo. Bull. Cal. Dept. Agr. 19:50,-1930). 



Staminate flowers with a calyx, the pistillate with or without a calyx, neither kind borne in an 

 involucre. 

 Ovary with 2 ovules in each cell ; anthers erect in the bud ; flowers pediceled, disposed in um- 

 bellate axillary clusters ; shrubs. 



Leaves alternate; capsule 3-celled 1. Securinega. 



Leaves opposite; capsule 4-celled 2. Tetracoccus. 



Ovary with 1 ovule in each cell ; shrubs or herbs. 

 Leaves alternate. 



Anthers in the bud bent inward and downward. 



Ovary 1-celled ; annual 3. Eremocarpus. 



Ovary 3-celled ; perennial herbs or sometimes woody at base 4. Croton. 



Anthers erect in the bud. 



Corolla present; flowers in much reduced axillary spikes or clusters; herbage 



mostly grayish or silvery; herbs 5. Argythamnia. 



Corolla none ; flowers in distinct spikes or racemes. 



Herbage pubescent or canescent; leaves crenate or serrate, with stipules; 

 shrubs. 

 Style very short or none ; stigmas 3 ; leaves silvery-canescent beneath.. 



6. Bernardia. 



Styles 3, filiform-dissected; leaves green-puberulent 7. Acalypha. 



Herbage glabrous ; stipules none. 



Leaves peltate; stamens many; styles 3, imited at base; shrub 



8. ElCINUS. 



Leaves not peltate ; stamens 2 to 6 ; styles 3 ; herbs. 



Stamens 2 ; styles distinct ; herbage glabrous 9. Stillingia. 



Stamens 3 or more; styles (in ours) united below; herbage (in 



ours) hispid 10. Tragia. 



Leaves opposite ; flowers mostly dioecious ; styles 2; annual 11. Mercurialis. 



Flowers all vsdthout calyx, borne however in a calyx-like involucre which simulates a single flower ; 

 leaves alternate or opposite 12. Euphorbia. 



1. SECURINEGA Comm. 



Shrubs, ours with entire obovate small leaves. Flowers dioecious. Calyx im- 

 bricated, bearing an entire or irregularly 5-lobed disk. Staminate flower : sepals 

 5 or 6, distinct; stamens in ours 3 to 7; rudiment of pistil absent or present, often 

 2 or 3-cleft. Pistillate flower : ovary 3 or 4-celled, each cell 2-ovuled; styles 3 or 4, 

 simple, united at base, stigmatic down the inside. Seeds in ours with a caruncle. — 

 Species 10, all continents. (From Latin securis, an axe, in reference to the hard- 

 ness of the wood.) 



1. S. fB/Sciculata Jtn. var. hallii Jepson. Intricately branched shrub 2 to 6 

 feet high, with rigid branches and spinescent branchlets; herbage subglabrous; 

 leaves in fascicles, their blades obovate, 2 to 3 lines long; sepals 6, minute; capsules 

 globose, minutely and thinly pubescent, 3 lines long. 



