30 EUPHORBIACEAE 



3. Stillingia Hnearifolia S. Wats. Linear-leaved Stillingia. Fig. 3031. 



Stillingia Hnearifolia S. Wats. Proc. Amer. Acad. 14: 297. 1879. 

 Stillingia agymnogyna Pax & K. Hoffmn. Pflanzenreich 4"'-^: 196. 1912. 



Glabrous freely branching plants, several-stemmed from a woody base. Leaves subsessile, 

 linear, entire, 1 . 5^ cm. long ; inflorescence of several bracteate spikes, 4-7 cm. long ; staminate 

 flowers many, often reddish ; calyx 2-lobed, the tube slender, about . 5 mm. long, much shorter 

 than the 2 divergent stamens, the subtending bracts triangular, mostly shorter than the broad 

 stalked glands; pistillate flowers 4-7, scattered, 5-9 mm. long, not crowded on the rachis, the 

 perianth none, bracts and glands as those in the staminate flowers; capsule 2.5 mm. high, 3.5 

 mm. broad, the column of the gynophore more or less persistent ; seeds 3 mm. long. 



Desert and interior foothills, Lower Sonoran Zone; San Bernardino County, California, south to central 

 Lower California and western Sonora. Type locality: San Diego County, California. March-May. 



9. RiCINUS L. Sp. PI. 1007. 1753. 



A tall monoecious herb, often becoming a small tree. Leaves alternate, large, peltate, 

 palmately lobed and toothed. Flowers numerous, small, apetalous, greenish, in terminal 

 racemes, the pistillate above the staminate. Staminate flowers with a 3-5-parted calyx 

 and numerous crowded stamens; filaments branched. Pistillate flowers with a caducous 

 calyx. Ovary 3-celled, 3-ovuled; styles red, 3, united at the base, 2-cleft. Capsule sub- 

 globose or oval, separating into three 2-valved carpels. Seeds ovoid or oblong, mottled. 

 [Latin name of the plant.] 



A monotypic genus native to Africa and Asia. Type species, Ricinus communis L. 



1. Ricinus communis L. Castor Bean. Fig. 3032. 



Ricinus communis L. Sp. PI. 1007. 1753. 



Tall annual herb or in frostless regions becoming a shrub or small tree, 1-4 m. high, glabrous 

 throughout, reddish-tinged. Leaves 1.5-3.5 dm. broad; inflorescence racemose; capsule 10-15 

 mm. high, smooth or spiny; seeds about 10 mm. long, conspicuously carunculate, mottled. 



Introduced plant established in southern California and occasional in protected areas in central California. 

 Type locality: Eurasia. May-Sept. 



10. EUPHORBIA* L. Gen. PL ed. 5. 208. 1754. 



Herbs, shrubs, or trees with milky juice. Leaves simple, alternate, opposite, whorled, 

 or absent. Stipules often present. Flowers monoecious (or dioecious in some extralimital 

 species), several to numerous, staminate and 1 central pistillate surrounded by an involucre 

 forming a cyathium. Involucre gamophyllous, usually with 5 lobes alternating with 5 

 naked or variously margined glands, one or more of the glands often wanting. Staminate 

 flowers naked, monandrous, consisting of a solitary stamen jointed to the staminate pedi- 

 cel which is usually subtended by a bracteole. Pistillate flower ecalyculate or with a 

 minute calvx, apetalous, borne centrally in the cyathium on a pedicel, soon exserted from 

 the involucre and usually reflexed. Ovary 3-celled. Styles 3, bifid or entire. Capsule 

 3-celled, usually dehiscent. Seeds carunculate or ecarunculate. [Name in honor of Eu- 

 phorbus, physician to Juba 11, King of Mauretania.] 



About 1,600 species, most abundant in the warmer temperate zone. Type species, Euphorbia antiqiiorum L. 



Leaves alternate at least below the inflorescence (except decussate in E. Lathyris), equilateral; stipules wanting, 

 or if present, gland-like; seeds carunculate, or if ecarunculate, plant a shrub. 

 Shrub; glands 5, with petaloid appendages; seeds ecarcunculate. IL Agaloma. 



Herbs; glands 3-5, without petaloid appendages; seeds carunculate. 



Styles entire; glands cupped and concealed by inflexed lacerate margin; stipules gland-like; stems not 



umbellately branched. I- Poinsettia. 



Styles bifid; glands convex, not concealed; stipules absent; stems umbellately branched above. 



III. ESULA. 



Leaves all opposite, not decussate, usually inequilateral; stipules present, not gland-like; seeds ecarunculate: 

 Ijerbs. IV. Chamaesyce. 



L Poinsettia. 



Our only species. 1- ■£• criantha. 



IL Agaloma. 



Our only species. 2. E. misera. 



IIL EsULA. 

 Stem-leaves decussate; capsule 7-15 mm. long, spongy when fresh. 3. E. Lathyris. 



Stem-leaves alternate; capsule not more than 5 mm. long, never spongy. 



Stem-leaves serrate or serrulate; glands entire and rounded; seeds obviously reticulate. 



Umbel-rays mostly S, trichotomous below; capsules smooth; seeds ovoid, esculpate-reticulate. 



4. E. Helioscopia. 



Umbel-rays mostly 3, dichotomous throughout; capsules verrucose; seeds lenticular-ovoid, superficially 

 reticulate. S. E. spathulata. 



Text contributed by Louis Cutter Wheeler. 



