SPURGE FAMILY 25 



sepals 5-6, obtuse, surpassed by filaments ; capsule 4 mm. long ; seed 4 mm. long, shining, 



mottled. 



Dry hills and plains, often found in cultivated areas, Upper Sonoran Zone; Klickitat County, Washington, 

 to northern Lower California. Type locality: Columbia River near the mouth of the Willamette. June-Sept. 



3. DITAXIS Vahl ex Juss. Euphorb. 27, 110. 1824. 



Monoecious or rarely dioecious annual or perennial herbs, often woody below. Leaves 

 alternate, entire or toothed, pubescence when present in ours mostly of coarse appressed 

 malpighiaceous hairs. Inflorescence axillary, racemose, bracteate, pistillate flower usu- 

 ally 1, basal, staminate above. Sepals of staminate flowers 5 ; petals 5, equaling or sur- 

 passing the stamens; glands of disk opposite sepals. Sepals of the pistillate flowers 5, 

 somewhat elongated in age; petals 5, equaling or shorter than the sepals; glands oppo- 

 site the sepals, short, often petaloid. Stamens 5 or 10, united in a column, arranged in 

 2 ranks, the third rank if present sterile. Styles 3, once or twice cleft. Capsule 3-lobed, 

 1 seed in each cavity. [Name Greek, meaning double-ranked, referring to stamens.] 



About 43 species, natives of temperate and tropical regions of North and South America. Type species, 

 Ditaxis fasciculata Vahl. 



Bracts and pistillate calyces conspicuously fimbriate-glandular; pubescence of the upper stems of short, soft, 



spreading hairs, with few or no appressed setose hairs. 1. U. adenophora. 



Bracts and pistillate calyces not conspicuously fimbriate-glandular; upper stems mainly with appressed setose 

 hairs, or glabrous. 

 Stigma-lobes broadly dilated; low shrubs. 2. D. lanceolata. 



Stigma-lobes linear or subclavate; annuals or short-lived perennials. 



Pubescence of setose hairs mixed with appressed or crinkled pilose hairs; seeds globose-ovoid, nearly 



smooth, lightly marked with shallow reticulations. 3. D. scrrata. 



Pubescence when present of setose hairs only; seeds ovoid, faveolate, the depressions marked with 

 minute radiating ridges. 

 Herbage hairy, usually densely so; pistillate petals more or less pilose. 4. D. neomexicana. 



Herbage glabrous or with few hairs on the leaves; pistillate petals glabrous. 



5. D. californica- 



1. Ditaxis adenophora (A. Gray) Pax & K. Hoffmn. Glandular Ditaxis. 



Fig. 3020. 



Argytkamnia adenophora A. Gray, Proc. Amer. Acad. 8: 294. 1870. 

 Ditaxis adenophora Pax & K. Hoffmn. Pflanzenreich 4"'^': 65. 1912. 

 Argythamnia Clariana Jepson, Fl. Calif. 2:419. 1936. 



Perennial branching herbs, more or less purplish, 3-4 dm. high with woody caudex, upper 

 part of the stems finely pubescent with simple hairs. Leaves oblanceolate, 1.5-4.5 cm. long, veins 

 prominent on the lower surface of the leaf, pubescence of short simple hairs, appressed setose 

 hairs very sparse, margins rather finely serrate, usually with tack-shaped glands on the teeth ; 

 inflorescence congested, mostly with simple hairs ; bracts 1-3 mm. long, narrowly triangular, 

 margin with tack-shaped glands ; staminate flowers 3-4 mm. long, with few or no stalked glands ; 

 petals longer than the sepals ; pistillate sepals 4-6 mm. long, lanceolate, not white-margined, 

 densely beset with marginal tack-shaped glands ; pistillate petals clawed, ovate-lanceolate, sorne- 

 times laciniate, as long as or longer than the sepals ; ovary with coarse setose hairs, becoming 

 glabrate ; style branches dilated at the tips ; seeds irregularly and shallowly pitted, the surface 

 roughened. 



Desert slopes, Lower Sonoran Zone; rare, Coachella Valley, Colorado Desert, California, to southwestern 

 Arizona and Sonora. Type locality: Sonora. April-Aug. 



The plants of California and adjacent Arizona are less robust and more hairy than those of the typical 

 form in Sonora. Also the tack-shaped glands of the leaves are shorter and less abundant. 



2. Ditaxis lanceolata (Benth.) Pax & K. Hoffmn. Narrow-leaved Ditaxis. 



Fig. 3021. 



Serophyton lanccolatum Benth. Bot. Sulph. 52. 1844. 

 Argythamnia sericophylla A. Gray, Bot. Calif. 2: 70. 1880. 

 Ditaxis sericophylla Heller, Cat. N. Amer. PI. 5. 1900. 

 Ditaxis lanceolata Pax & K. Hoffmn. Pflanzenreich 4""'>" : 71. 1912 



Low pubescent shrubs, often dioecious rather than monoecious, 2.5-4 dm. high, stems arising 

 from woody base, erect, simple or, if branching, the branches sharply ascending. Leaves short - 

 petiolate, linear-lanceolate, in vigorous plants broadly lanceolate, entire;, 1-2.5 cm. long, densely 

 pubescent with long setose appressed hairs; inflorescence sessile; staminate flowers 3-4; sepals 

 about 2.5 mm. long, surpassed by the short-clawed ovate-lanceolate petals ; gland thickened, 

 minute, lanceolate; sepals of pistillate flowers lanceolate, 3^ mm. long, not white-margined or 

 very narrowly so; pistillate petals clawed, ovate-lanceolate, nearly equaling the sepals, adnate 

 with the thin, minute, mostly broadly triangular glands to disk at base of ovary ; ovary 3-celled, 

 densely hairy ; styles short, adnate about half their length, the free portion deeply bifid ; stigmas 

 broadly dilated; seeds grayish or brownish, faveolate, the depressions marked with minute 

 radiating ridges. 



Rocky slopes, Lower Sonoran Zone; Colorado Desert, California, east to western Arizona and south to 

 Lower California and Sonora. Type locality: Magdalena Bay, Lower California. March-Oct. 



