364 



EUPHORBIACEAE. 



[Vox,. II. 



3. CROTONOPSIS Michx. Fl. Bor. Am. 2: 185. 1803. 



Annual slender silvery-scurfy monoecious herbs with branched stems, narrow alternate 

 or rarely opposite short-petioled leaves, the flowers in terminal and lateral clusters. Stamin- 

 nate flowers uppermost in the clusters, with an equally 5-parted calyx, 5 petals and 5 in- 

 flexed stamens opposite the petals, the filaments distinct, enlarged at the summit. Pistillate 

 flowers with a 3~5-parted calyx, no petals, 5 petal-like glands opposite the calyx-segments, 

 and a i-celled ovary; ovule i; style twice or thrice cleft. Fruit a small scaly or spiny 

 achene-like capsule. Seed lenticular or terete, longitudinally wrinkled; embryo straight 

 in fleshy endosperm. [Greek, Croton-like.] 



Two known species, natives of the southeastern 

 United States. 



i. Crotonopsis linearis Michx. Croton- 

 opsis. (Fig. 2294.) 



Crotonopsis Uncarts Michx. Fl. Bor. Am. 3: 186. pi. 46. 

 1803. 



Silvery, covered with peltate somewhat fringed 

 scales, except on the green upper surfaces of the 

 leaves. Stem wiry, 4'-! % high, much branched; 

 leaves oblong-ovate to linear-lanceolate, %'-i%' 

 long, entire; staminate flowers with an equally 

 5-parted calyx, the petals spatulate; calyx of the 

 pistillate flowers unequally 3~5-parted ; achcne 

 ovoid-elliptic; seed ovoid, i"-i#" long. 



In dry sandy soil, New Jersey to Kansas, south to 

 Florida and Texas. July-Sept. 



4. DITAXIS Vahl; Juss. Euphorb. 27. 1824. 



Monoecious herbs or shrubs, perennial by rootstocks, silky or pilose, the sap purplish. 

 Leaves alternate, entire, or rarely toothed, often strongly nerved. Flowers in axillary or 

 axillary and terminal clusters, often racemed, usually bracted. Staminate flowers often 

 crowded at the ends of the racemes; calyx 4-5-lobed, the lobes valvatc; petals 4 or 5, alternate 

 with the calyx-lobes and with the lobes of the disk; stamens of the same number as the petals 

 or two or three times as many, united into a column. Pistillate flowers with the calyx-lobes 

 imbricated and smaller petals, the ovary 3-celled, each cavity with i ovule; styles 3, short, 

 once to thrice cleft. Capsule 3-lobed, depressed, separating into 3 2-valved carpels. Seeds 

 subglobose, wrinkled, or muricate, sometimes crested; embryo straight in the fleshy endo- 

 sperm. [Greek, double-ranked, in allusion to the stamens.] 



About 20 species, natives of temperate and tropical regions. 



Flowers in terminal and axillary racemes; leaves sessile. I. D. mercurial ina. 



Flowers in axillary clusters; leaves short-petioled. 2. D. humilis. 



i. Ditaxis mercurialina (Nutt.) Coult. Tall Ditaxis. (Fig. 2295.) 



Aphora mercurialina Nutt. Trans. Am. Phil. Soc. (II.) 



5: 174. 1833-37. 

 At gyrothamnia mercurialina Muell. Arg. Linnaea, 



34: 148. 1865. 

 Ditaxis mercurialina Coult. Mem. Torr. Club, 5: 213. 



1894. 



Stem slender, strict, usually simple, channeled, 

 silky, 4 / -2 high. Leaves alternate, ovate to nar- 

 rowly lanceolate, io // -2 / long, undulate, sessile, 

 often strongly 3-nerved, glabrate; flowers in terminal 

 and axillary racemes; staminate flowers with lanceo- 

 late or linear-lanceolate acute ciliate calyx-segments, 

 and spatulate-oblong undulate petals; pistillate flow- 

 ers with a 5-parted calyx, the segments lanceolate, 

 spreading, 3 times as long as those of the staminate, 

 petals none; capsule depressed, 2"-4}4" in diame- 

 ter, somewhat silky, 3-lobed; seeds globose-ovoid, 

 2" long, pointed, wrinkled, indistinctly 2-crested. 



In dry soil, Kansas and Arkansas to Texas. Lower 

 leaves sometimes oblanceolate. April-July. 



