698 EUPHORBIACEAE 



sometimes solitary ; sepals often 5, ovate-oblong, obtuse ; petals wanting : capsules globular^ 

 5-6 mm. long : seeds oval, 4-5 mm. long. 



On plains and prairies, Texas to New Mexico and Mexico. 



22. Croton Tex6nsis (Kl. ) Muell. Arg. Annual, -1-16 dm. tall, the slender stems 

 2-3-cliotomous, the staminate plant more slender and with longer internodes and narrower 

 leaf-blades than those of the pistillate. Leaf-blades linear, lanceolate or oblong, 4-12 cm. 

 long, entire, rounded or blunt at the apex : petioles much shorter than the blades : racemes 

 few-tiowered : flowers dioecious ; staminate in racemes 1-3 cm. long ; sepals oblong to ovate- 

 oblong ; petals wanting ; stamens 8-12 ; filaments pubescent : pistillate flowers 2-4, toothed 

 or solitary ; sepals triangular ; petals wanting : capsules oval or globular, 4-6 mm. long : 

 seeds orbicular, 3-5 mm. long. 



In dry soil, Wyoming to South Dakota, Illinois, Alabama, Arizona and Mexico. 



6. CROTONOPSIS Michx. 

 Annual, slender, silvery-scurfy monoecious herbs, with branched stems. Leaves alter- 

 nate or rarely opposite : blades narrow, entire, short-petioled. Staminate flowers upper- 

 most in the clusters, each with a calyx of 5 equal sepals, 5 petals and 5 inflexed stamens 

 opposite the petals, the filaments distinct, enlarged at the top. Pistillate flowers each with 

 a calyx of 3-5 sepals, no petals, 5 petal-like glands opposite the sepals, and a 1-celled 

 ovary. Style twice- or thrice-cleft. Ovule solitary. Fruit a small scaly or spiny achene- 

 like capsule. Seed lenticular or terete, longitudinally wrinkled. 



Fruit covered with flat scales. 1. C. linearis. 



Fruit covered with spine-like scales. 2. C. spinosa. 



1. Crotonopsis linearis Michx. Stem wiry, 1-4 dm. tall, mostly branched : leaves 

 few ; blades oblong-ovate to linear-lanceolate, 1-2.5 cm. long, entire : staminate flowers 

 uppermost; calyx 1-1.5 mm. broad; sepals ovate; petals spatulate : pistillate flowers in- 

 conspicuous ; sepals 3-5, unequal : fruit scaly, ovoid-elliptic : seed ovoid, 2-3 mm. long. 



In dry sandy soil, often on dry granite rocks, New Jersey to Kansas, Florida and Texas. Summer 

 and fall. 



2. Crotonopsis spinosa Nash. Stems erect, 3-7 dm. tall, slender, the branches often 

 numerous, erect or ascending : leaves few ; blades linear to narrowly linear-oblong, 1-3 cm. 

 long, acute at both ends, green above, silvery beneath, entire, short-petioled : pedicels less 

 than 1 mm. long : calyx barely 2 mm. broad, white : sepals broadly oblong or ovate-oblong, 

 incurved : stamens exserted : fruit spiny : seed ovoid or ellipsoid-ovoid, about 2 mm. long, 

 slightly flattened, minutely pitted. 



In grassy swamps, Georgia and Florida. Spring to fall. 



7. DITAXIS Vahl. 



Monoecious or rarely dioecious herbs or shrubs, often perennial by rootstocks, with silkr 



or pilose foliage and purplish sap. Leaves alternate : blades 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. Sepals 4-5, 



valvate. Petals 4 or 5, alternate with the sepals and with the lobes of the disk. Stamens- 



of the same number as the petals or two or three times as many : filaments united into a 



column. Pistillate flowers with the sepals imbricated and smaller or rudimentary petals. 



Ovary 8-celled, each cavity with 1 ovule : styles 3, distinct, 2-cleft. Capsule 3-lobed, 



depressed, separating into 3 2-valved carpels. Seed subglobose, wrinkled, or muricate, 



sometimes crested. 



Flowers dioecious : glands abbreviated. 1. B. aphoroides. 



Flowers monoecious : glands more or less elongated. 

 Pistillate flowers with normal petals. 



Perennial: leaf-blades entire. 2. D. humilis. 



Annual or biennial : leaf-blades toothed. 3. D. Blodgettii. 



Pistillate flowers with rudimentary petals. 



Foliage shaggy-pubescent : capsules shaggy-hirsute : seeds prominently reticu- 

 lated. " 4. D. jrilosissima. 

 Foliage strigose-pubescent : capsules minutely pubescent : seeds slightly if at 



all reticulated. 5. D. mercurialina, 



1. Ditaxis aphoroides (Muell. Arg.) Pax. A low shrub. Leaf-blades obovate, el- 

 liptic, ovate or lanceolate, 1.5-4 cm. long, entire, 3-nerved, sessile or nearly so : racemes sur- 

 passing the accompanying leaves, long-peduncled, few-flowered : staminate flowers with 

 acute sepals, spatulate-obovate obtuse petals and 8-15 stamens in 2 or 3 series : pistillate 

 flowers witli lanceolate sepals and small petals : capsules 6-8 mm. broad, villous. 



On plains or prairies, southern Texas. Spring and summer. 



