EUPHORBIACEAE 699 
2. Ditaxis hümilis (Engelm. & Gray) Pax. Perennial. Stem slender, much 
branched, pubescent, the branches spreading, 1-3 dm. long: leaf-blades ovate, oblong or 
oblanceolate, 1-3 em. long, entire, narrowed into short petioles : flowers in axillary clus- 
ters, the staminate with petals a little longer than the 5 sepals and longer than the lobes of 
the disk : pistillate flowers with 5 sepals and three usually twice 2-cleft styles : capsules short- 
pedicelled, much depressed, 4-6 mm. in diameter, 3-4-lobed: seeds oval-globose, about 2 
mm. long, muricate. 
On prairies, Kansas to Louisiana and Texas. Spring to fall. 
3. Ditaxis Blodgéttii (Torr.) Pax. Annual or biennial, sparsely pubescent. Stems 
usually branched at the base, the branches erect, ascending or decumbent, 1-6 dm. long, 
often slightly zigzag: leaf-blades oval, elliptic or oblong, or spatulate at base of stem, 1.5- 
4 cm. long, acute or acuminate, serrate, somewhat acuminate at the base, short-petioled : 
staminate flowers 3-5 in a cluster: pistillate flowers usually solitary ; calyx strigillose ; 
sepals linear-lanceolate, acute, 3-5 mm. long; petals greenish white, oblong, slightly 
longer than the sepals, or shorter and more acute in pistillate flowers : capsules 3-lobed, 4-5 
mm. broad, strigose : seeds nearly 2 mm. long, reticulated. 
Insandy soil, Key West, Florida. Spring to fall. 
4. Ditaxis pilosíssima (Benth.) Heller. Perennial, densely pubescent with woolly 
hairs. Stems erect or ascending: leaf-blades elliptic, elliptic-ovate or oblong-spatulate at 
base of stem, 2-5 m. long, obtuse or acutish, several-nerved, sessile: racemes surpassing the 
leaves, few-flowered : pedicels 3-10 mm. long: calyx pubescent : sepals narrowly lanceolate or 
linear-lanceolate, becoming 5-7 mm. long, acuminate : petals narrowly spatulate or cuneate, 
about as long as the sepals, acute, rudimentary in the pistillate flowers: glands villous- 
hirsute : capsules 3-lobed, about 1 cm. broad, densely hairy : seeds subglobose, 4-5 mm. in 
diameter, reticulated with sharp ridges. 
On prairies, Texas. Spring to fall. 
. 5. Ditaxis mercurialina (Nutt.) Coulter. Perennial. Stem slender, strict, usually 
simple, channeled, silky, 1-6 dm. high. Leaf-blades ovate to narrowly lanceolate or ob- 
lanceolate near the base of the stem, 2-5 cm. long, undulate, sessile, often strongly 3-nerved, 
glabrate : flowers in terminal and axillary racemes ; the staminate with lanceolate or linear- 
lanceolate, acute, ciliate sepals, and spatulate-oblong, undulate petals : pistillate flowers 
with 5 spreading lanceolate sepals, 3 times as long as those of the staminate: petals want- 
ing : capsules depressed, 6-9 mm. in diameter, somewhat silky, 3-lobed: seeds globose- 
ovoid, 4 mm. long, pointed, wrinkled, indistinctly 2-crested. 
In dry soil, Kansas and Arkansas to Texas. Spring to fall. 
8. MERCURIALIS L. 
Annual or perennial herbs or shrubby plants, with firm or succulent tissues. Leaves 
opposite : blades entire or often toothed. Flowers mostly dioecious, apetalous. Staminate 
flowers in more or less elongated spikes or racemes. Calyx membranous, of 3 valvate 
sepals. Stamens 8-20: filaments distinct : anthers opening lengthwise. Pistillate flowers 
with a calyx of 3 sepals. Ovary 2-celled : styles 2, distinct or nearly so: stigmas entire. 
Ovules solitary in each cavity. Capsule usually 2-lobed. Seed solitary in each cavity, with 
a smooth or tuberculate crustaceous testa. 
.. l. Mercurialis ánnua L. Annual, glabrous. Stems 2-6 dm. tall, more or less 
widely branched : leaf-blades thinnish, ovate to lanceolate, acute or slightly acuminate, 
serrate with rounded teeth, or crenate: petioles 5-15 mm. long: staminate flowers in 
interrupted spikes which surpass the leaves: pistillate flowers clustered in the axils: 
capsules 2-lobed, 4—5 mm. broad, hispid : seeds subglobose, 1.5 mm. in diameter, pitted. 
In waste places, South Carolina to Florida and Texas and in other partsof North America. Native 
of Europe and Africa. 
9. RICINÉLLA Muell. Arg. 
Dioecious shrubs, with glabrous or rarely tomentose foliage, the branchlets sometimes 
spine-tipped. Leaves alternate, often clustered at thenodes: blades membranous or parch- 
ment-like, entire. Flowers apetalous : staminate nearly sessile in axillary clusters. Stamens 
8-15: filaments short, distinct: anthers versatile. Pistillate flowers solitary, long-pedi- 
celled. Ovary 3-celled : styles 3, distinct, lacerate. Ovules solitary in each cavity. 
Capsule 3-lobed, crustaceous. Seed solitary in each cavity, with a smooth testa. 
1. Ricinella Vaseyi (Coulter) Coult. & Fish. A shrub branching from the base, the 
branches 1.5-2 m. tall, puberulent, or glabrous in age. Leaves rather few, clustered on the 
