EUPHORBIACEiE. 336 EUPHORBIA, 



comes a tree, although an herbaceous annual with us. From its seeds is ex- 

 pressed the well known castor-oil of the shops For this purpose it is exten- 

 sively cultivated in many parts of the U. States. Jl., Aug. Castor-oil Bean. 



3. ACA'LYPHA. 

 Flowers monoecious. Sterile. — Calyx 3 — 4-partcd ; stamens 

 8 — 16, united at base. Fertile. — Calyx 3-parted, segments 

 coniiivent, persistent ; styles 3, elongated, 2 — 3 parted ; cap- 

 sule 3-celled, cells 1-seeded. 



The Greek name for the nettle, which this plant resembles. It is com- 

 pounded of a., privative, xaXo«, beautiful, and ci(pr). toucli. Herbaceous or 

 shrubby. Lvs. alternate, stipulate. 



A. Virgi'nica. 



Pubescent ; leaves on short petioles, oblong-lanceolate, serrate ; involucrum 

 cordate, ovate, acuminate, nerved and toothed. An annual, branching plant, 

 in dry and gravelly soils. Stem erect, 12 — 18 inches high. Leaves Snerved, 

 2 — 3 inches long and i — |as wide, obtuse, hairy. Pistillate flower at the base 

 of the peduncle of the staminate spike. Involucrum of the Iruit axillary, on 

 a short stalk, shorter than the leaves, its margin cut half way down into long, 

 acute segments. Aug. Ann. Three-seeded Mercury. 



4. EUPHO'RBIA. 



Flowers moncecious, mostly achlamydeous ; involucre 



monophyllous, subcampanulate, with 4 — 5 petaloid segments 



allernaling with as many external, glatuMike teeth. Slerilrjl. 



12 or more; stamen 1; filament articulated in the middle. 



Fertile Ji. solitary, central ; ovary pedicellate; styles 3, bifid; 



capsule 3-lobed, 3-celled; cells 1-seeded. 



Named for Euphorbus, physician to Juba, King of Mauritania, who first 

 used these plants in medicine. Herbs or shrubs. Lvs. generally simple, 

 sometimes v/aiiting. 



* Heads of flowers in involucrate umbels. Cauline leaves alternate. 



1. E. corolla'ta. 



Erect ; caul'me and floral leaves oblong, narrow, obtuse ; inner segments of 

 the invo'ucrn obovate, petaloid ; umbel 5-rayed, then 3-rayed and forked. Jn 

 dry fields. Stem slender, erect, 1 — 2 feet high, generally simple and smooth. 

 Leaves 1 — 2 inches long, often quite linear, very entire, scattered on the stem, 

 verticillate and opposite in the umbel. The umbel, as in other species, con- 

 sists of about 5 verticillate branches from the summit of the stem, each of 

 which is subdivided into 3, and finally into 2 peduncles. Corolla-like invol- 

 ucre large, white, showy. Jl., Aug. Per. Large-flowered Spurge. 



2. E. HELIOSCO'PIA. 



Erect; floral leaves obovate, cauline ones wedge-form, serrate, smooth; 

 7imbel 5-rayed, then 3-rayed and forked. A milky weed in cultivated grounds, 

 remarkable for the symmetry of its vegetation. Stem smooth, erect, 8 — IG 

 inches high. Leaves scattered, | — ]i inch long, rj as broad at the rounded or 

 refuse apex, finely and sharply serrate, entire, and tapering to the base. 

 Umbels subtended by a large involucre of 5 obovate leaves. Each of the 5 

 rays is pilose with scattered hairs and subdivided into an uinbellet of 3 rays 

 with a 3-leaved involucel, and these finally into 2 or more pedicellate fascicles. 

 Capsules smooth. Jn., Jl. Ann. Sun Sjjurge. 



