ORDER CVIII. — EUPHORBIACE^. 495 



8. A. serpenta'ria, (L.) Stem herbaceous, pubescent, erect, genicu- 

 late and flexuous, geniculate at tlie bas^e. Leaves cordate, oblonir, acu- 

 minate, slightly hairy. Flowers on radical peduncles, sonietitnes^under 

 the surface of the ground. Limb of the perianih lanceohite, ventrieoso 

 at the base. — ^. Through the summer. Dry soils. 8 — 12 inches. 



Virginia Snake-root. 



4. A. hasta'ta, (Nutt.) Ste^n flexuous, simple, erect and pro«mibent. 

 Leaves somewhat cordate, hastate, acute, auriculate. Peduncles radi- 

 cal; lip of the perianth ovate. — Mountains. 



Order CVIL— EMPETRA'CE^. {Crowbernj Family.) 



Flowers dioecious. Perianth consisting of 2 — 4 rows of im- 

 bricated hypogynous scales. Stamens equal in number to the 

 scales, and alternate with them. Anthers with 2 distinct cells. 

 Ovary superior, seated in a fleshy disk, 6 — 9-celled. Style 1. 

 Stigma multifid, radiating. Fruit baccate, 2-ceIled, 2-seeded. 

 An evergreen shrub, with flowers in the axils of the leaves. 



Genus I— CERATIO'LA. Mich. 20—2. 

 (From the Greek keration, a little horn, from the shape of the stigma.) 



Genus the same as the Order. 



1. C. ericoi'des, (Mich.) An evergreen shrub, with virgate branches, 

 somewhat verticillate when young, tomentose. Leaves linear, glabrous, 

 rigid, with the margins revolute, verticillate, 3 — 1 in a whorl. Flowers 

 axillary, sessile. Scales of the calyx persistent, tomentose. Berries 

 email, 2-seeded. — ^. Aug. — Sept. Dry soils. 4 — 8 feet. 



Order CVIII.— EUPHORBIA'CE^. 



Flowers monoecious, or dioecious. Perianth lobed, inferior, 

 frequently with glandular or scaly appendages. Sterile flowers. 

 Stamens 1 — 12, or numerous. Fertile flowers. Ovary 1, su- 

 perior, sessile or stiped, usually 3-celled. Ovules solitary, or 

 twin, suspended. Styles usually 3, sometimes united. Fruit 

 usually consisting of three dehiscent cells, separating from the 

 axis. Seed suspended. Herbaceous or shrubby plants, usually 

 with milky juice. 



ANALYSIS. 



1. stamens 4 or less 2 



Stamens more than 4 6 



2. Stamens 4 Pachyaandra, 10 



Stamens less than 4 * 



8. Involucre corolla-like Euphorbia, 1 



Involucre calyx-like ^ 



4. Flowers dioecious Borya, 11 



Flowers monoecious ^ 



6. Flowers separate Trogia, 8 



Several in an involucre StiUingia, i 



