430 EUPnORBIACE^. (SPUEGE FAMILY.) 



Order 97. EUPHORBIACE^. (Spurge Family.) 



Plants usually with a milky acrid juice, and monoecious or dioecious Jioiv- 

 ers, mostly apetalous, sometimes achlamydeous (^occasionally polypetalous or 

 monopetalous) ; the ovary free and usually 3-celled, with a single or some- 

 times a pair of ovules hanging from, the summit of each cell ; stigmas or 

 branches of the style as many or twice as many as the cells ; fruit commonly 

 a 3-lobed pod, the lobes or carpels separating elastically from u, persistent 

 axis and elastically 2-valved ; seed anatropous ; embryo straight, almost as 

 long as and the flat cotyledons mostly as wide as the fleshy or oily albumen. 

 Stipules often present. — A vast family in the warmer parts of the world 

 (the acrid juice poisonous) ; most numerously represented in Northern 

 countries by the genus Euphorbia, which has very remarkable reduced 

 flowers enclosed in an involucre that imitates a calyx. Our last genus 

 belongs to the Box-Family, which some botanists of late separate from the 

 Euphorbiaceaj, on account of the rhaphe being on the outer or dorsal side 

 of the suspended ovule, &c. 



* Seeds and ovules only one in each cell, 

 .t- Staminate and pistillate flowers both destitute of calyx as well as corolla, and contained in 

 the same cup-shaped involucre, which imitates a calyx, — the whole liable to be mistaken 

 for a single flower. 



1. E^upllorbia. Involucre surrounding many staminate flowers (each of a single naked 



stamen) and one pistillate flower (a 3-lobed pistil). 



.t- ^ Statninate and pistillate flowers both with a calyx, not iovolucrate. 

 ++ Stamens erect in the bud. 



2. Jatroplia. Flowers cymose or panicled. Calyx coroUa^like, 5-cleft ; the lobes imbri- 



cated in the bud. Stamens 10 or more. 



3. Stlllln^ia. Flowers in a spike, pistillate at the base. Calyx 2- 3-parted, the lobes im- 



bricated in the bud. Stamens 2 or 3. Stigmas or branches of the style 3, simple. 



4. Acaly plia. Flowers spiked or glomerate, the pistillate in the axil of bracts. Calyx 3-5- 



parted ; in staminate flowers valvate in the bud. Stamens mostly 8 : anthers with 2 

 separate pendulous cells. Styles or stigmas 3, dissected. 

 6. Trngia. Flowers in racemes, pistillate at the base. Calyx in staminate flowers valvate in 

 the bud. Anther-cells united. Styles united at the base, simple. 

 +H- ++ Stamens infiexed in the bud. 



6. Croton, Flowers spiked or glomerate. Ovary and fruit 3- (rarely 2-4-) celled. 



7. Crotonopsts. Flowers scattered on the branchlets. Ovary and fruit 1-celled. 



* * Seeds and ovules 2 in each cell. Calyx imhricated in the bud. 



8. Pliyllnntlius, Flowers axillary. Stamens mostly 3, and usually monadelphous. 



9. Pachysandra. Flowers spiked. Calyx 4-parted. Stamens 4, separate. 



1. EUPHORBIA, L. Spdkge. 



Flowers monoecious, included in a cup-shaped 4 - 5-Iobed involucre {flower of 

 older authors) resembling a calyx or corolla, and usually bearing large thick 

 glands (with or without petal-like margins) at its sinuses. Sterile flowers 

 numerous and lining the base of the involucre, each from the axil of a little 

 bract, and consisting merely of a single stamen jointed on a pedicel like the fila- 

 ment : anther-cells globular, separate. Fertile flower solitary in the middle of 



