EUPHOEBIACE^E. 727 



LXVL SPURGE FAMILY. EUPHORBIACE.E. 



Herbs, shrubs, or trees, much varied in foliage and inflorescence. 

 Flowers always unisexual, with or without a perianth. Stamens 

 various. Ovary consisting of 3 (rarely 2 or more than 3) united 

 carpels, each with 1 or 2 pendulous ovules. Styles as many as 

 carpels, entire or divided. In the fruit these carpels separate 

 from each other and from the persistent axis, and usually open with 

 elasticity in two valves. Seed with a large embryo in fleshy al- 

 bumen. 



A vast family, chiefly tropical, so varied in aspect that no general 

 idea can be formed of it from the three genera which represent it in 

 Britain, nor is the connection between these three genera easily under- 

 stood without a comparison with intermediate exotic forms. The 

 structure of the ovary and fruit is peculiar to this family amongst uni- 

 sexual plants. 



Several male flowers (looking like single stamens) and one 

 stalked ovary collected in a small involucre, which has 



the appearance of a cup-shaped perianth 1. Spurge. 



Male and female flowers distinct. 



Herbs, with thin leaves .2. Mercury. 



Shrubs, with shining, evergreen leaves ....... 3. Box. 



The Poinsettia of our hothouses, remarkable for its brilliant red 

 bracts, belongs to this family, but generally speaking the tropical 

 JZupJiorbiacece are not ornamental enough for cultivation. 



I. SPURGE. EUPHOKBIA. 



The European species are herbs, abounding in milky juice ; the 

 lower part of the stems simple, with alternate leaves (except in the 

 caper S.). Flowering branches or peduncles axillary, the upper ones 

 in a terminal umbel of 2 to 5 or more rays, each ray or axillary pe- 

 duncle usually several times forked, with a pair of opposite floral leaves 

 at each fork, and a small green, apparent flower, really a head of 

 flowers between the branches. These Jlower- heads consist of a small, 

 cup-shaped involucre (looking like a perianth), with 4 or 5 very small 

 teeth, alternating with as many horizontal yellowish or brown glands. 

 Within are 10 to 15 stamens, each with a jointed filament, and a mi- 

 nute scale at its base, showing that they are each a distinct male 

 flower. In the centre is a single female flower, consisting of a 3-celled 

 ovary, supported on a stalk projecting from the involucre and curved 

 downwards. Style 3-cleft. Fruit of 3 carpels, each with a single seed. 



