E UPHORBIA CEAE 
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really bracts, and between these are 4 curious horn-like bodies 
(U-shaped in fig.), which are the combined stipules of the bracts. Then 
follow a number of sta. arranged with the 
oldest nearest to the centre and each with a 
peculiar joint half-way up the stalk. In the 
middle of the cyathium is a 3-carpelled 
ovary on a long stalk. This is usually ripe 
for pollination before any of the sta. ripen. 
That this cyathium is an infl. and not 
a fir., consisting of a lot of c? firs., each of 
1 sta., round a single ? fir., is shown by 
several facts, eg. the centrifugal (cymose) 
order of ripening of the organs, and the 
joint on the sta.; at this point in the 
allied genus Anthostema, there is a peri- 
anth, Vyhich shows that the sta. is really a 
reduced S fir. 
In E. § Poinsettia the infl. is rendered conspicuous by the bright 
red colour of the larger upper bracts. These sp. are often cultivated 
as showy conservatory plants. 
The fruit explodes when ripe; the carpels split off from the central 
axis and open at the same moment. 
Euphorbiaceae. Dicotyledons (Archichl. Geraniales). 220 gen. with 
4000 sp., cosmop., except in the arctic regions. Few sp. have a very 
wide range; the most widely-ranging genus is Euphorbia itself. 
Benth. -Hooker place E. in Incompletae, but it is closely related to 
Geraniales by the structure of the gynoeceum, &c., although separated 
a good deal from the other orders of the cohort by the amount of 
reduction that has occurred in most of its firs. 
Most E. are shrubs or trees, a few herbaceous [e.g. the Brit. sp.). 
Many are xerophytes; a number of Australian sp. are of ericoid habit 
(p. 166); the S. Afr. sp. of Euphorbia are cactus-like; others 
resemble Lauraceae, or possess phylloclades [eg. Phyllanthus sp.). 
A few are lianes. The leaves are usually alternate ; some have 
opposite leaves, some opposite leaves above and alternate below. 
Stipules are usually present, but may be represented by branched 
hair-like bodies (Jatropha), glands, or thorns. Nearly all E. contain 
latex in special laticiferous cells. 
The infl. is usually complex ; almost every type occurs. Often 
the first branching is racemose and all subsequent ones cymose. In 
some cases, eg. Dalechampia and Euphorbia (^.z/.), the partial infls. 
are so condensed as to give the appearance of single firs. The firs, are 
always unisexual, monoecious or dioecious, regular, hypogynous. The 
perianth may be present as two whorls ; more often there is only one 
(calyx) and frequently the fir. is naked. The perianth is usually 
5-merous. Sta. 1 — 00, free or united in various ways. Ricinus has 
Diagram of central cya- 
thium of infl. of E uphorbia 
Peplus L. (after Eichler, 
modified). 
