PARH AND CEMETERY 
117 
GARDEN PLANTS-THEIR GEOGRAPHY— LXVIIL 
EUPHORBIALES. 
The Euphorbia, Buxus and Croton Alliance. 
The “Unisexuales” are too numerous and diverse 
for a manageable garden group. I therefore divide 
them into three, using the well known names, Euphor- 
biales, Urticales and Quernales to distinguish them. 
EUPHORBIA PULCHERRIMA 
Euphorbiales have six tribes, 212 genera and 3,000 
species. 
Botanically, the group has been considerably en- 
tangled with others. One set of men think it is poly- 
petalous and give it various names. Another, more 
reasonable I think, consider it apetalous with a tend- 
ency to form petals ; and why should not nature intro- 
duce petals in any group? Why not as well as suc- 
culency for instance. As a matter of fact she does 
such things and laughs at the apetalous conceits of 
humanity, even though they are more convenient than 
Choripetalous ones. Should it ever be possible to 
search the tropics for abnormal forms, many people will 
be at their wits end for descriptive terms ; a consum- 
mation not altogether undesirable. Nature will ridi- 
cule them in every square mile. 
The general physiology of the Euphorbia group has 
considerable uniformity, Choripetalae notwithstanding. 
They are unisexual, they usually have consolidated 
pistils and tricoccous fruit. In habit they are some- 
times large trees, but more frequently small trees or 
shrubs. In Africa and India they often become suc- 
culents mimicking Cereus, while in cold temperate re- 
gions they are mostly herbs. Very few are climbers. 
They often abound in venomous milky juice. Sev- 
eral have stinging properties. The bark, leaves and 
seeds of many are medicinal. Hippomane mancinella, 
Excaecaria, Agallocha, Hura crepitans, Sapium au- 
cuparium and others are dangerous. Hevea Guian- 
ensis and its varieties are the Para rubber trees. 
Manihot utilissima is full of iioisonous acrid juice in 
the raw state, but the roots, after rasping, washing and 
heating, produce the highly farinaceous tapioca. The 
group abounds with useful plants. In warm regions a 
large proportion of the species and their varieties are 
highly ornamental in flower, foliage or form. In the 
cold regions, however, these gradually become fewer 
and fewer. 
Euphorbia has 635 or more species in tropical, 
sub-tropical and temperate regions. E. pulcherrima 
is distinguished by its gorgeous crimson involucres 
which, in suitable climates, become expansive as som- 
breros. It is now grown all over the tropics, but does 
best within those latitudes at elevations of from 3,000 
to 6,000 feet. It is a native of Mexico and was intro- 
duced to cultivation in the states by Dr. Poinsett, of 
Charleston, S. C., and called E. Poinsettiana in his 
honor, by the late Robert Buist, a famous Scotch 
plantsman, resident at Philadelphia. By him it was 
sent to Europe, and there erected into a distinct genus 
by botanists, who thus confused the nomenclature. 
Now “Poinsettia” is a section of Euphorbia. There is 
a double form, and a creamy white variety. They do 
well in southern California. E. heterophylla, found 
from Iowa and Missouri southwestward, belongs the 
same section. It is treated as a tender annual north- 
ward, but scarcely perfects its partly red leaves before 
frost. Several other tender species of the Poinsettia 
section are worthy attention. E. splendens and E. 
JATROPHA STIMULOSA. 
