Missouri Botanical 
Garden Bulletin 
Vol.V —— St. Louis, Mo., November, 1917 No. 11 
THE POINSETTIA 
The poinsettia (Euphorbia pulcherrima), otherwise 
known as the Christmas flower or Mexican flame-leaf, is one 
of the few plants belonging to the Euphorbiaceae that is 
cultivated commercially for ornamental purposes. The 
flowers are insignificant, but the brilliant bracts upon which 
they rest possess such an intensity of color and are so large 
that the effect produced is scarcely equaled by any other 
lant under cultivation. Since its introduction from Mex- 
1¢0, in 1834, the poinsettia has become much used for decora- 
tion at Christmas, its popularity being enhanced by the fact 
that even after the lower green leaves drop off the bracts 
remain for a long period. 
The plant is a shrub 2-10 feet in height, found in most 
shaded parts of tropical Mexico and Central America. The 
lower leaves are green, ovate-elliptical, toothed or lobed, and 
prominently veined. The upper leaves or bracts are nar- 
rower and vermilion-red in color. The flowers are greenish 
with large yellow glands. In 1873 M. Benedict Roezl dis- 
covered in a small Indian village in the state of Guerrero, 
Mexico, a double form, Euphorbia pulcherrima var. plenis- 
sima. This new form is remarkable for its size—the head 
of the bracts reaching 18 inches across and 11 inches in 
depth—, its distinct satiation, and its marvelous brilliancy. 
The central cyme of flowers is surmounted by bracts from 
which other flowers develop on short, simple stems, each sur- 
mounted by bracts and flowers. The secondary heads be- 
come further subdivided, culminating in a mass of red. 
Often many of the flowers are converted into bracts, as man 
as 50 having been observed on a single stem. : 
The possibility of newer development in the poinsettia 
has been shown by the crossing of Euphorbia pulcherrima 
and E. lutescens, with the resultant E. salmonea var. Adneti. 
Euphorbia lutescens is similar to E. pulcherrima but differs 
in the color of its bracts, which are greenish white, and the 
more vigorous and abundant foliage. The hybrid, known 
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