84 
THE AMERICAN BOTANIST. 
transformed into petal-like organs are usually present. In the 
Orchidales, however, the reduction is even more complete, for 
often no trace of the missing stamens are to be found. Aside 
from these differences the chief thing that distinguishes the 
Orchidales from their nearest of kin is the character of the 
seed, orchid seeds, as many may remember are extremely small 
and light, in fact the smallest seeds in the world are found 
among these plants. Not only are they small, but they are 
very poorly developed and do not show the compact and 
differentiated embryo common to the highest types of Dicoty- 
ledons. The embryo consists of but a few cells in which the 
cotyledon and plumule are not distinguishable and this in en- 
closed in a remarkably loose thin seed coat. Because of the 
small size of the seeds, the Orchidales are often called in old 
books the Microspermae. In most of the species the seeds are 
without albumen, but this character, according to Rendle does 
not hold throughout the group. 
The orchid flower is noted for the variation in form pre- 
sented, and yet so unvarying is the fundamental structure 
that nearly all of the six thousand species are placed in one 
great family the Orchidaceae. It might puzzle even a good 
botanist to name the other family that with the Orchidaceae 
forms the Orchidales. Nor would he, unless familiar with 
tropical plants, be likely to recognize species of this other 
family or to imagine them near of kin to the orchids for curi- 
ously enough most of them have actinomorphic or regular 
flowers. It seem an anomaly to group plants with regular 
flowers among the orchids, but the character of the seeds in 
both families makes it necessary. This second family is the 
Burmanniaceae. Most of its sixty species are leafless sapro- 
phytes living in the decaying vegetation on the floor of tropi- 
cal forests. A few are gren plants living in savannas and two 
species extend far enough north in the United States to get 
mentioned in our Northern manuals. Some of the Burman- 
