WEATHERWAX: MORPHOLOGY OF FLOWERS OF ZEA MAys' 129 
STAMINATE FLOWER 
The male spikelet contains, either functional or in rudimen- 
tary form, all the parts of the typical grass spikelet. It is normally 
two-flowered. A few one-flowered spikelets have been observed, 
but they usually contain a second flower in an undeveloped 
condition. At the ends of rachids, spikelets with more than two 
flowers are sometimes found, but they are probably to be under- 
stood as being two or more two-flowered spikelets combined. 
Completely enclosing the rest of the 
spikelet. before maturity are the two 
rather firm, taper-pointed, empty glu- 
mes, having a varying number of nerves 
and thickly beset, as is the rachilla be- 
low the glumes, with short, stiff bristles. 
The lower glume overlaps the edges of 
the upper and has the lower point of 
insertion upon the rachilla (Fic. 1). The Nae 3. Peaeeyate OS 
flower is in the axis of the thin, mem= a ce 
branaceous, blunt-pointed, two- to four- en 8 aia msi 
nerved lemma or flowering glume, and 
subtended by the palea, which hes ’ ther; L, lemma; P, rudimen- 
similar structure except that it is reg- tary pistil; Pa, palea. 
ularly two-nerved. No trace of a con- 
tinuation of the rachilla has been observed between the paleae. 
On this basis, then, there is no indication that the normal spike- 
The rachilla is jointed 
let was ever more than two-flowered. 
just below the glumes. 
In so far as was observed, the two flowers are identical in 
structure, but the upper one is the first to mature. During micro- 
spore development the anthers of the upper flower are often found 
with the tetrad stage or with the pollen grains rounded off, while 
those of the lower flower show resting or synaptic stages; but the 
pollen grains of the younger flowers are usually rounded off and 
apparently mature before the older flower puts out its stamens. 
The three stamens of each flower are so arranged that their 
points of attachment form the vertices of a triangle which has 
one of its bases toward the palea. Midway between the :two 
lateral stamens is the rudiment of a pistil. Next to the lemma, 
