BULLETIN 1127, U. S. DEPARTMENT OF AGRICULTURE. 
The inflorescence is a panicle, the main axis of which is smooth, 
except toward the apex, where it often is slightly rough. The 
branches are arranged singly or in pairs and have a somewhat rough 
surface. The panicle is compact and drooping (Fig. 3), though 
sometimes it is erect and open. 
The spikelets (PI. I, A) are 1-flowered and strongly compressed 
laterally. There are two small lance-shaped glumes (PI. I, A 1). 
These are keeled or flat and are about one- 
third as long as the lemma and palea. They 
often have a sharp tooth on one or both of 
their margins below the apex. In some vari- 
eties the glumes are much longer and very 
conspicuous. The lemma (PI. I, A, 2) and 
palea (PI. I, A, 3) are firm chartaceous, 
usually pubescent, and strongly compressed 
laterally. They are of the same length and 
keeled. The lemma has five nerves and often 
is awned. Its margins are curved inward, 
clasping the outcurved margins of the palea. 
The palea has two nerves, which are located 
very near the margins. The lateral and cen- 
tral nerves of the lemma and the two nerves 
of the palea sometimes are excurrent as short 
conical teeth (PI. I, B, 4), which are often 
conspicuous by their color. 
The flower of the rice plant is inclosed 
within the lemma and palea. It consists of 
six stamens and a comparatively long ovary 
surmounted by two styles united at their 
bases and each bearing a plumose stigma. 
There also are two loclicules. 
In the popular sense, the seed (PL I, B) 
of the rice plant consists of the glumes, 
lemma, palea, and kernel. Commercially, 
the terms rough rice and paddy are used to 
designate this thrashed grain when marketed 
for milling. The lemma and palea consti- 
tute the hull (PL I, B, 2 and 3), which 
incloses the kernel. 
The kernel (PL I, 0) or caryopsis is com- 
pletely inclosed by the lemma and palea. It 
may be oblong, elliptical, or almost ovoid in 
shape. Its width (lateral diameter) is 
never greater than its thickness (dorsiven- 
tral diameter). The surface of the kernel is marked on each side 
by two longitudinal ridges and one deep groove (PL I, 0,6). The 
grooves lie near the ventral margin and are conspicuous. The 
embryo (PL I, O, 1) is located on the dorsal surface and lies 
obliquely to the long axis of the kernel. In the short-grain varieties 
it is approximately one-third as long as the kernel; in the long- 
grain rices one-fourth as long. The endosperm is white, hard, and 
flinty, though sometimes soft and brittle. It is translucent, but of- 
ten has a white opaque area (PL 1,0,2) within. This may be located 
BB»B 
i 
■;, f 
ffl 
Fig. 2. — A part of two in- 
ternodes of a culm of 
rice, showing ligule (A), 
auricle (B), leaf sheaths 
(C) and (E), and leaf 
blade (D). (Natural 
size.) 
