2 4 INTSODFOTOET ESSAY.
originated (PLATE I I , fig. la). The essential part of the inTolucrophore is a small
calyx, cup, cuplet or disk -which con-esponds to a spathel and is most usually sessile;
in several species, however, it is more or less narrowed to the base, as in G.
GriffitUanv,!! and 0. ZollingeriX (PLATE I I , figs. 6 - 8 0 ) or is even distinctly pedicellate.
The latter condition is very evident in C. symphysipus, 0. hcUracanthus and allied
species, in 0. exilû and allied species, and in 0. unifarius VAR. Pentong (PLATE II, fig.
l a ) . The pedicel of the involucrophore in the species mentioned clearly ueiuonstrate
the axial origin of the involucrophore.
The involucrophore is never absent from the female spikelets and presents
important diaguostie characters in its shape, and in its mode of insertion, whether sessile
or pedicelled, included in or oxserted from its own spathel, free from or partially
adnate to the spathel above its own. As the involucrophore represents a contracted
branchlet, or the axis of a rudimentary spikelet, emerging from the axil of its spathel,
i t reproduces the pecuUarities inherent in all the other divisions of the spadix and
just as at the insertion of the spikelets there is a specialized swelling or callus, which
I have supposed to be nectariferous, we find this same callus with its transverse cleft
or rima repeated in the axil of the involucrophore (PLATE II, fig. \i).
Within the involucrophore and usually moulded on this is the proper involucre of
the flower which corresponds exactly with the involucre of the male spikelets. Had
we made use of the term spathellule for the second appendicular organ of the male
snikelets we ought to have used this term also for the involucre of the female
spikelets and not for the involucrophore, a usage that must have led to confusion.
The involucre in female spikelets is mually concave and cupukr so as to admit
of the reception of the base of its flower ; its margin is truncate and usually entire,
but on the outer side it is more or less distinctly marked by two small teeth, between
which the mar.nn is more or less deeply Innately excised. Sometimes the involucre
is almost explanate and discoid or even appears as if made up of two bracts, which
in a few instances are almost separate, the apices of these bracts correspondmg with
the teeth of the involucre when it is cupular. On the involucre of the female flower
.Tternallv on a peculiarly shaped surface corresponding in position to the I - n . f.
efcavatioà of the margin, is invariably inserted a neuter flower (FLAT. I , figs. 8,
11c).
The small usually
inserted I have termed
usually lunar,ely shaped.
lunate
10,
sharply defined surface on which the neuter flower is
the " a r e o l a " of the neuter flower, This areola is most
somewhat depressed or developed move in breadth than in
W h t w ^ t ^ t h e hom¡'corresponding to the two marginal teeth. Sometimes, however,
i t is more developed vertically than horizontally and assumes a more or less ovate
or lanceolate shape as in C. Griffith- (PLATE II,^^
fig. 8c}, -or is more or
deerratus. The areola is not, however, alw
concave or subinvolucriform, as in C.
J depressed or linear, or its place is
sharply defined; in some cases it ii
fig. Ic) or by a punctiform scar. Sometimea
mariied by a small callosity (PLATE II
taken by a very short pedicel which supports the neuter flower, aa
too its place is
and G. Senryanus; this pedicel evidently represents there a second
iu (7. adtpersus
joint of
abortive
the small and contracted
spikelet from which tho fertile and the
spring. In G, Gmiingiamii
and C. nitidus tlie neuter flower has at its
THE FLOWERS. 25
base very small bracteoles of its own which may be taken as representing the
rudiments of a second involucre. The involucre of the female flower, as has been
already pointed out, is evidently formed by the coalescence of two appendicular organs
or bracteoles. Proof of this origin of the involucre is derived from the disposition
apd direction of its nerves, which converge to two opposite points on tho margin and
precisely to the two small horns qr teeth of the areola mentioned above. Moreover,
the nerve, which ought to correspond to the mesial costa of the bract, is often
prominent and forms a keel so that the floral involucre besides being bidentate is
often even 2-keeled on tho side next to the axis.
In some few instances two fertile flowers originate from each spathel, as in
C. fertilis, C. didymocarpus, C. paahystachys, C. siamensis and occasionally also in
C. decrraius. In C. /eriiiis at each spathel a single involucrophore bears two cupular
involucres of equal size and similar shape (PLATE 230, fig. 5), and each involucre
bears its own sterile flower; tho same condition occurs occasionally in G. didymocarpus
(PLATE I I , fig. -3). In the other species mentioned the second fertile flower arises
from what ought to have been the areola of the neuter flower and in this cose the
areola itself is larger, deeper and subcupular.
In the female spikelets each female flower is accompanied by a sterile one; when,
therefore, as in G. tenuis this is highly developed, the spikelets, immediately prior
to the opening of the flowers, display two distinct scries of fertile and two of sterile
flowers, or four series in all. C. siamensis, which has two fei-tile flowers to each
spatbel, has therefore four series of fertile flowers, and as each pair of fertile flowers
is accompanied by one rather distinct neuter flower, the total number of series of
flowers is six. Finally in G. ferlilis, where each of the two flowers belonging to
each spathel is accompanied by a sterile one the total number of series of flowers
is eight.
XV.-The Flon-ers,
I have already explained how in the male spikelets the flowers arise from or
near the axil of every spathel and how thoy are arranged right and left in two
longitudinal series, these being in one plane or being more or less assurgent.
I have also pointed out that in the male spikelets the flowers are solitary on
each spikelet, and that in only a few cases ( G. viminalis, G. pseudo-tsnuis ) in place of
a single flower there is a glomerule of flowers representing a contracted secondary
spikelet.
The bifarious arrangement of the flowers on one plane is the most usual, and
in this case the spikelets arc broad, flat and straight or slightly curved; in several
species however the spikelets assume a scorpioid tendency, because the two series of
flowers are assurgent and point upwards and are secundly arranged as in the
scorpioid cyme of a Meliotropium; this arrangement obtains in species of the groups
of G. exilia, of C. Meracanthcs and of G. Euegelianus.
In the female spikelets also a solitary female flower usually arises from each
spathel, but this is accompanied by a neuter flower. If this be of large size and
long persistent, the spikelets appear to have four series of flowers, as in G. tenuis,
€. javensis, etc,; but when the neuter flowers are very small, and after the neuter
flowers fall, the female spikelets also appear (0 have biseriate • flowers. For the
AMN. EÛT, BOT. GAKD, CALCUTTA VOL. X I .