THE LEAVES. 9 
A complete Calamus leaf is made up of a basilar portion or sheath, which usually 
takes the form of a. tube completely enclosing each joint or internode, and of the 
leaf proper. Within the latter we have to distinguish a medium portion or rib 
known as the rachis, and to right and left of the rachis the leaflets, which vary 
in number according to the species. The first or lower portion of the rachis which 
usually is destitute of leaflets may be held to represent the petiole. Then in 
whole groups of species the rachis is prolonged beyond the distal leaflets as a long 
and slender whip-like clawed appendage termed the cirrus. 
The leaves of an adult Calamus plant are always pinnate except in the cases 
of C. flabellatus, where they are furcate-flabellate, in that of C. radiatus where they 
are digitate-radiate and in those of C. digitatus and C. pachystemonus where we 
find only 2—4 leaflets approximated at the apex of the petiole. These three kinds 
of leaves, however, are, it is to be noted, kinds that first appear after the 
germination of the seed, even in those species that ultimately have regularly pinnate 
leaves in the higher part of the plant. 
On account of the diversity of form assumed by the leaves in Calamus it is 
therefore most important to know when describing them whether they be leaves 
from the lower or leaves from the upper part of the plant, because the differences 
between leaves from these two situations are often very remarkable. I have 
therefore in these descriptions of Calami, unless it is otherwise stated, always record- 
ed the characters of the leaves of the adult plant. 
In the measurements given by me of the leaves of Calamus it is to be noted 
that I include in the leaf that portion of the rachis which has no leaflets and 
which is usually spoken of as the petiole. But the sheath is not included nor 
is the terminal cirrus, when a cirrus is present ; ; 8o that the length of the leaves 
is measured along the rachis from its junction with the sheath to the point of 
attachment of the uppermost leaflets. 
As the first leaves in a very young plant of Calamus are flabellate, furcate, 
radiate or digitate, we may conclude that the pinnate leaves of the full grown plant 
are derivates of these simpler forms and consider C. digitatus, C. pachystemonus, C, 
radiatus and C. flabellatus as survivals of the primitive types of the genus. 
The cirrus is often very long and is always armed with “claws.” These 
claws, as we have already seen in discussing them generally, are sometimes solitary, 
but are more frequently 3-nate or 5-nate-digitate, especially towards the tip of the 
cirrus and in more robust cirri are even 7-nate and arranged in 4—3 whorls 
with more or less uniform naked intervals between the groups of claws, In 
appearance and in function the cirrus corresponds exactly to the leaf-sheath flagel- 
lum, to be discussed further on: in origin, however, it is altogether different. 
| In cirriferous leaves the leaflets attached along both sides of the rachis may 
either cease abruptly at a definite point or may gradually decrease in size upwards. 
The leaves of the lower part of the stem and the radical leaves are non- 
cirriferous, and often end in two more or less confluent leaflets or in  bifurcate 
leaflets even in species where the leaves in the higher p of the — 
normally have a typical cirrus. 
Axx, Roy, Bor. Gano, Catcutra, Vou, XI, 
