ELEMENTARY BOTANY. 
XI 
the same point and are nearly of the same length. It differs from the head, like 
the raceme from the spike, in that the flowers are not sessile. An umbel is said to 
be simple, when each of its branches or rays bears a single flower ; compound when 
each ray bears a partial umbel or umbellule. 
a Corymb, or corymbose , when the branches and pedicels, although starting from 
different points, all attain the same level, the lower ones being much longer than 
the upper. It is a flat-topped or fastigiate panicle. 
a Cyme , or cymose, when branched and centrifugal. It is a centrifugal panicle, 
and is often corymbose. The central flower opens first. The lateral branches succes- 
sively developed are usually forked or opposite (dichotomous or trichotomous), but 
sometimes after the first forking the branches are no longer divided, but produce a 
succession of pedicels on their upper side, forming apparently unilateral centripetal 
racemes ; whereas if attentively examined, it will be found that each pedicel is at 
first terminal, but becomes lateral by the development of one outer branch only, 
immediately under the pedicel. Such branches, when in bud, are generally rolled 
back at the top, like the tail of a scorpion, and are thence called scorpioid. 
a Thyrsus , or thyrsoid , when cymes, usually opposite, are arranged in a narrow 
pyramidal panicle. 
75. There are numerous cases where inflorescences are intermediate between some 
two of the above, and are called by different botanists by one or the other name ac- 
cording as they are guided by apparent or by theoretical similarity. A spike-like 
panicle, where the axis is divided into very short branches forming a cylindrical 
compact inflorescence, is called sometimes a spike, sometimes a panicle. If the flowers 
are in distinct clusters along a simple axis, the inflorescence is described as an inter- 
rupted spike or raceme, according as the flowers are nearly sessile or distinctly pedicel- 
late ; although when closely examined the flowers will be found to be inserted not on 
the main axis, but on a very short branch, thus, strictly speaking, constituting a 
panicle. 
76. The catkins [amenta) of Amentacece, the spadices of several Monocotyledons, 
the ears and spikelets of Grasses are forms of the spike. 
77. Bracts are generally placed singly under each branch of the inflorescence, and 
under each pedicel ; bracteoles are usually two, one on each side, on the pedicel or 
close under the flower, or even upon the calyx itself ; but bracts are also frequently 
scattered along the branches without axillary pedicels ; and when the differences 
between the bracts and bracteoles are trifling or immaterial, they are usually all 
called bracts. 
78. When these bracts appear to proceed from the same point, they will, on ex- 
amination, be found to be really either one bract and two stipules, or one bract with 
two bracteoles in its axil. When two bracts appear to proceed from the same point, 
they will usually be found to be the stipules of an undeveloped bract, unless the 
branches of the inflorescence are opposite, when the bracts will of course be oppo- 
site also. 
79. When several bracts are collected in a whorl, or are so close together as to 
appear whorled, or are closely imbricated round the base of a head or umbel, they 
are collectively called an Involucre . The bracts composing an involucre are described 
under the names of leaves , leaflets, bracts , or scales , according to their appearance. 
Phyllaries is a useless term, lately introduced for the bracts or scales of the invo- 
lucre of Compositce. An Involucel is the involucre of a partial umbel. 
80. When several very small bracts are placed round the base of a calyx or of an 
involucre, they have been termed a calycule, and the calyx or involucre said to be 
calyculate , but these terms are now falling into disuse, as conveying a false im- 
pression. When the bracts are whorled and inserted upon the calyx, they form 
what is frequently called an epicalyx. 
81. A Spatha is a bract or floral leaf enclosing the inflorescence of some Monoco- 
tyledons. 
82. Palece, pales, or Chaff, are the inner bracts or scales in’ Composite , Graminece, 
and some other plants, when of a t hin yet stiff consistence, usually narrow and 
of a pale colour. 
83. Glumes are the bracts enclosing the flowers of Ctjperacece and Graminece. 
