OUTLINES OP BOTANY. ix 



an £7mfccl, or umbellate, when several branches or pedicels appear to start from 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 ot 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 successively 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 oases where infiorescenees are intermediate between some two of the 

 above, and are called by different botanists by one or the other name, according 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 interrupted spike or raceme, according as the flowers are nearly 

 sessile or distinctly pedicellate ; 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 Amentaeece, 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 ; braoteoles 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 three bracts appear to proceed from the same point, they will, on examination, be 

 found to be really either one bract and two stipules, or one bract with two bracteoles in its axils. 

 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 opposite 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. Fhyllaries is a useless term, lately introduced 

 for the bracts or scales of the involucre of Compositm. 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 impression. 



81. A Spatha is a bract or floral leaf enclosing the inflorescence of some Monocotyledons. 



82. PaletE, Pales, or Chaff are the inner bracts or scales in Compositee, Qramine<B, and some 

 other plants, when of a thin yet stiff consistence, usually narrow and of a pale colour. 



83. Glumes are the bracts enclosing the flowers of Gyperacene and Graminea. 



§ 8. The Flower in General. 



84. A complete Flower (15) is one in which the calyx, corolla, stamens, and pistils are all 

 present ; a perfect flower, one in which all these organs, or such of them as are present, are 

 capable of performing their several functions. Therefore, properly speaking, an incomplete 

 flower is one in which any one or more of these organs is wanting ; and an imperfect flower, one 

 in which any one or more of these organs is so altered as to be incapable of properly performing 

 its functions. These imperfect organs are said to be abortive if much reduced in size or 

 efficiency, rudimentary if so much so as to be scarcely perceptible. But, in many workjS, the term 

 incomplete is specially applied to those flowers in which the perianth is simple or wanting, and 

 imperfect to those in which either the stamens or pistils are imperfect or wanting. 



85. A Flower is 



dichlamydemis, when the perianth is double, both calyx and corolla being present and 

 distinct. 



monochlamydeous, when the perianth is single, whether by the union of the calyx and 

 corolla, or the deficiency of either. 



