INTEODtTCTlOK, 11" 



attain the same level, giving the inflorescence the appearance of an umbrella. 

 The pedicels are then called the rays of the umbel. A compound umbel is 

 one in vrhich each ray bears an umbel of flowers (called an umhellule) in- 

 stead of a single flower. 



A Corymb, or corymbose inflorescence, is a flat-topped panicle. The 

 branches, although startmg from different points, all attain the same level, 

 the lower ones being much longer than the central ones. 



A Cyme, or cymose inflorescence, is a centrifugal panicle, and generally 

 assumes the corymbose form. The central flower opens first. The lateral 

 branches successively developed are usually forked or opposite (dichotomous 

 or trichotomous), but sometimes after the first foridng the branches are no 

 longer divided, but produce a succession of pedicels on the upper side, form- 

 ing apparently unilateral centripetal racemes ; whereas, if attentively exa- 

 mined, it will be found that each pedicel is really terminal, but that only one 

 branch on the outer side is developed immediately luider the pedicel. Such 

 branches when in bud are generally roUed back at the top like the tail of a 

 scorpion, and are therefore called scorpioid. 



There are numerous cases where inflorescences are intennediate 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 theoretical simi- 

 larity. A spike-like panicle where the axis is divided into very short branches 

 forming a cylmch-ical compact inflorescence, is called sometimes a spike, 

 sometimes a panicle. If the flowers are in distLuct clusters along a simple 

 axis, tlie inflorescence is described as an interrupted spike, or raceme, ac- 

 cording as the flowers are nearly sessUe, or distinctly pedicellate ; although, 

 when closely examined, the flowers or pedicels will be found to be inserted, 

 not on the main axis, but on a very short branch, thus, strictly speaking, 

 constituting a panicle. 



The catkins of tlie AmentacecB, or Catkin family, the spadices of several 

 Monocotyledons are forms of the spike. 



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 tr iflin g or 

 immaterial, they are usually all called bracts. 



When three bracts appear to proceed from the same point, they will, on 

 examiuation, be found to be really one bract and its two stipules ; or, if im- 

 mediately under a flower or pedicel, one bract and 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 tlie bracts will of course be opposite also. 



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 

 unbel, they are collectively called an Involucre. The bracts composing an 

 involucre are described under the name of leaves, leaflets, bracts, or scales, 

 according to their appearance. Phyllaries is a very useless term, lately in- 

 troduced, for the bracts or scales of the involucre of Composites. 



A Spatha is a bract or floral leaf enclosing the inflorescence of some Mono- 

 cotyledons. 



PakcB, Pales, or Chaff, are the inner bracts or scales in Composites, 

 Grasses, and some other plants, when of a thin yet stiff" consistence, usually 

 narrow and of a pale colour. 



