OUTLINES OF BOTANY. XXI X 



the two or three lower ones or under lip. In Orchidem and some other 

 families the name of lip, or labellum, is given to one of the divisions or 

 lobes of the perianth. 



personate, when two-lipped, and the orifice of the tube closed by a 

 projection from the base of the upper or lower lip, called a palate. 



ringent, when very strongly two-lipped, and the orifice of the tube 

 very open. 



spurred, when the tube or the lower part of a petal has a conical 

 hollow projection, compared to the spur of a cock; saccate, when the spur 

 is short and round like a little bag; gibbous, when projecting at any part 

 into a slight swelling. 



resupinate or reversed, when a lip, spur, etc., which in allied species 

 is usually lowest, lies uppermost, and vice versd. 



106. The above terms are mostly applied to the forms of monopetalous 

 corollas, but several are also applicable to those of polypetalous ones. 

 Terms descriptive of the special forms of corolla in certain Natural Orders, 

 will be explained under those Orders respectively. 



107. Most of the terms used for describing the forms of leaves (39, 45) 

 are also applicable to those of individual petals ; but the flat expanded por- 

 tion of a petal, corresponding to the blade of the leaf, is called its lamina, 

 and the stalk, corresponding to the petiole, its claw (unguis). The stalked 

 petal is said to be unguiculate. 



§ 10. The Stamens. 



108. Although in a few cases the outer stamens may gradually pass into 

 petals, yet, in general, Stamens are very different in shape and aspect 

 from leaves, sepals, or petals. It is only in a theoretical point of view (not 

 the less important in the study of the physiological economy of the plant) 

 that they can be called altered leaves. 



109. This usual form is a stalk, called the filament, bearing at the top 

 an anther divided into two pouches or cells. These anther-cells are filled 

 with pollen, consisting of minute grains, usually forming a yellow dust, 

 which, when the flower expands, is scattered from an opening in each cell. 

 When the two cells are not closely contiguous, the portion of the anther 

 that unites them is called the convectivum. 



110. The filament is often wanting, and the anther sessile, yet still the 

 stamen is perfect; but if the anther, which is the essential part of the sta- 

 men, is wanting, or does not contain pollen, the stamen is imperfect, and is 

 then said to be barren or sterile (without pollen), abortive or rudimentary 

 (84), according to the degree to which the imperfection is carried. Imper- 

 fect stamens are often called staminodia. 



111. In unsymmetrical flowers, the stamens of each whorl are some- 

 times reduced in number below that of the petals, even to a single one, and 

 in several Natural Orders they are multiplied indefinitely. 



112. The terms monandrous and polyandrous are restricted to flowers 

 which have really but one stamen, or an indefinite number respectively. 

 Where several stamens are united into one, the flower is said to be synan- 

 drous. 



113. Stamens are 



monadelphous, when united by their filaments into one cluster. This 

 cluster either forms a tube round the pistil, or, if the pistil is wanting, 

 occupies the centre of the flowe*. 



