98 



STAMENS. 



[SECTION 9. 



it, while its other edge is covered by the next behind it. The oilier mode 

 is the 



Imbricate or Imbricatpd, in Aviiicli tlie outer parts cover or overlap the 

 inner so as to "break joints," like tiles 

 or shingles on a roof ; whence the name. 

 When the parts ave three, the first or jl 

 outermost is wholly external, the third 

 wholly internal, the second has one 

 margin covered by the first while the 

 other overlaps the third or innermost 

 piece : this is the arrangement of alternate three- 

 ranked leaves (187). When there are five pieces, as in the corolla of Fig. 

 225, and calyx of Fig. 281, as also of Fig. 241, 276, two are external, 

 two are internal, and one (the third in the spiral) has one edge covered 

 by the outermost, while its other edge covers the in- 

 nermost; which is just the five-ranked arrangement of 

 alternate leaves (1S8). When the pieces are four, two 

 arc outer and two are inner; which answers to the ar- 

 rangement of opposite leaves. 



279. The imbricate and the convolute modes some- 

 times vary one into the other, especially in the corolla. 



?80. In a gamopetalous corolla or gamosepalous calyx, 

 the shape of the tube in the bud may sometimes be notice- 

 able. It may be 



Plicate or Plaited, that is, folded lengthwise ; and the 

 plaits may either be turned outwards, forming projecting 

 ridges, as in the corolla of Campanula; or turned in- 

 wards, as in that of Gentian Belladonna ; or 



Supervolute, when the plaits are convolutely wrapped 

 round each other, as in the corolla of Morning Glory and of Stramonium, 

 Fi^. 282. 



Section IX. STAMENS IN PARTICULAR. 



281. Androecium is a technical name for the staminate system of a 

 flower (that is, for the stamens taken together), which it is sometimes con- 

 venient to use. The preceding section has dealt with modifications of the 

 flower pertaining mainly to calyx and corolla. Those relating to the sta- 

 mens are now to be indicated. First as to 



Fig. 280. Convolute aestivation, as in the corolla-lobes of Oleander. 



Fio. 281. Diagram of a Fla.x-flower ; calyx imbricated and corolla convolute in 

 the bud. 



Fig. 282. Upper part of corolla of Datura Stramonium in the bud ; and below 

 a section showing the convolution of the plaits. 



