196 



FLORAL ENVELOPES — CALYX. 



and tpdXKov, a leaf). These calycine leaves are sometimes separate 

 from each other, at other times they are united to a greater or less ex- 

 tent; in the former case, the calyx is dialysepalous (^diaXveiv, to divide), 

 polysepalous or polyphyllous ('iroXug, many) ; in the latter, gamosepalous 

 or gamophyllous, monosepalous or monophyllous (ya/ios, union, //,6«o;, 

 one). The divisions of the calyx present usually all the characters of 

 leaves, and in some cases of monstrosity they are converted into the 

 ordinary leaves of the plant. This is frequently seen in the Rose 

 (fig. 24-7 c, p. 172), Pseony, etc. Their structure consists of cellular 

 tissue or parenchyma, traversed by vascular bundles, in the form of 

 ribs and veins, containing spiral vessels, which can be unrolled, deli- 

 cate woody fibres, and other vessels, — the whole being enclosed in an 

 epidermal covering, having stomata and often hairs on its outer sur- 

 face, which corresponds to the under side of the leaf. 



In the great divisions of the vegetable kingdom, the venation of 

 the calyx is similar to that of the leaves ; parallel in Monocotyledons, 

 reticulated in Dicotyledons. The leaves of the calyx are usually 

 entire (fig. 293), but occasionally they are cut in various ways, as in 

 the Rose (fig. 294 cf), and they are sometimes hooked at the margin, 

 as in Rumex uncatus (fig. 295 ci). In the last-named plant there 



Fig. 293. 



Fig. 294. 



Fig. 295. 



are two whorls of calycine leaves, the outer of which, ce, are entire, 

 while the sepals of the inner whorl have hooked margins and have 

 also swellings, g, in the form of grains or tubercles on the back. The 

 outer leaves, ce, may be looked upon in this case as bracts, occupying 

 an intermediate place between leaves and sepals. It is rare to find 



Fig. 293. Peiitaphyllous or pentasepalous calyx of Stellaria Holostea ; sepals entire. 

 Fig. 294. Flower of Eose, cut vertically, et, Tube of the calyic cf, Limb of calyx 

 divided into leaflets, e e, Stamens, o o, Ovaries, each having a style which reaches beyond 

 the tube of the calyx, and ends in a stigma, s. r, Receptacle. Fig. 295. Calyx of 

 Eumex uncatus, composed of two verticils or whorls ; the outer, ce, having short and 

 entii'e divisions ; the inner, ci, having larger divisions, vphich exhibit at the margin narrow 

 hooked projections, and have on the back a tubercular swelling, g. 



