172 



FLORAL ENVELOPES. CALYX. 



unrolled, delicate woody fibres, and other vessels, the whole being 

 enclosed in an epidermal covering, having stomata, and often hairs on 

 its outer surface, which corresponds to the under side of the leaf. 



359. _The venation of the calyx in the great divisions of the vege- 

 table kingdom, is similar to that of their leaves; parallel in Endogens, 

 reticulated in Exogens. The leaves of the calyx are usually entire 

 (fig. 269), but occasionally they are cut in various ways, as in the 

 Rose (fig. 270 c/), and they are sometimes hooked at their margins, as 

 in Rumex uncatus (fig. 271 c i). In the last-named plant, there are IWD 



whorls of calycine leaves, the outer of which, c e, are entire, and there 

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

 of the inner hooked sepals. The outer leaves, c e, may be looked upon 

 in such cases as bracts occupying an intermediate place between leaves 

 and sepals. It is rare to find the leaves of the calyx stalked. They 

 usually consist of sessile leaves, in which the laminar portion is only 

 slightly developed, and frequently the vaginal part is alone present. 

 Sepals are generally of a more or less oval, elliptical, or oblong form, 

 with the extremity either blunt or acute. In their direction they 

 are erect or reflexed (with their apices downwards), spreading out- 

 wards (divergent or patulous), or arched inwards (connivent). They 

 are usually of a greenish colour, and are called foliaceous or herbaceous ; 

 but sometimes they are coloured, as in the Fuchsia, Tropoeolum, and 

 Pomegranate, and they are then called petaloid. Whatever be its 

 colour, the external envelope of the flower must be considered as the 

 calyx. 



Fig. 269.--Pentaphyllous or pentasepalous calyx of Stellaria Holostea; sepals entire. 



Fig. 270.- -Flower of the Rose, cut vertically, c t, Tube of the calyx, c/, 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 ending in a stigma, *. 



Fig. 271. Calyx of Rumex uncatus, composed of two verticils or whorls; the outer, c e, having 

 short and entire divisions; the inner, c t, having larger divisions, which exhibit at the margin 

 narrow hooked projections, and have at their base a granular swelling, g. 



