oe and richly coloured, having much of the appearance of t 
56° THE FLORAL ENVELOPE. 
VI, THE FLORAL ENVELOPE. 
336. This consists of one or two whorls of leaves of a pe- 
culiar form and appearance, immediately surrounding the 
sexual organs (287.) When there are two whorls, the inner, 
that nearest to the stamens and pistil, is called corolla, the 
outer is called calyx, and the plant is called dichlamydeous. 
When, there is only one whorl, it receives the name of e 
whatever be its form or appearance ; and the plant is called 
monochlamydeous. 
337. Considered as a whole, the floral envelope, whetl 
there be one whorl or two present, receives the name of pé- 
rianth (perianthium or perigonium.) The perianth is called 
simple, when it consists of the calyx alone ; double, when both 
calyx and corolla are present. ee 
_ 338. When neither calyx nor corolla is present, the plant 
is called achlamydeous, and the sexual organs are said to be 
naked, as in Wake Robin (Arum), or in Mare’s Tail. 
Fig. 13, par. 287. 
pare VIl. THE CALYX. 
mediately below it. It is called flower-cup, from em 
the lower part of the corolla, which appears to rest 
See b, Fig. 12, par. 286, 
340. When the corolla is present, the calyx is generé 
shorter than it after the flower has expanded, but longer 4 
embracing it before. It is usually of a green colour. 
there is no corolla, the calyx (336) is generally thick, I 
