146 The Flora of Wiltshire. 
character for it to be considered truly indigenous to the county. 
Further observations on its distribution in Wiltshire are still 
desirable, H. viridis having been not unfrequently recorded for H. 
fetidus, hence arises much confusion with regard to their respective 
stations. Haller reckons up all the reputed virtues of Hellebore 
under this species, which, indeed, seems to be what German prac- 
titioners have substituted for the true plant of the Ancients, H. 
officinalis, (Sibth) in Fl. Grace. t. 523. 
To the botanical student the Hellebore affords an excellent illus- 
tration of some of the more important doctrines of modern botanical 
science. The flowers of most plants possess two series of envelopes, 
which surround and enclose the fertilizing organs. The outer 
envelope being generally green and somewhat of a leafy appearance, 
is called the calyx, whilst the inner one is variously and beautifully 
coloured, and receives the name of corol/a. Example, Rose, Prim- 
rose, &c. Some plants, however, as the Tulip, Mezereon, Hellebore, 
&c., are furnished but with one envelope, which is variously uhder- 
stood and differently named by Linnean and Jussieuean botanists. 
The former considering the nature of the plant in question to be 
determined principally by its colour, describe the Tulip and Mezereon 
to have a corolla only, whilst the latter regarding the colour and 
appearance of the plant as unimportant, consider it wholly in re- 
ference to its situation and structure. Hence these botanists describe 
the single floral envelope of the Tulip and Mezereon, &c. as a calyx, 
the corolla being entirely absent. Some botanists, as Hooker, Mirbel, 
and Brown, unwilling to enlist themselves on either side, have 
adopted the convenient term Perianth, (peri about, and anthos the 
flower,) to describe the single envelope of the Tulip, Mezereon, &c., 
and describe its parts as petaléid or calycdid, according as they are 
coloured and resemble a blossom, or are green and leafy like a calyz. 
De Candolle has proposed the term Perigonium, (peri, and gone, a 
Greek word used in botanical writings, to signify the stamens and 
pistils,) for the single envelope, whatever may be its appearance, and 
calls the separate parts of which it consists Tepa/s, in contradistinc- 
tion to the petals of the corolla, and the sepals of the calyx. I shall 
now endeavour to point out the principles by which the botanical 
