"Cereus-validus" wrote in message
m...
Despite the fact that the average gardener has absolutely no idea why any
plant is so named the way it is, I will tell you why.

Bottom line:

Type species for genus Sedum L. is Sedum acre L. and is a dwarf evergreen
perennial with connate kyphocarpic carpels.

Genus Hylotelephium H.Ohba (formerly Sedum section Telephium) are
deciduous
perennials, usually with a tuberous rootstock, and with separate stipitate
(slender stalked) carpels.

It should be obvious that the growth form of Hylotelephium is very
different
from that of typical Sedum.

Dissect the flowers and you will the differences between the two genera.

While this is all well and good in the interest of taxonomic accuracy, you
will not find these plants in the commercial trade listed under this name,
nor will you find Chamaecyparis nootkatensis listed as Xanocyparis, or
Platycladus listed as Biota or seldom Cimicifuga listed as Actaea or even
very often Clematis paniculata correctly labeled as C. terniflora. Old
habits die hard.