26 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY, 
The remaining Asiatic tender species are few, and various : 
Chaneti Hamet (section Seda Genuina, but anomalous). 
Someni Hamet 
Finally, of the few species of Sedum inhabiting the Atlantic Islands, 
two are in cultivation belonging to the section Seda Genuina — ■ 
5. lancerottense Murray, and S. nudum Aiton. 
The only large geographical region where Sedums occur not repre- 
sented in the species known in cultivation is Central Africa, where 
a few interesting species are found on high mountains (see p. 6). 
Section Rhodiola ScopoH, " Introd. ad Hist. Nat.," 255, 1777 
(char. ampl). Praeger in Trans. Bot. Soc. Edinh., 27, 107, 1917. 
Rhodiola Linn., " Genera Plantarum," ed. i. 318, 1777 (pro genere). 
Perennial. Caudex fleshy, crowned with leaves with a broad 
clasping base (often reduced to membranous, deltoid or semi- 
orbicular scales, or becoming so with age) from the axils of which leafy 
flowering-shoots are produced. Flowers 4- or 5-parted, dioecious or 
hermaphrodite. Hardy plants, mostly Asiatic. 
Linnaeus founded his genus to include a single species, R. rosea, 
the well-known Roseroot. Scopoli reduced Rhodiola to a section 
of Sedum, and most authors have followed him in this. While some 
have limited Rhodiola to species which, like roseum, have unisexual 
and 4-parted flowers, others have included plants like S. crassipes, 
which have hermaphrodite 5-parted flowers combined with the 
characteristic thick scaly Rhodiola rootstock. I have endeavoured * 
to show that a continuous series of forms leads from the roseum type 
with dioecious 4-parted flowers, poorly developed scales, and massive 
rootstocks, through others with hermaphrodite 5-parted flowers and 
larger scales with a leaf-like tip, to forms like 5. Praegerianum and 
S. primuloides, with hermaphrodite flowers, well-developed leaves 
instead of scales crowning the rootstock, and short or slender root- 
stocks. Some members of each group are in cultivation. 
Series L Rhodiolae sensu stricto. 
Flowers usually unisexual and 4-parted, caudex usually elongate 
or greatly thickened. Carpels usually short and crowned with short 
styles reflexed in fruit. 
viscosum Praeger/ 
formosanum N. E. Brown 
Leblancae Hamet 
Sempervivoides. 
section Epeteium. 
X. Description of Species. 
SECTION L— RHODIOLA. 
* Praeger, " On the Affinities of Sedum Praegerianum W. W. Smith, 
with a Tentative Classification of the Section Rhodiola." Trans. Bot. Soc, 
Edinb., 27, 191 7. 
