30 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
dried. It is a familiar member of the alpine flora of our own country, 
and is one of the most polymorphic of the variable group to which it 
belongs. Our native form, which is chosen for illustration (fig. 4), 
displays very little variation within the limits of our islands ; it is 
sub-var. continentalis of Maximo wicz {Bull. Acad. Petersb., 29, 129), 
and appears to be the form which prevails on the European moun- 
tains, spreading to Iceland and Canada. In Asia and America the 
plant becomes variable. Kegel and Tiling (" Flor. Ajanensis," 
p. 88) enumerate as varieties latifoUum, vulgare, oblongum, viride, 
crispum, pumilum, dentatuniy Stephani, humile, involucratum, ovatum, 
lanceolatum, tenuifoliumy Kirilowii. While allowing Stephani and 
Kirilowii the rank of species, Maximo wicz reduces the rest to three 
varietal types — vulgare, elongatum, and atropurpureum. The form 
occurring in Japan — Tachiroi of Franchet and Savatier — he admits 
as a fourth varietal type. Probably Maximowicz's arrangement 
goes as far as is advisable in the way of subdivision, considering the 
manner in which the forms run into each other. 
As regards America, six " species " are described under the genus 
Rhodiola in the " North American Flora " (vol. xxii. 1905) — rosea, 
neo-mexicana, alaskana, integrifolia, polygama, and roanensis. I 
have seen only R. rosea, but from the descriptions the others do not 
seem to differ from the type more than the numerous Asiatic forms, 
and probably ought at most to be given varietal rank. Further 
exploration of the American mountain regions will no doubt reveal 
intermediate and additional forms. 
I have got together in my garden a large series of cultivated forms, 
received under all kinds of names from many different sources. They 
show a wide range of variation : — Flowers — unisexual or bisexual, 
yellow, green, brick -red to dark purple. Leaves — linear-ob lanceolate 
to oblong or broadly obovate, entire to pectinately toothed, green to 
very glaucous (fig. 5, a). Stem — slender to very stout, 3 inches 
to a foot high. Rhizome — forming a thick horizontal mass or 
elongate, very thick and knotted to slender, cyhndrical, and smooth. 
I have found much difficulty in allocating these and other forms, 
which I have been able to study, to Maximowicz's four group-varieties. 
In the fpllowing notes are given first the leading characters of these 
group-varieties according to Maximowicz's description, and then 
comments on the cultivated plants which I have studied, which 
appear to belong to them. 
a. vulgare Maximowicz, Bull. Acad. Peter shourg, 29, 128. 
Illustrations. — See p. 28. 
Height, 7-12 inches. Very glaucous. Leaves imbricate, more or less elliptic, 
acute. Inflorescence dense, generally leafless. Flowers yellow, longer than the 
pedicels, stamens exserted, scales twice as long as broad. 
Here belongs the native British and Continental Roseroot, which 
is also the common garden form. European herbarium specimens 
show but little variation. The extreme glaucescence is characteristic. 
