ACCOUNT OF GENUS SEDUM AS FOUND IN CULTIVATION. 7 



white flowers ; stoloniferum is less frequently seen in gardens, and 

 Stevenianum and proponticum almost unknown. The remaining 

 members of the group, ohtusifoUum, Millii, and involucratum, from 

 the Caucasus, and Baileyi from China, are not, I believe, in cultivation. 

 The Sempervivoides group includes two remarkable biennial plants, 

 S. sempervivoides and S. pilosum, which form dense plump leaf-rosettes 

 like those of the genus Sempervivum, and in their second year produce 

 masses of showy red flowers. Both species are now well known in 

 good collections. For the rest, the Sedums of the Caucasus region, 

 which number some twenty in all, include a few famiUar European 

 species — maximum, album, acre, sexangulare — a few small perennials 

 not found elsewhere — gracile, tenellum, and suhulatum, the first of 

 which is in cultivation — and some Uttle annual species. 



Literature.— LiPSKY, "Flora Caucasica," 1899 (in Russian). 

 Hamet, "Revision des Sedums du Caucase." Trd. Bot. Sada, Tifiis, 

 8, Part III., 1908. 



Note. — Syria, Mesopotamia, and Persia yield a number of Sedums, 

 mostly small annuals. 



Siberia and Central Asia. 



Just as the Caucasus region is the headquarters of the small and 

 distinct group of Sedums of which the familiar spurium is typical, so 

 we find focussed in Eastern Siberia and the northern parts of China 

 and Japan a compact httle group of thick-rooted, flat-leaved, yellow- 

 flowered species — the Aizoon group. These include five — Aizoon, 

 Selskyanum, hybridum, kamtschaticum, and Middendorffianum — of 

 which the first and third were known to Linnaeus, and all have been 

 long in cultivation ; and the two more, Ellacombianum and floriferum, 

 lately described by myself from hving material. Only two of the 

 group are not in cultivation — S. Sikokianum and S. Yabeanum, both 

 of Japan. For the rest, the Siberian and Central Asiatic Sedum flora 

 is made up mainly of plants of the Rhodiola and Telephium sections, 

 many of which occur, some of them extending far to the northward. 

 But the main centre of the Rhodiola section Hes farther south, in the 

 Himalayan region, and that of the Telephiums south-eastward, in 

 China and Japan. 



Literature. — Maximowicz, "Diagnoses Plantarum Novarum 

 Asiaticarum." Bull. Acad. Imper. des Sciences de Si. Petersbourg, 

 29, 1883. (Reprinted in Melanges Biologiques, 11.) 



The Himalayan Region. 



The Himalayas are par excellence the headquarters of the Rhodiola 

 section of Sedum ; not that many species of that group are not found 

 in neighbouring regions — e.g. Yunnan — but in the Himalayas the 

 Rhodiolas are so abundant as to form a feature of the vegetation of 

 the higher grounds, and only few other Sedums occur, while in Yunnan 

 many other species are found. A good many of the earlier discovered 



