The genus Sedum (sensu lato) is a large and diverse grouping of species. Various molecular studies since 1995 have indicated that many of these species would be better placed within segregate genera - a treatment that is not universally recognized. We have chosen to follow the Flora of China[
] and Flora of N. America[
] in recognizing these new genera. When the nomenclatural, biogeographic, and morphological data has become available for many other groupings within Sedum, it is likely that more new genera will be established - to date we have transferred a number of species to the genera Hylotelephium. Phedimus and Rhodeola[
Sedum diffusum is an evergreen, perennial plant with a fleshy rootstock; the stems are creeping with spreading branches, the plant growing around 15cm tall[
The plant can be used in 'green roof' systems, which are used to insulate buildings, provide wildlife habitats amd ameliorate the climate. It is grown as an ornamental in gardens.
All species in the genus Sedum (including the closely allied genera such as Hylotelephium and Phedimus) have more or less edible leaves and young flowering stems, though they are not always totally desireable with several species having bitter, acrid or peppery flavours!
However, the plants contain various alkaloids including sedine and sedamine. These can sometimes cause gastric upsets, usually of a mild nature[
]. This is most likely to happen with species that have yellow flowers, though eating large quantities of any species could be problematic[
Southern N. America - Central and northern Mexico
|Other Uses Rating||
|Cultivation Status||Ornamental, Wild
Sedum diffusum is not a very cold-hardy plant, tolerating temperatures down to around -8°c when dormant[
Most Sedum species will grow best if given a moist, but well-drained, fairly fertile soil in a sunny position[
]. Many of the species will do well in quite dry positions, in poor soils and in light shade - see notes on the plant's habitat for ideas about this[
]. Most species are somewhat to very drought tolerant[
The plant is grown as an ornamental.
The flowers are white[
]. All members of this genus are said to have edible leaves, though those species that have yellow flowers can cause stomach upsets if they are eaten in quantity[
Species in this genus are often specially targeted by slugs[
Plants in this genus seem to be immune to the predations of rabbits[
We have no specific mention of edibility for this species but, in general, the leaves of all members of this genus are edible, though not always very desirable[
]. Some caution should be employed however, particularly if the plant has yellow flowers - see the notes above on toxicity[
We have seen no specific reports on medicinal uses for this species, but Sedum species (including Hylotelephium and Phedimus) generally contain various medicinally active compounds including alkaloids, tannins, cyanogenic compounds and, in particular, a range of flavanoids with anti-inflammatory and pain relieving properties. Many Sedum species are used medicinally to treat pain and inflammation - in addition a poultice made from the crushed, succulent leaves and young stems can be applied topically to cuts, wounds, burns and various skin disorders[
The plant forms a dense cushion of growth and can grow in poor, dry soils. It can be used in 'green roof' systems in order to insulate buildings, provide wildlife habitats and ameliorate the climate. The cultivar 'Burnati' has been mentioned[
Seed - surface sow in spring in well-drained soil in a sunny position in a greenhouse. Do not allow the soil to dry out. Prick out the seedlings into individual pots when they are large enough to handle. If sufficient growth is made, it is possible to plant them out during the summer, otherwise keep them in a cold-frame or greenhouse for their first winter and plant them out in early summer of the following year[
Division is very easy and can be carried out at almost any time in the growing season, though is probably best done in spring or early summer. Larger divisions can be planted out direct into their permanent positions. We have found it best to pot up the smaller divisions and grow them on in a lightly shaded position in a cold frame, planting them out once they are well established in the summer.