About 100 species of mainly perennials from the high Andes of Chile and Argentina north to Peru, Bolivia and Ecuador, possibly also in Colombia. All but a handful are perennial, forming either few rosetted tufts or, commonly, condensed cushions, the leaves often intricately lobed and wreathed in silky hairs. Flowers stemless or subsessile, five-petalled and variously cup-shaped, sometimes with a long floral tube, the stamens united in a column, corolla any colour from white through every shade of pink to scarlet, pale lilac to rich blue, (sometimes bicoloured or striped) and in a few species alternately copper, yellow and green. The genus is defined by the manner in which the peduncle and stipules arise direct from the petiole bases, and the absence of involucral bracts; the various species are often separated by quite subtle differences in leaf shape, or seed capsule morphology.

Uses

Until recently the genus tended to be written off as impossible - though considering how few gardeners had ever made an attempt, this was at best hasty. It is now realised that, whilst challenging, some at least will grow and flower under lowland condi tions, enduring in the open garden if provided with a draughty position on a raised bed and glass cover over the winter months. Cuttings root readily (in one case they were simply poked in the alpine house plunge) and the kidney-shaped seeds have not proved difficult to germinate on those very few occasions when they have been made available. Seed has apparently not been set in cultivation, and as an aside it is worth noting that some species have been found to be effectively dioecious. Of the difficulties so far encountered, etiolation when given glass protection, collapse following hot 'muggy' weather (it is seldom anything approaching warm at 5000m and upwards, where some of these plants grow), unseasonal growth leading to botrytis infection over the wintertime, susceptibility to Hollyhock Rust, and collapse following undue root disturbance, are the most significant. In many cases a thick and woody taproot is formed, and whilst this is resilient to attack at its apex, new shoots arising from dormant growth buds in the event of decapitation, tolerance of underground unanchoring is limited. In their first year the seedling may seem rather spindly, but in the second season a mass of new shoots may fill in further down the expanding caudex, though these too will readily etiolate. The majority of the species grow in loose volcanic detritus and bleak screes, but some at least choose different habitats, including sparse turf, cushion plant communities, moist rocky stream banks and even (rarely) peaty soils. Add to this the information that whilst a number inhabit high altitude salt flats and the montane wastes of the Atacama, others are used to year round rainfall, often blooming at a time when storms lash the mountainsides, or indeed sending up a succession of flowers virtually the year round, and it becomes clear that some species are likely to prove more reliable in our gardens than others. Many species do not experience a reliable snow cover, and they remain continuously in growth. A more certain trigger for growth is precipitation, for species from the drier regions may in effect shut down if moisture levels are low, the outer leaves withering away to leave the rosette core enduring, kept alive by the reserve stored in a taproot system often measured by the metre, which can in some cases tide plants over a dry season when rainfall is either sparse of non-existent. Note too the often hairy foliage, sodden after a heavy mist: this works to the plant's advantage in the wild, but causes all sorts of difficulties in our sometimes dank climate. Alpine house protection may be valid during the early stages of cultivation, perhaps sowing the seeds individually in 7.5cm pots filled with a neutral, scree and aggregate type compost, but it is worth attempting a plant or two outdoors, where the greater root run and improved insulation may well be appreciated. Slugs seem especially drawn to the shoots, and plants have lapsed from cultivation on this account.