This introduction for the topic of the week from Robin Attrill got filtered out by the our server and I have no clue why so I am forwarding it on. Mary Sue Dear all, Amongst many gardeners Oxalis tends to be rather stigmatised by the occurrence of a few weedy taxa amongst the many hundreds of species which constitute the genus. Fortunately there are also a very large number of desirable species which merit a place in cultivation. The majority of these are geophytes, predominately native to Africa and the Americas, and it is these plants that I will introduce in this weeks TOW. The most extensive number of species, and diversity of form, occurs in South Africa, principally in the winter rainfall regions. These plants, which flower from August through to April in the northern hemisphere, occur in an extraordinary range of habit, leaf shape, and flower colour, examples of which are illustrated on the PBS Wiki at http://pacificbulbsociety.org/pbswiki/index.php/…. We are indebted to the late Michael Vassar, whose enthusiasm for these plants, and generosity in distributing them, has done much to popularise oxalis as a whole. A selection of desirable, and easily grown, species includes O. orbicularis (early flowering lilac blooms over very attractive foliage with purple mid ribs and fringes to the leaflets), the O. flava complex (very variable leaf shape and flower colour, typically yellow but also white and lilac), O. hirta ( variable flower colour from almost crimson, in the form 'Gothenberg', to almost white), O. versicolor (white flowers with crimson on the reverse giving a candy stripe effect when in bud), O. massoniana (orange with a yellow centre), and, towards the end of the season, O. obtusa which possesses probably the most variable flower colour of all with the range encompassing pinks, oranges, yellows and white. I find the best means of cultivation is in pots, kept dry in summer then thoroughly watered in autumn after which they are watered on a needs basis throughout the growth period during which they are kept frost free (minimum 5 celsius). The potting medium should be well drained, and not too rich otherwise foliage will predominate at the expense of flower. These plants require excellent light to prevent etiolation. If plants are grown in open ground those species which produce bulblets at ground level (which disperse readily) should be sited with caution. A second group consists of the 'alpines' from southern South America. Three species are widely available and generally not difficult to grow - O. adenophylla, O. enneaphylla and O laciniata - all of which are very worthwhile either in pots or in a rock garden. These come into growth in late winter and flower in spring and early summer. A considerable number of species occur further north in the Americas but rather few of them are in cultivation. Identification of Oxalis tends to be a rather difficult process due to the paucity of recent literature. As mentioned by Dave Victor in a posting a few weeks ago, there is a Checklist, produced by Richard Clifton of the Geraniaceae group (ISBN: 1-899742-43-3), which assists in sourcing the literature associated with the named species but it does not contain keys. The only handbook on the Southern African species, by Salter, is almost sixty years old - a reprint was produced by Rainbow Gardens Bookshop a few years ago but I do not believe it is still in print. Copies of the original are virtually unobtainable as the print run was very small. Despite these difficulties many of the un-named plants in cultivation do have associated collection/accession numbers - particularly those originating from the Vassar collection - which can be used to provide information on their origin. Sources of Oxalis material are widespread but rather few in number. In the USA they include Telos Rare Bulbs(http://www.telosrarebulbs.com/index.html) which offers a good selection, and the PBS exchange lists contain some excellent plants from time to time. In the UK Monocot Nursery lists a small but interesting selection. Remarkably -and unfortunately! - the number of suppliers in South Africa is extemely limited but Cape Seed and Bulb (http://www.clivia.co.za/) offers a small selection. In contrast to bulbs, seed is rarely available - a combination of generally limited viability and exploding seed capsules makes it a rather difficult proposition - but the Flores and Watson seed lists sometimes contain interesting South American species. In summary I believe Oxalis to be a genus with great potential. The plants require little space and are generally easy to grow. They provide a beautiful flowers throughout the year in a range of colours that is difficult to match amongst the monocot geophytes. Why not try them????! Regards Robin Attrill