The Genus Lachenalia

Just out: The Genus Lachenalia by Graham Duncan , the latest in the series of Botanical Magazine Monographs from Kew Publishing.

Lachenalia is a genus of about 130 species of bulbous plant from southern Africa, fitting well into the coherent family Hyacinthaceae, though this is now subsumed into a broadly defined Asparagaceae. The majority of species are quite short in stature - few exceed 15 cm - and some have distinctly small and dingily-coloured flowers. On the other hand, many have large, conspicuous and ornamental flowers in an array of  colours ranging from sea-green or blue to rich red and clear bright pink, often complemented by attractively marked leaves. A handful of species occur in Namibia, but the majority are South African endemics, often very locally so, with, (as usual), the greatest diversity in the Western Cape. This diversity of species and their presence in distinct habitats makes Lachenalia a fascinating genus to get know. I have had little success growing them in a crowded greenhouse, but on both occasions I've been at the Cape in springtime (i.e. late August-September) they have been a subject of fascination out in the veld and I've always wanted to know more about them.

Since 1988 the standard work on the genus has been Graham Duncan's The Lachenalia Handbook, a slim book published by Kirstenbosch. Although botanically useful, it is essentially a gardener's guide. Or was: it is now comprehensively rendered obsolete by Graham's magnificent new book The Genus Lachenalia, published last month by Kew Publishing. His interest in the genus goes back a long way: the first of his referenced publications on the subject dates to 1978, when he was 19 and has continued in a great sweep until the present culmination of his experience in this book. Although he is interested in all (and grows most) South African bulbs, there is no doubt that his true passion is for Lachenalia.

Graham Duncan in the bulb house at Kirstenbosch, with Lachenalia duncanii, named in his honour by his mentor, Miss Winsome Barker, in 1989.

 

L. duncanii: the smaller-flowered species
 repay close inspection.



The book is a substantial tome of 479 pages, handsomely bound in red boards with a red ribbon bookmark - important production qualities when the RRP is £120. Despite this steep price I suspect it will sell out fast, as the print-run is less than a thousand copies and this is going to be an essential reference work for anyone interested in South African bulbs. Each of the 133 species is given a full description, with notes on its botanical history, distinguishing characters and affinities, ecology and distribution, etc. Lengthy introductory chapters cover the same subjects as an an overview of the genus, and include a substantial chapter on cultivation and propagation. The text is very well written, with all points clearly made - and miraculously free of typos (I have found only one, on p78).

L. flava, by W. Barker     

Despite having been studied for centuries, and being popular with students of the Cape flora, eleven new species are described in this account, including one, Lachenalia thunbergii, that was first collected by C.P. Thunberg (as in the genus Thunbergia), who first collected it in 1774 in what is still the only known location for the species, the top of the Riebeek Kasteel mountain. It and several other showy-flowered species had been included into a widely circumscribed L. aloides until recently: others liberated from this embrace are L. quadricolor, L. vanzyliae, L. flava and another new species, L. callista. All are distinct in morphology, ecology and distribution. I suspect that for many growers, at least, the inclusion  of the former genus Polyxena in Lachenalia (as a subgenus) will be difficult to accept, but all studies indicate that this is where this distinct group, with its upwards-facing, usually actinomorphic flowers belongs. Traditionalists will be glad to know that this revision of the genus is based almost entirely on morphology, though chromosome counts are employed too. So far DNA analysis has proven difficult in Lachenalia.

 

The Genus Lachenalia is copiously illustrated with photographs, scanning electron micrographs, line-drawings and a large number of plates of botanically accurate watercolours by several artists. Quite a few are by the former Kirstenbosch botanist, Miss Winsome Barker (1907-1994), whose passion for Lachenalia was passed on to Graham. Her career with the genus spanned 59 years, and it is a fascinating, though sad, fact, that she was able to inspect a significant collection of early type specimens in Vienna before they were destroyed in World War Two. Graham would be the first to admit that he has built on her foundations, and it is lovely to see her paintings being used among those by recognised greats in south African botanical art, notably Fay Anderson, Elbe Joubert and (to my mind), the incomparable Elaphie Ward-Hillhorst. The photographs, mostly by Graham Duncan, usually show plants in the wild, but are sometimes of specimens he's cultivated at Kirstenbosch.

L. verticillata, by Fay Anderson.
A lot of lachenalias have beautifully marked foliage.

Lachenalia orchioides var. orchioides near Somerset West, 2010.This widespread species was one of the first to be known to Europeans, being first illustrated in 1700.

Lachenalias in cultivation in the bulb house in the Kirstenbosch nursery: this is where Graham Duncan has practised his skills for over 30 years, gaining unequalled knowledge of the genus in cultivation.

It seems very improbable that this will be Graham Duncan's last word on Lachenalia. As he says, molecular analysis has proven difficult so far, but without it it is difficult to work out true relationships between the species. When the necessary techniques are resolved we can expect fresh revelations and more publications on this remarkable genus - but for now this lovely book will serve us well. It is available from www.kewbooks.com or other sources (ISBN 978 1 84246 382 6).