The southern African Plectranthus and the Art of Turning Shade to Glade, by Ernst van Jaarsveld

The southern African Plectranthus and the Art of Turning Shade to Glade, by Ernst van Jaarsveld. Fernwood Press. Cape Town, South Africa 2006. ISBN 9781874950806 / ISBN 978-1-874950-80-6

Images from The southern African Plectranthus, by Ernst van Jaarsveld. Fernwood Press. Cape Town, South Africa 2006. ISBN 1874950806 / ISBN 1-874950-80-6

Although it has been realized for a number of years that many of our Plectranthus species would make attractive garden subjects, it is only recently, since Ernst van Jaarsveld, author of The southern African Plectranthus and the Art of Turning Shade to Glade, took an interest in them, that gardeners in general are becoming aware of them.

Ernst van Jaarsveld  

Displays held at Kirstenbosch during the past few years, organized initially by Ernst van Jaarsveld and later by other members of the Kirstenbosch staff, have demonstrated many species growing to perfection, either in massed shrub plantings or as groundcovers in shady places. In addition, several species were shown to be well suited for growing as ornamental pot plants in hanging baskets. Since his appointment to the staff of the National Botanical Gardens of South Africa, stationed first at Nelspruit from 1974 to 1976 and then at Kirstenbosch, Ernst van Jaarsveld has made a significant contribution to our knowledge of the genus by collecting specimens throughout South Africa. It is obvious that he has an eagle eye for spotting unusual plants and in the process has discovered three new species, one of which I had the pleasure of naming in his honour. His collections have also added greatly to our awareness of the extent to which species can vary, whilst several appear to be interspecific hybrids.The fact that he has regularly collected living material as well has greatly added to the value of his contributions. My own interest in the group goes back over thirty years when I found that it was almost impossible to make a reliable identification of a Plectranthus specimen in the herbarium. This was partly because the plants are difficult to turn into good herbarium specimens, with the result that the early attempts at classification often increased the confusion. Fortunately the original collecting sites of most species are on record, and the ease with which plants can be propagated by cuttings greatly facilitated their study in cultivation. In addition to its horticultural interest, Plectranthus shows a number of fascinating features which are worthy of closer study. The vegetative parts are often characteristically scented, from the rich, pleasant fragrance of P. amboinicus and the citronella-like scent of P. laxijlorus to the strong and rather repellent odour of P. neochilus. As constituted at present, the genus forms a somewhat heterogeneous group of about 300 species whose distribution extends from Africa and Madagascar, where the main concentrations are, to the southern Arabian peninsula and India, with a few outliers in Malesia and Australia. Preliminary cytological studies have revealed that several series exist within the genus, each differing in basic chromosome numbers, and it is possible that the whole group will eventually be subdivided into several genera. However, such a step would be unwise until the numerous tropical African species have been thoroughly sorted out and their affinities with the southern African species established. (L. E. Codd, Botanical Research Institute, Pretoria)

The Plectranthus species in Southern Africa:

Plectranthus aliciae, Plectranthus ambiguus, Plectranthus amboinicus, Plectranthus barbatus, Plectranthus candelabriformis, Plectranthus caninus, Plectranthus ciliatus, Plectranthus crassus, Plectranthus cylindraceus, Plectranthus dinteri, Plectranthus dolichopodus, Plectranthus dolomiticus, Plectranthus ecklonii, Plectranthus elegantulus, Plectranthus ernstii, Plectranthus esculentus, Plectranthus fruticosus, Plectranthus grallatus, Plectranthus grandidentatus, Plectranthus hadiensis, Plectranthus hereroensis, Plectranthus hilliardiae, Plectranthus laxiflorus, Plectranthus lucidus, Plectranthus madagascariensis, Plectranthus malvinus, Plectranthus mirabilis, Plectranthus mutabilis, Plectranthus mzimvubuensis, Plectranthus neochilus, Plectranthus oertendahlii, Plectranthus oribiensis, Plectranthus ornatus, Plectranthus pentheri, Plectranthus petiolaris, Plectranthus porcatus, Plectranthus praetermissus, Plectranthus psammophilus, Plectranthus purpuratus, Plectranthus ramosior, Plectranthus reflexus, Plectranthus rehmannii, Plectranthus rubropunctatus, Plectranthus saccatus, Plectranthus sanguineus, Plectranthus spicatus, Plectranthus strigosus, Plectranthus stylesii, Plectranthus swynnertonii, Plectranthus tetensis, Plectranthus tetragonus, Plectranthus unguentarius, Plectranthus venteri, Plectranthus verticillatus, Plectranthus woodii, Plectranthus xerophilus, Plectranthus zuluensis.

This is an excerpt from: The southern African Plectranthus and the Art of Turning Shade to Glade, by Ernst van Jaarsveld.

Title: The southern African Plectranthus and the Art of Turning Shade to Glade, by Ernst van Jaarsveld
Author: Ernst van Jaarsveld
Illustrator: Vicki Thomas
Publisher: Fernwood Press
Cape Town, South Africa 2006
ISBN 1874950806 / ISBN 1-874950-80-6
ISBN 9781874950806 / ISBN 978-1-874950-80-6
Hardcover, dustjacket, 24 x 31 cm, 176 pages, throughout colour photos and illustrations