Crocosmia and Chasmanthe [Hardcover]

An authoritative reference on two groups of plants deservedly popular as border subjects in warm-climate gardens.Rock Garden Quarterly, Spring 2005 (Rock Garden Quarterly )

This work is recommended for large gardening collections. January Adams, American Reference Books Annual, 2005 (American Reference Books Annual )

This is a must book for everyone interested in these fine garden plants.Rod Saunders, Bulb Chat, December 2004 (Bulb Chat )

Here at last, these beautiful bulbs are fully described and illustrated. Spring-flowering Chasmanthe is a plant for areas of mild winter, but Crocosmia can endure winter temperatures. They flower from early summer well into fall and provide wonderful displays of warm red and orange when the garden often has little else to offer except annuals. A descriptive list of more than 400 Crocosmia cultivars concludes the complete horticultural account of the genera. Superb watercolors of the species and many of the more important cultivars are complemented by charming pencil sketches of each species in its native habitat.

John Manning was born in Pietermaritzburg, South Africa, and has been a research scientist in the Compton Herbarium at the National Botanical Institute, South Africa, since 1989. He works at Kirstenbosch National Botanical Garden in Cape Town, one of the world's great botanical gardens and an important center for research on the African flora. Although he has studied the anatomy, embryology and seed development of plants in diverse families, including the Fabaceae, Proteaceae and Stilbaceae, he has focused his research more recently on the Iridaceae, collaborating on various research projects with Peter Goldblatt. Together they have investigated the evolution and pollination biology of the African genus Lapeirousia and the systematics, pollination systems and evolution of Gladiolus in southern Africa. John and Peter have coauthored several books, including Gladiolus in Southern Africa and various wildflower guides to the southern African flora, the most recent of which was Wildflowers of the Fairest Cape (Redroof Design and Timber Press, 2000). John is also an accomplished botanical artist and photographer; his drawings have been published in numerous books and scientific journals.

Peter Goldblatt is the B.A. Krukoff Curator of African Botany at the Missouri Botanical Garden in St. Louis. Throughout his botanical career he has concentrated his attention on the Iridaceae and has shown particular interest in its African members.

The pollination of Chasmanthe and Crocosmia has not been much studied, and most of the observations here are original. The flowers of all three species of Chasmanthe have the characteristics of other African Iridaceae, and of plants in general, that are pollinated by sunbirds, species of Nectarinia (Goldblatt et al. 1999). They are orange to red, sometimes with green or yellow markings, and have an elongate tube, relatively wide and more or less tubular in the upper half and slender in the basal half. These flowers produce comparatively large quantities of nectar from septal nectaries, that is, nectar-secreting glands in the radial walls (septa) of the ovary. Nectar is secreted via small pores in the top of the ovary directly into the perianth tube, where it accumulates when the flowers are open. Nectar volumes of as much as 30 l (microliters) have been recorded in Chasmanthe aethiopica. In general, nectars that flowers offer to birds have a relatively low nectar concentration, though there are some important exceptions, even within the family Iridaceae. Chasmanthe species, however, do conform to this trend. Nectar concentrations of 10% sugar have been reported for C. bicolor, and 15.717% sugar for C. aethiopica and C. floribunda, levels that are consistent with bird pollination. Nectar sugar chemistry also reflects the bird pollination in these species, for the nectar of Chasmanthe flowers has high proportions of the so-called pentose sugars (glucose and fructose) and low levels of the hexose sugar (sucrose). Species of subfamily Crocoideae that are pollinated by bees, moths and long-proboscid flies invariably have nectars with higher sucrose concentrations: so-called hexose-rich or sucrose-dominant nectars in the terminology of Baker and Baker (1983). Comparable nectar characteristics have been obtained for two bird pollinated Crocosmia species for which we have nectar data, C. fucata and C. paniculata. Flowers of C. fucata produce as much as 11.5 l of nectar with an average concentration of 18.0% sugar, figures closely matched by those of C. paniculata, which has a nectar concentration of 17.4%. Analysis of C. fucata nectar also shows unusually high levels of glucose and fructose (pentose sugars) and a sucrose: pentose ratio of 0.53, which is regarded as pentose rich (Baker and Baker 1983), a pattern consistent with bird pollination. The only other species of Crocosmia for which we have nectar data are C. aurea and C. pottsii. The nodding flowers or C. aurea, evidently adapted for pollination by large Papilio butterflies, produce as much as 3.7 l of nectar with average sugar concentrations for different population samples of 17.724.3%. The flowers of C. pottsii, which appear to be adapted for pollination by bees, have an average sugar concentration of 23.2%. No data are available for nectar sugar chemistry. The relatively low sugar concentration in C. aurea nectar is typical of butterfly-pollinated flowers. Chasmanthe species have long b