Authors

John C. Manning

John C. Manning is Senior Specialist Scientist in the Compton Herbarium, South African National Biodiversity Institute, Kirstenbosch. 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 whose drawings have been published in numerous books and scientific journals.

Timber Press: Which Cape bulb were you most excited about describing?

John Manning: Each one is exciting in its own way but one of the most dramatic discoveries must be Moraea hesperantha. We found it quite by chance in an area with which we are very familiar and which has been visited by many botanists over the past centuries. We had spent some time looking at local flowers at a particular locality around midday but decided to return late in the afternoon when the light would be better for photography. Arriving back some hours later we were just in time to witness these large, white, iris-like flowers opening before our amazed eyes: they had been quite invisible to us earlier in the day and were only now opening up in time for the evening. Naturally, we had to commemorate this wonderful experience in the name of the plant.

Timber: What would you expect gardeners to find most appealing about this book? How does that contrast with what a botanist might find intriguing about the book?

John: For gardeners it must be the range of illustrations of wild plants, many of which will be unfamiliar to the majority, bearing the most up-to-date names, combined with the information on where the plants grow in nature. The cultivation notes are aimed at both Northern and Southern Hemisphere gardeners and include recommendation for both pot and garden cultivation. For the botanist, the value of the Encyclopedia lies in its completeness and the high standard of the information. It is the only complete, modern account of Cape bulbs, with the advantage that it is written by experts who know the plants in the field, plus it is beautifully illustrated.

Peter Goldblatt: Both botanists and gardeners will find the book to be a complete account of the bulbous plants of the Cape that is botanically accurate as to description and current plant name. The numerous illustrations, many not available anywhere else, provide a records of the plants that no verbal account can possibly achieve. Misidentifications of plants in horticulture abound. We hope this book will help keep these to a minimum. As an example, I recently saw Cape Tritonia corms for sale in Portland under the name "assorted Ixias". The illustration of said plants was of a selection of Tritonias. Reference to our book should immediately eliminate this kind of confusion.

Timber You mention in the book that "agriculture, mining, and urban sprawl are exerting increasing pressure on the survival of many species in the wild." To what extent have these forces affected Cape ecosystems? Would you recommend any particular strategies for maintaining and conserving the astonishing biodiversity of the region?

John: These forces have significantly reduced the areas of natural vegetation, especially in the lowlands. Although only one or two Cape bulbs are definitely extinct in the wild, many are on the brink of extinction. The preservation of small areas of natural habitat will ensure their survival in the short term but such patches are doomed to become eventually overrun by introduced annual grasses and other weeds of disturbed or cultivated lands. The only long-term solution is to set aside large areas of relatively unspoiled land. For many Cape bulbs, however, this will be too late.

Peter: The result of human activity in many places is the transformation of the landscape and near total elimination locally of native plants; sometimes these may included rare and endangered plants. We need more reserves, and larger ones that are managed properly to maintain plant diversity. We would ideally like to see more people engaged in conservation activities and the enforcement of laws for plant protection. Right now it is totally legal for a landowner to plough up a field that contains the last known plants of a species. Plant hunters are rarely prosecuted for pillaging native plants for gardens or collections or for sale. Threats to the flora are numerous and often unnecessary. Road verges are often sprayed with weed killer unnecessarily, resulting in loss of all but the true weeds of cultivation. Some reserves are polluted by runoff of fertilizer and spreading weeds form adjacent fields. Others are overstocked with game, sometimes not even native to that particular habitat. The human population, the ultimate threat, continues to grow at an alarming rate, and with increasing prosperity demands better, larger housing, better food, more possessions, and room for leisure activity. All these factors create pressure on land to be used for human needs. What can be done? I wonder, in the long term, if we can do anything lasting to save many of the Cape's and the world's plant species.

Timber: To what would you attribute the high level of endemism of the Cape Floral Region, that there are so many species found there and nowhere else?

John: The cause is essentially the diversity of natural habitats over such a short distance. This is largely a result of the steep environmental gradients, particularly the combination of steep mountains made from one soil type (acidic sandstone) separated from one another by valleys of a different soil (shales and clays). These different soils rarely support the same bulbs, which means that each mountain range or valley is effectively isolated from the next, allowing its bulb flora to evolve independently. Furthermore, the mountain ranges run largely parallel to the coasts, with the result that they have very definite wet and dry sides, again providing more habitats for different bulbs. Finally, the sheer range of different microclimates in the Cape is very great, from hot inland valleys like the Breede and Tanqua to the cold Roggeveld Plateau and Hantam Mountains.

Peter: The answer to this question is complex and a little uncertain. The soils are a mosaic of clays and sands and granites that allow different niches for plants. The landscape is also highly dissected, the topographic diversity ranges from sea level to 5-7000 feet in a relatively short distance, creating steep environmental gradients, again providing multiple niches for plants. The soils are mostly poor and acidic, and that favors production of fruits and seeds that provide little or no nutrients for potential dispersal agents. This in effect means plants at the Cape generally have low dispersal capabilities. That favors local genetic isolation, leading to population divergence and ultimately speciation. In addition, the relative climatic stability (no glaciation, no desertification) for a longer period than elsewhere in comparable latitudes means less extinction, hence more species in the flora.

Timber: Why are bulbs and other geophytes so much more abundant in the Cape region than in other Mediterranean climates?

John: The reasons are probably complex and involve not only a relatively open scrub vegetation in which bulbs can thrive without being shaded out but also the predictability of the very seasonal climate. There are never severe droughts that extend over several seasons, meaning that the bulbs are certain to be able to thrive each year. In areas of unpredictable climate the plants that are favored are often annuals, which can respond rapidly and opportunistically to the rainfall. Bulbs require a more stable but still seasonal climate to thrive.

Peter: I think that may be an historical accident. Or there might have been a longer time for the climate to develop, and the climate may have been relatively stable for longer than elsewhere.

Timber: There are undoubtedly Cape bulbs that have yet to be described. You in fact mention that there are several kinds of plants that are temporarily designated with numbers. Do you have an idea of how many species might still be awaiting discovery?

John: We have described between five and ten new bulbs each year for the last few years and I expect this to continue, although not at this rate. Possibly two to five each year for the next few years is a reasonable guess.

Peter: I suppose maybe 30 to 50 more species await discovery.

Timber: Why did you choose Timber Press as your publisher instead of going with a South African one?

John: Timber have proven themselves as a first-rate publisher of botanical books with an editorial staff that is qualified in the scientific aspects of botany. Couple this with an awesome international distribution network and you have a recipe for success.

Peter: I have worked with TP before and it has always been a good experience. Also, no South African publisher we tried would take the book.