Tuesday, June 29, 2010
Sunday, June 20, 2010
It has always seemed to me that flower buds are some of the most remarkable natural objects- the botanical equivalent of a firework - containing the prepackaged, intricate beauty of a floral display just waiting to explode.............. and when it's a Clivia bud, the display can be truely impressive...
Clivia miniata hails from Kwazulu-Natal in South Africa, where it grows in dappled shade in woodlands - and so it's well adapted to life as a houseplant, in shady rooms. Scores of cultivars have been bred and it's not a difficult plant to raise from seed. I germinated a batch of seed that I collected when I self-pollinated the plant in the photograph above and most flowered within four years of germination, producing a remarkably variable batch of seedlings. Sadly, none was better than the parent plant and several produced very small flowers.
The name of this genus has its roots in Britain's imperial past and commemorates Lady Clive, Duchess of Northumberland and grand-daughter of the famous General Clive of India. The genus has a society dedicated to it - the Clivia Society - with an interesting web site.
Monday, June 14, 2010
To mark the beginning of the football World Cup in South Africa, here's a familiar South African succulent species - the partridge-breasted aloe, Aloe variegata, that's widely grown as a houseplant here in Britain. I assume the common name comes from the similarities in pattern between those beautifully variegated leaves and a bird's breast feathers, but the more direct connection between aloes and birds relates to their flowers. Like many red-flowered plants these aloes are often pollinated by birds - usually sugarbirds, which occupy the pollination niche that's filled by hummingbirds in the New World, but without their aerial agility. They are both after the same reward though - nectar, which is secreted inside those tubular flowers. You can find a guide to Aloe species here .
Thursday, June 3, 2010
I have to admit that I'm not a huge fan of broccoli as a vegetable to eat, but nothing comes close to Romanesco broccoli - in my estimation - as an vegetable to just look at. The geometrical precision of the curd, which is a mutant inflorescence made up of repeated spirals of flower buds, most of which never open, is almost hypnotic if you stare at it for long enough (especially if you've had a glass or two of wine beforehand). If you dissect one of these flower heads you soon discover that the pattern of spirals, so obvious in the whole structure, is repeated in the individual florets and again in the sub-florets (double-click on the picture for a larger image that makes this more apparent). This is what mathematicians call a fractal - each constituent part is a subset of the whole. This isn't the only plant to conform to fractal geometry - fern fronds follow the same mathematical logic.
The curds of cauliflowers and broccoli, which are naturally mutated inflorescences, are composed of buds that have proliferated to such an extent that they tend to rot away before they can flower. When I was a young postgraduate student I worked in a vegetable research station where new varieties of cauliflower were bred and was taught the technique of producing cauliflower flowers, so that they could be cross pollinated. The trick was to dissect a cauliflower into its individual flowers (scions) and to graft each of these onto a well developed decapitated cabbage seedling as a stock. Once stock and scion had united the relatively small number of buds in the dissected piece of curd would flower and the flowers could be cross pollinated. So next time you are tucking into cauliflower cheese, spare a though for the horticultural skills of the plant breeders who bred your cauliflower. GM technology may be clever and sophisticated, but greenfingers are still sometimes needed in crop breeding.