Covert pollination

July 31, 2022

When it comes to the business of reproduction, some plants are transparent in their mode of attracting pollinators – offering landing pads, bright colour signals and other adaptations like bilateral symmetry. Others rely on deception.

Certain members of the aroid family are well-known for practicing false advertising to attract insect pollinators – notably flies, by simulating the smell of carrion. The net effect of this frequently makes news headlines when the giant flowerheads of Amorphophallus titanum stink out glasshouses at botanical gardens throughout the world.

The flowers of certain fritillaries (such as Fritillaria biflora var. biflora, pictured below) are nowhere near being in the same league, with the scent generally only discernible on close inspection. This will be due to the fact that their lightly stinky flowers are much easier for flies to find in open meadows and chaparral than a titan arum broadcasting its presence in the understorey of tropical rainforests.

Opinion (or perhaps just olfactory function) varies regarding the strength of the smells that these beautiful flowers emanate, so I can only report from the subjective standpoint of my own nose.

Although some texts have rude things to say about F. biflora var. biflora‘s scent, I find Fritillaria davisii (a Greek species) to hold a stronger scent than both varieties of F. biflora that are currently in bloom in our garden – including the form of Fritillaria biflora var. ineziana pictured below. The latter is an interesting taxon associated with serpentine areas in California, as are a number of species from this region.

On a somewhat different note, the sweetly-scented flowers of Lachenalia pustulata are currently at their peak (as shown above, left) . This is one of a number of species of Lachenalia that we grow within our own garden and in projects, with their flowering spanning most of winter.

The last image within this journal entry is of a much more uncommon plant, which has flowered for the first time for us. Gladiolus aureus is a golden-flowered species that is critically endangered in the wild in South Africa.

That term barely describes the depth of its plight, as fewer than 10 plants remain in the wild, leaving this graceful species teetering on the edge of extinction. Although rare in cultivation, it is well established in the collections of important botanical gardens, although there is no substitute for the enduring presence of species in their wild habitats.