The spring flower show has many beauties, but one of our favourites is Geissorhiza ovata, with its pinkish-white, saucer-shaped flowers. However, the genus name leaves a lot to be desired when it comes to pronunciation. We generally pronounce it as “guys-so-rise-a”, but there is no official pronunciation of botanical names, so you are welcome to choose your own version!
The “rhiza” part of the name is straightforward – it comes from the Greek meaning root, although in Geissorhiza it is actually the corm, a swollen underground stem, that is being referred to. The “geisso” part is more unusual. It comes from the Greek “geisson”, a word associated with a projecting roof edge or cornice, and which could also refer to a roof or gutter tile. The name therefore evokes the tile-like arrangement of the overlapping layers covering the corm in some of the species – the feature that inspired John Belleden Ker to give the genus its name in 1803: https://www.biodiversitylibrary.org/item/14296#page/194/mode/1up.
Once you get beyond the unusual name, the plants themselves are stunning. The pinkish-white petals are deep pink on the reverse. They also have a long tube, which is this same deep pink colour and often shows through in the centre of the flower. The flowering stems are reddish, while the broad bracts below the flowers are a contrasting green. To add to the overall effect, there is sometimes a darker ring of pink around the mouth of the tube.
The species belongs to subgenus Weihea, a group of species within Geissorhiza with a distinctive type of corm. Its outer layers are arranged concentrically, with the older layers enclosed by the newer ones, and they split vertically as they age. This is quite different from the species in subgenus Geissorhiza, where the old layers overlap and break up into conspicuous, tile-like segments – the feature that gave the genus its name.
At the base of the plant are two or three broad, almost ovate leaves – hence the specific name “ovata”, meaning egg-shaped. These lie inclined, and sometimes almost horizontally, against the ground. The only other species of Geissorhiza in our area with similarly broad inclined leaves is Geissorhiza parva, a much smaller species with creamy-white flowers, both inside and out, whose petals are less than 8 mm long (G. ovata usually has petals over 10 mm long).
Geissorhiza ovata is a widespread and very variable species. Indeed, it probably includes more than one species or subspecies within its variation. At Phillipskop, most plants flower from August to early October, growing amongst the surrounding fynbos on well-drained stony ground. However, in late October and early November another form flowers – this time in the shady, overhanging rocks beside streams and waterfalls. Its different flowering time and very different habitat suggest that it may deserve recognition as a distinct species or subspecies, but as yet it has no name.
