Notes on the reproductive behaviour of Anacampseros rufescens

While many of us enjoy the wild flowers we encounter in the field, we seldom are afforded the opportunity to observe all aspects of flowering through to seed dispersal.

Growing some of our wild flowers provides just such an opportunity, but sometimes this is not enough to see the full cycle. As an example, you may have observed that certain of the Iridaceae (Aristea or Moraea) flower only for a part of the day. In the grasslands of the Pondoland Centre of Endemism we often come across Aristea flowering brightly in the morning sunshine but these flowers are all closed when we return along the same route in the afternoon. In contrast we are always pleasantly surprised to see Moraea stricta suddenly appearing in the afternoon when there has been no sign of these flowers in the morning.

We have had the sun-loving succulent Anacampseros rufescens growing in a pot in our garden for some years. Generally in October, when this species tends to start flowering, we spend time on the verandah where we can see the plants in the pot.

Anacampseros rufescens in its natural habitat

The first year we saw a bud being produced, emerging from the unusual wiry white hairs between the rosette of basal leaves and waited avidly to see our first flower. Initially the bud stalk emerges horizontally. When we saw it start to become erect we were convinced that the flower was only a day or so from opening. However we were dismayed to see the fleshy bracts wither and fall away and leave an empty, papery capsule. It was only on subsequent flowering cycles that we realised what had happened.

Empty capsule (centre) and capsule with withered bracts peeling back (left)

Anacampseros rufescens is another of those plants with short-lived ephemeral flowers. They seem to open in mid-morning and by early afternoon those eye-catching bright magenta petals have withered, with only the bracts visible, looking very much like a bud.  This event very nicely coincided with our absence from our observation post and it took us some time to see all the stages from flowering to fruiting. It is only after the flower has been pollinated that the stalk becomes more erect.

As the seeds protected by the fleshy bracts mature, the bracts then themselves wither and drop away exposing the papery capsule in which the seeds are enclosed. Eventually the capsule splits slightly down the middle to expose the seeds to the wind – intriguingly, each seed is enclosed in a small fibrous bag not unlike a triangular tea-bag and the increased surface area provided by the bag allows the seeds to be dispersed by the wind.

Microscope view of Anacampseros rufescens seeds

Seed-filled capsule (centre)

The plant seems to have a very effective pollination process as there is no shortage of small Anacampseros rufescens coming up nearby. This species’ normal habitat is a rather harsh one, as it grows on rock plates near cliff edges. It copes surprisingly well with the hot dry conditions it is often exposed to. This is why we are grateful that it has grown so happily in the much more benign environment of the pot in our garden. We have enjoyed following its reproductive processes from start to finish. 

Early afternoon - petals starting to wither
Note wiry hairs at base of flower stalk