rebutia_albiflora_ritter_and_buinning

Rebutia albiflora Ritter & Buinning

By Aymeric de Barmon, 1998/11/23.

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This species was discovered at the beginning of the sixties in the Pilaya area near Nogales in southeast Bolivia. Among Rebutia of the close vicinity I noted :

  • R. pulvinosa (FR 766)
  • R. pilayensis (KK863) = R. nogalensis
  • R. gibbulosa (KK1563)
  • R. albiflora (FR766a & KK1956).

The plants had been very little collected at the type locality and not at all elsewhere. Only Ritter and Knize had been able to add it to their field collection list. Worth to be noted is the fact that this has not been achieved by Rausch, Lau nor Hillmann. Curiously the plants had not been noticed for their differences when Ritter collected them, they were mixed with R. pulvinosa. Both taxons are not exactly sympatric : R. albiflora grows at a slightly lower altitude than R. pulvinosa.

In collections I never saw material documented FR766a nor KK 1956. Bearing in mind that the specie is in cultivation since it's initial discovery and the new fashion for documented material, it seems that all we have in cultivation is from Ritter.

That's where the issue is coming from. FR766a is a number which seems to indicate that there was very little original material (plants or seeds ?). What we commonly see in cultivation fully fulfill the original description and is easy to identify. What is more, these plants are all self-sterile and despite all my attempts to cross-pollinate plants of widely different sources fruit setting usually does not occurs. Maybe do we have only one clone in collections. After 6 years of vain attempts a fruit isolatedly sets ! It contains 4 seeds. Although all the usual care had been taken, a doubt surrounded the non-hybrid origin of the seeds (most Rebutia flower together in May…).

This doubt will be there until the first flowers to appears. Body features is not a readily way to identify the specie. R. albiflora is very responsive to it's surrounding and exhibit a highly polymorphism depending on the plant age, food available and sun. Young plants well nutrished in a rather shady place grows short cylindrical clumps of variable size heads. Old plants with less space available presents flat clumps of small rounded heads closely tied together. When this kind of clumps are sun-burned, recovery is only from new heads which appears on the shoulders.

Let's go back to the 4 seeds. They produced 2 healthy seedlings. As expected they are unlike any of both forms previously described ! The major difference was a well spined and elongated apex although on the mother (father ?) plant it is almost naked and flat.

18 months after sowing we are in May '98, and the first flowers are opening. Good news : they are identical to those on the mother plant. Other good news : seedling body is becoming what it was expected to be (see above the young plants features) they also begins to clump. Hybrid origin is now discarded.

First flowers from these 2 new clones allows me to observe fruit setting on R. albiflora. Fruits are red when not ripe (can lead to bad harvesting attempts !) and dried when ripe. Harvesting occurs in July. Fruits contains few seeds(max = 7, min = 1), germination rate is also low (<50 %) 10 days after sowing (after that nothing occurs).

Unlike other Rebutia, among which R. pulvinosa, R. albiflora is very soil-tolerant, it grows equally well in organic mixes and in purely mineral ones. In that kind of growing medium R. pulvinosa, R. muscula, R. ithyacantha, R. albopectinata, R. schatzliana, R. verebii and others shows a trend for a yellow apex to appear although roots are abundant and perfectly healthy, it is highly likely to be an instance of a special weakness for a disease to appear.

I am very interested in all the information that Au Cactus Francophone readers could bring on all Rebutia, and especially on R. albiflora.

Thanks in advance !

Author : Aymeric de Barmon.
Published: 1998/11/23.
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