the genus rebutia 1895—1981 - Free

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In proposing the following arrangement we realise that whatever scheme we
propose it will not be universally accepted. We have not slavishly followed any one
particular system but have attempted to amalgamate the best of a number of different
arrangements. One of the criteria we have used is the breeding system, i.e. whether a
species is self sterile or self fertile. This neatly divides the Section IV Rebutia into two
workable subsections. It also divides the large Backeberg genus Mediolobivia into
two distinct sections, Section II Mediolobivia and Section III Digitorebutia. There will
always be a problem with those plants which bridge the gap between the different
sections (being neither wholly self fertile, nor wholly self sterile), but we believe that
ours is the most workable scheme to date.
The following is an attempt at producing a description for the whole genus and is
based on Buxbaum (1958).
Rebutia K. Sch. emend Buining & Donald.
Dwarf, globular or slightly cylindrical plants usually making offshoots from the base.
Tubercles often distinct, spirally arranged and sometimes formed into distinct ribs.
Spines very variable in length and colour; sometimes short, stiff and bristle-like but
often long and flexuous. Flowers always produced from old areoles, usually
appearing crowded at the base and very large in relation to the size of the plant. The
flowers are brilliantly coloured, red, yellow, purple and occasionally white,
campanulate or funnel-shaped. The receptacular scales are sometimes naked but in
others with copious hairs and bristles. Stamens are produced from the funnel part of
the flower never from a ring in the throat. Occasionally the style is united to the
receptacle wall. The fruit is a small capsule which opens by a circular split so that the
lower half which remains on the plant is like a shallow bowl in which some of the
seeds remain. Seeds small, black and shining but also dull and earth coloured in
some species.
Classification of the genus Rebutia
Rebutia K. Sch. emend. Buining & Donald Type species Rebutia minuscula K. Sch.
Section I Aylostera (type Rebutia deminuta (Web.) Br. & R.)
Section II Mediolobivia (type Rebutia aureiflora Backbg.)
Subsection I Setirebutiae
Subsection II Cylindrorebutiae
Section III Digitorebutia (type Rebutia pygmaea (R. E. Fries) Br. & R.)
Subsection I Pygmaeae
Subsection II Euanthemae
Section IV Rebutia (type Rebutia minuscula K. Sch.)
Subsection I Rebutiae
Subsection II Mediorebutiae
Lists of the species which belong to a particular Section or Subsection, together with
distribution maps and locational data, are given in the chapter devoted to
geographical distribution.
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