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Distribution (Map)
Populations of this variant of the Ariocarpus
retusus complex exist in several locations around Aramberri,
Nuevo Leon, populations to the north of Aramberri tend to be
predominantly white flowered, with occasional bicolored or pink
flowers, those to the west are virtually all deep pink
flowered.
Ariocarpus sp.
Aramberri, classical form of the
plant with deep pink flowers
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Comments
Plants of the Ariocarpus
retusus/trigonus complex in the Aramberri region are extremely
diverse in body form, and also in flower color. Morphologically the
plants can vary from the appearance of typical A. retusus to
typical A. trigonus, with a range of intermediates between
the two. The most interesting variation is in the flower color,
which can range from white through to deep pink, a color not found
in any other populations of A. retusus/trigonus. Bicolored
flowers also occur. The exact status of these plants is not fully
understood. A separate species, A. confusus, was erected by
Halda & Horacek in 1998 for the Aramberri plants, but given the
extreme variability of the population this would appear
premature.
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Anderson & Fitz Maurice in the
1997 review of Ariocarpus (Haseltonia
5) hypothesized that the population is the result of
hybridization between the two sub-species of A. retusus, the
meeting of the two being facilitated by the canyon which runs
through the Sierra in this area, this theory whilst accounting for
the morphological variation does not explain the pink flowered
plants. Cultivated hybrids between the two have so far failed to
produce other than the expected whit e/cream colored flowers as
illustrated here. An alternative theory on the origins of these plants
proposed by the author of this piece (J. Miller) is that the
population may represent an ancestral form of both A.
retusus and A. trigonus, migration to the east having
resulted in A. trigonus, whilst migration into the
higher ground to the west has resulted in A.
retusus.
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Ariocarpus sp.
Aramberri, form with bicolored
flowers
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An
artificial hybrid of A. retusus x A. trigonus with
characteristics intermediate between the two
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Flower color in Ariocarpus species, with
the exception of A. retusus/trigonus is pink with an
occasional white variant. a factor which is taken as further
evidence of the more primitive nature of the pink flowered plants,
white/yellow flowers would appear to be derivative of pink. If the
ancestral form theory is correct it gives further support to the
unification of A. retusus and A. trigonus as
one species, by providing a common ancestor for both forms. It
may, of course, be that these plants represent no more than an
extremely genetically diverse population of A. retusus. Much
more study will be needed before the taxonomic problems posed by
the Aramberri populations are fully resolved.
Field
Numbers
A full
listing of all associated field data can be found on our field number reference pages, some associated
numbers include:.SB1426,
LH470, LH471, PP 416,
PP420, PP421, PP581, PP585, PP957
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