Extrafloral nectary glands

All Coryphanthas have the potential to produce extrafloral nectary glands. Two different types must be differentiated (see Plate 2, photos 1-4):

• Species in which nectary glands are always present, either in the areolar groove and/or in the axil (subgenus Neocoryphantha)

• Species with optional nectary glands around the flowering period only, and directly behind the spine-bearing areole only and, moreover, on singular areoles only (subgenus Coryphantha). Among them, there are species which were counted among the obligatory gland-bearing Coryphanthas by earlier authors (BACKEBERG 1961, H. BRAVO 1991; e.g. C. pseudechinus ssp. pseudechinus, C. pulleineana etc.) as well as other species which until today have been regarded as glandless (e.g. C. pseude-chinus ssp. laui, C. maiz-tablasensis etc.).

The differentiation between obligatory and optionally gland-bearing Coryphanthas can already be observed in a seedling only a few weeks old, because the species mainly of the series Clavatae and section Ottonis, which will be gland-bearing later on, show strikingly "inflated" and flattened, snow-white small spines, while the first spines of the non-glandular species are much thinner, roundish and yellow-brown (see Plate 4).

Only when considering these three points mentioned above can plants of this genus be judged and classified correctly. Disregard of these points has led to wrong diagnoses in the past and contributed to the general systematic chaos.

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