Mammillaria canelensis is a comparatively new species, having been described somewhat incompletely by Dr. Craig in 1945.
Its salient features, summarised from the details given on page 308 of "The Mammillaria Handbook", are as followss-
Body simple globular; tubercles with milky sap set in 13 and 21 spirals .
Areoles with dense white wool in youth but soon becoming naked.
Axils with very dense white wool and numerous long white bristles .
Central spines 2-4, 30mm, long, heavy acicular, straight or somewhat curved, orange-yellow.
Radial spines 22-25, 5-15mm. long, very fine acicular, straight , white, horizontal.
Flowers, fruit and seed unknown.
Type locality Sierra Canelo. Distribution S.W. Chihuahua and S.E. Sonora.
More recently Backeberg (Die Cactaceae, Volume 5, p. 3414) given some floral data but, unfortunately, has not indicated if it was obtained from the original plants collected by Gentry, According to Backeberg the flowers are funnelform, 1.8cm. long and 1.5cm. in diameter. Both the outer and inner perianth segments are greenish yellow, the latterr being lanceolate and somewhat serrate. I am indebted to Mr. R.D. Ganiard, one of our Californian members, for the information that he has a very old plant which almost certainly is part of the Gentry material; this has divided dichotomously and bears yellow flowers. The 1955 catalogue of the Mexican dealer Schwarz refers to a form
or variety of M. canelensis with red flowers and, of recent years, seed of M. canelensis (red) and M. canelensis (yellow) has appeared on the lists of several nurserymen. As a result, plants of M. canelensis are often encountered in cultivation in Europe and the form with red flowers seems to be the more common of the two.
From "The Journal of the Mammillaria Society" - Vol.VIII n.3 June 1968
Mammillaria canelensis ROG 648
ROG 648 - 15.8km from Témoris - Chihuahua - Mexico
From a population in which the flower colour varies between yellow and red, with some orange.