The name in the genus's history
The currently accepted name is Maihueniopsis clavarioides (Puna clavarioides in Stuppy's paper). The habit of these small geophytic plants led to comparisons with Tephrocactus bonnieae, formerly described in Puna. Seed analysis revealed significant differences between the plants. [2-WWW] [Stuppy 2001]
Seed covering and embryo
In M. clavarioides, the outer layer of the covering derived from the ovule's funiculus consists of long, strongly flattened, unicellular hairs. Beneath it are elongated, thick-walled cells in a fibrous arrangement. The embryo is curved almost into a ring. [Stuppy 2001]
In T. bonnieae, the same region has a smooth surface and abundant tissue with cells containing air spaces, and the embryo is bent into a hook. The comparison shows how traits hidden in the seed can separate plants with similar habits. The current placement of the two species can be compared in the profile of T. bonnieae. [Stuppy 2001]
Synonyms and names in the literature
Austrocylindropuntia clavarioides · Austrocylindropuntia clavarioides var. ruiz-lealii · Cereus clavarioides · Cereus sericeus · Cylindropuntia clavarioides · Opuntia clavarioides · Opuntia clavarioides f. cristata · Opuntia clavarioides var. ruiz-lealii · Opuntia microthele · Opuntia ruiz-lealii · Puna clavarioides · Puna clavarioides f. cristata · Tephrocactus clavarioides [2-WWW]