The greater number of glands on the lower surface may be due to the limestone habitat of var. vinkii and var. brassii (plants of S. heterocarpus on limestone are densely glandular), also their short caudex. But there is no evidence that Ledermann's type did not grow on limestone. When more information is available it may be better to regard var. vinkii and var. brassii as representing a distinct species, for which Copeland's epithet strigosissimus would be available.