Cotyledon tomentosa

Family / Families: Crassulaceae
Scientific Name(s): Cotyledon tomentosa Harv.
Location(s): Berkeley, California, USA (cultivated)
Entry Author(s): Dominic Janus
Copyright Holder(s): John Rusk@Flickr
Image Permissions: Please contact the copyright holder for permission to use.
Photographer(s) Appreciation: This photo of Cotyledon tomentosa was shared by John Rusk (John Rusk@Flickr), many thanks!
Tags: Crassulaceae, Saxifragales, via Flickr

The flower of Cotyledon tomentosa

Today’s photo is the first appearance of the genus Cotyledon to Botany Photo of the Day. This is Cotyledon tomentosa, a widely-cultivated succulent. This plant was grown in California, far from the species’ native range in southern Africa.

Its common name of bear’s paw comes from the resemblance of the leaves to small, fuzzy bear paws. The resemblance is strengthened by the reddish teeth lining the tips of leaves, which suggest the claws of a bear.

Cotyledon presently consists of ten species with a number of varieties and cultivars. The genus previously incorporated four other now-separated genera, though there still remains some uncertainty around the taxonomy. The anagrammatic Tylecodon is one example of a genus that was formerly grouped under Cotyledon until 1978 (it contains approximately 50 species). In English, cotyledon refers to the small embryonic leaves of seedlings, but the genus name has Greek origins translating to “cup-shaped cavity”. This is a reference to the shapes of leaves in some Cotyledon species. The specific epithet, tomentosa, is a reference to the tomentose leaf hairs (“densely matted, soft white wool“).

Succulents describe any plants with thick, fleshy structures evolved to retain water in arid conditions. This water-storage capability, along with other adaptations such as small hairs that attenuate direct sunlight, can aid in surviving hot, dry summers. Bear’s paws are often recommended as plants to grow indoors or outdoors in dry, sunlit environments. Usually growing about as wide as it is tall, it typically reaches heights of 30-70 cm (~1-2 ft.). The leaves will typically reach around 5cm (2 in.) in length…significantly smaller than your average bear paw. Although a popular ornamental worldwide, its native range is restricted to rocky sites with well-drained soils, predominantly in the Cape Province in South Africa. One recognized subspecies, Cotyledon tomentosa subsp. ladismithiensis, grows larger and has longer, elliptically-shaped leaves. Some Cotyledon species can occur as far north as northeastern Africa, but about half are endemic to the Eastern and Western Capes of South Africa; the South African National Biodiversity Institute‘s website has details on many of the species.