#piaranthus

[ruthbancroftgarden]

Piaranthus geminatus

Stapeliads are a wonderful group of plants with succulent stems and starfish-like flowers, with many different genera and species found in Africa. This one is Piaranthus geminatus, from South Africa's Little Karoo region. It is a small plant, growing tucked under a rock, so most visitors pass by without noticing it. Stapeliads were traditionally put in the Milkweed Family (Asclepiadaceae), but now this whole family has been merged into the Dogbane Family (Apocynaceae). In the new naming system, the plants that had been placed in Asclepiadaceae are now placed in the subfamily Asclepiadoideae within the Apocynaceae.

-Brian

[wonder-rooms]

Robert Jacob Gordon (c. 1777-1786) 1. Milkweed, Piaranthus geminatus 2. Small Starfish Flower, Stapelia paniculata

[gamosepalous-5lobed]

Piaranthus decipiens

Photographed by: Maikel Gaitkoski

[ruthbancroftgarden]

Piaranthus geminatus

The stapeliads are a large group of stem-succulents that are related to the milkweeds. The milkweeds as a group used to have their own family (Asclepiadaceae), but they are now included within an expanded concept of the Dogbane Family (Apocynaceae). In whatever family they are placed, they are a remarkable group of many genera and hundreds of species with amazing starfish-like flowers. In many species, the flowers give off foul odors to attract flies, which serve as their pollinators. While 5 is the normal petal-count, it can be seen in the photos above that one of the flowers is a non-conformist with only 4 petals, or corolla lobes. The flower surface has a wonderful texture, as is often the case with the stapeliads. This species comes from South Africa's arid Little Karoo region, a treasure-house of succulent plants.

-Brian

[ruthbancroftgarden]

Piaranthus geminatus

This tiny plant is one of the many species of stapeliads, which are related to milkweed and now placed in the family Apocynaceae (formerly, the milkweeds had their own family, Asclepiadaceae). Visitors to the garden seldom even notice this plant unless it is in flower, with its attractive little pale yellow star-like flowers. Native to South Africa’s Eastern Cape and Western Cape provinces.

-Brian

[ruthbancroftgarden]

Piaranthus geminatus

The stapeliads are a large group in the subfamily Asclepiadoideae of the family Apocynaceae (previously, the subfamily was classified as a separate family, the Asclepiadaceae, but it was clearly closely related to the Apocynaceae and is now lumped into that family). The plant pictured is the diminutive Piaranthus geminatus, with its flowers looking like miniature yellow starfish. From South Africa’s Western Cape Province.

-Brian

[ruthbancroftgarden]

Piaranthus geminatus

Like Stapelia, Piaranthus belongs to the subfamily Asclepiadoideae within the family Apocynaceae. The 5-pointed starfish-like flowers are reminiscent of those found in Stapelia, but they are much smaller - less than an inch across (2.5 cm). Piaranthus geminatus has stems with chubby segments, and it is native to South Africa’s Little Karoo, as well as eastward into the Eastern Cape Province.

-Brian

[gamosepalous-5lobed]

Piaranthus geminatus

Photographed by: Noel Marais