Threatened Plant Species – Asclepias woodii

APOCYNACEAE: Asclepias woodii [Vulnerable]

“Local is lekker” which is why we love this month’s highlighted plant, Asclepias woodii, as it is only found in the KwaZulu-Natal midlands, and mainly centred on the town in Howick.

Asclepias woodii by Christeen Grant

Asclepias woodii are part of the Milkweed family, and they are a perennial herb. The stem is solitary, upright, up to 650 mm tall, often compressed, covered with scales or hairy scales. Leaves are usually in 4 pairs, growing upwards or almost upright, without or with short leaf stalk. Bracts are sharply pointed. Inflorescence produced in terminal pair.

Asclepias woodii flowers from November to January. Flowers 4−12, dark purple below. Leaf stalks 10−70 mm or when solitary up to 180 mm long, smooth to hairy. Corolla-lobes reflexed, spreading, egg-shaped, and pale green. Corona-lobes yellow, arising from the staminal column and equalling or slightly exceeding it, ending abruptly, rounded at the top and on the back.

It grows in unburned grassland, and it is threatened by habitat loss due to invasive alien plant infestation, frequent fires, overgrazing by livestock, and habitat loss due to plantations and development.

Photograph showing the entire plant, Asclepias woodii

If you have seen this plant, please contact Mbali Mkhize, CREW programme: KZN Node Project Assistant: m.mkhize@botanicalsociety.org.za

References:

• Brown, N.E. 1909. Flora capencis, Vol 4, 518.
• Nicholas, A. 1999. A taxonomic reassessment of the subtribe Asclepiadinae (Asclepiadaceae) in southern Africa Volume 1. PhD thesis. University of Natal, Durban

Threatened Plant Species – Asclepias concinna

APOCYNACEAE: Asclepias concinna [Vulnerable]

The Genus Asclepias is named after Aesculapius, immortalised as a god of medicine in ancient Greek mythology. This Genus once belonged to the family ASCLEPIADACEAE (milkweed/butterfly weed family), but after undergoing a recent revision by taxonomists, it is now classified as a sub-family within the APOCYNACEAE family. 

Asclepias concinna is a perennial herb found in the KwaZulu-Natal midlands to Maclear, in annually burnt Montane grassland. This plant is potentially threatened by afforestation and rural settlement. It grows to about 325 mm long, slender, sparsely leafy, and hairy.

Asclepias concinna photographed by Barbara Clulow

Leaves are upright, thin and hairy with short thin hairs, arrowing into a small petiole at the base with margins curled backwards and with short thin hairs.

Inflorescence umbel (usually a flat-topped inflorescence with the stalks arising more or less from a common point like an umbrella), adjacent to the base, stalked about 8 green and purple flowers.

Asclepias concinna flowers from October to December. Peduncle (lower unbranched stalk) upright, thin and with short thin hairs. Pedicels (stalk of individual flower) thread-like, half the length of the peduncle. Petals are compressed on the side towards the axis on which it is inserted, thin, short soft hairs; have woolly white hairs close to the edge of the side that faces away from the axis.

Sepals narrowly ovate and tapering to a point at the apex, sharp, with short thin hairs, half the length of the corolla. Corolla-lobes (second whorl of floral organs) egg-shaped to blunt, smooth with short thin hairs, margins with long soft, silky weak hairs. Corona-lobes (series of appendages on the corolla) white, smooth.

If you have seen this plant, please contact Mbali Mkhize, CREW programme: KZN Node Project Assistant m.mkhize@botanicalsociety.org.za

References:

• Brown, N.E. 1909. Asclepiadeae. In: W.T. Thiselton-Dyer (ed). Flora Capensis IV Section I (Vacciniaceae to Gentianeae):518-1036. Lovell Reeve & Co., Ltd., London. (Asclepias concinna (Schltr.) Schltr.)
• Nicholas, A. 1982. Taxonomic studies in Asclepias (Asclepiadeae) with particular reference to the narrow-leaved species in southern Africa. University of Natal.
• Nicholas, A., Scott-Shaw, C.R., von Staden, L. & Victor, J.E. 2006. Asclepias concinna (Schltr.) Schltr. National Assessment: Red List of South African Plants version 2015.1. Accessed on 2015/09/17

Rare Asclepias in Flower

On the regular Beacon Hill walk on the last Sunday of November, Eve Hughes was thrilled to discover eight Asclepias woodii plants in flower.  “I spotted them some distance away and wasn’t sure, but on closer investigation, Molly Perret and I were convinced.”  She called Gareth Boothway, Biodiversity Stewardship Manager for Midlands Conservancies Forum, to let him know.  He went up to see the plants and took this photo.

Asclepias woodii (Wood’s Asclepias), a member of the Milkweed family, is listed as Vulnerable in the SANBI Red Data List.  It is a  KZN Midlands endemic which reappeared on the hill recently after not being seen for nearly 100 years.

Kate Fennell, Friends of Beacon Hill committee member said “It’s always such a treat to find new things flowering on the Hill, especially a rarity such as Asclepias woodii“

This is an extract from a presentation Kate did on the plant recently:

How do Asclepiads attract pollinators?  Floral scent – Asclepiads produce a number of volatile compounds. A recent study identified between 15 – 57 compounds and a distinct scent profile for each species. Nectar is produced in small to moderate quantities.

How are the flowers adapted for pollination?   Inflorescences are dense and mechanically strong. Coronas are fat and fleshy and store nectar. Inside the cups are hairs (papilla) which are thought to secrete nectar. Pollinaria produce pollen in compact masses called pollinia. These have mechanical clips which attach them to pollinators.

What pollinates the plants? Chafer beetles. The beetles are agile, fast-flying and hairy. Importantly, they do not damage the flowers when feeding. Asclepiads with similar features share chafer pollinators. Because bees are uncommon in grasslands, chafers fulfil the role of large bees.

Join the regular Beacon Hill walk on the last Sunday of each month to see some of the 106 species of plants which flower in this special piece of grassland.

Contact Eve Hughes 082 872 4333

Biodiversity on Beacon Hill

To celebrate Heritage Day, Friends of the Howick Museum and Friends of Beacon Hill launched the Beacon Hill Flowers Photographic Exhibition at the uMngeni Howick Museum. 

Beneath gorgeous wildflower mobiles created by the Howick Pre-Primary School, Nic Ruddiman’s collection of Beacon Hill flowers is an absolute delight. Ranging from the rare and endangered to the simply beautiful, it is a celebration of this special place. Nic’s favourite pictures are of a Cyanotis speciosa and another of Pachycarpus concolor.

After an introduction to the importance of Natural Heritage by Claire Adderley, curator of the museum, there was an array of fascinating presentations about the biodiversity of the hill.  Claire emphasised the fact that, in future, the treasures of Beacon Hill may well be more important than the collections in the museum. Our role is to revere, respect, delight and protect our natural heritage, she added.

Botanist, Kate Fennell did a fascinating presentation on 6 plant species found on Beacon Hill, relating interesting stories about their rarity, names, pollination, adaptation to fire and medicinal use.  Most of the audience were surprised to hear how South African Dierama’s had been part of the Olympic Park flower garden created in London this year.Simon Joubert  talked about butterflies – which are good of the health of an environment.  He is convinced that the Blue Pansy and Painted Lady breed in this precious patch of grassland, while many others including the Pearl Charaxes pass through. Acrea males like to congregate on hilltops, so Beacon Hill is just perfect for them.Creating corridors for Biodiversity is crucial said Ingrid Nanni of SANBI – Early Detection Rapid Response Programme – so the link to Symmonds Lane Stream and down into Umgeni valley is of critical importance.  Other threats to the Midlands biodiversity (besides people, of course!) are invasive plants. In particular, Formosa lily, pom pom weed and St John’s Wort were mentioned.  105 indigenous flower species have been recorded, as well as 19 grasses, six tree species, 62 birds (including the endangered Grass Owl), 10 mammals and many butterflies. Among the rare plants found here is Asclepias wooddii, a KZN Midlands endemic which reappeared on the hill recently after not being seen for nearly 100 years.  Flowering time is usually December.

Beacon Hill is part of the Midlands Conservancies Forum Biodiversity Stewardship Programme and has been assessed as deserving of Protected Environment status.  Conservation of the area is important as it is one of the few remaining patches of Midlands Moist Mist belt Grassland. This status means that Howick residents will be able to continue to use the site for low impact, nature-based recreational and educational purposes, said Janis Holmes of Friends of Beacon Hill. Janis has been visiting the area for many years, enjoying the 360 degree views of the surrounding Midlands. The uMngeni Municipality, in particular Mayor Mbali Myeni, which owns the property is to be congratulated for their vision in setting aside this area for conservation. More importantly Beacon Hill will now have a management plan to ensure management appropriate to biodiversity conservation, supported by legal protection in terms of the Protected Areas Act. However, before the animals and wildflowers of Beacon Hill breathe a sigh of relief, it will still take time for the Protected Environment status and management plan to be implemented. The Friends of Beacon Hill have erected signs at the Lakeview Road and Curry’s Post Road entrances to the site emphasizing the prohibition of vehicular access to the hill and illegal dumping.  It is disturbing that these signs have been blatantly ignored by some members of the public. Trail bikes have been using the hill as a recreational track and 4 x 4’s with trailers have been driving onto the hill to dump refuse. Nesting francolins and rare ground orchids are some of the innocent victims of this disregard.

The public using the hill are asked to respect the conditions of its use, especially that it is to become a Protected Environment.  Join one of the regular walks on the last Sunday of every month, or explore on your own at any time.  For more information see: http://www.midlandsconservancies.org.za/membh.html