For the identification of insects and other fauna and flora of South Africa.

Wednesday, August 21, 2013

Beach Pumpkin (Arctotheca populifolia)

Family Asteraceae
Arctotheca populifolia is a 'beach bum'! It is a common pioneer along the southern African coast. Have a look next time you are on the beach and see if you can spot these obvious silvery grey-leaved colonies of plants on the foreshore dunes.
 Description

Arctotheca populifolia is an annual or perennial, creeping, mat-forming herb, up to 200 mm high. Leaves are large, heart-shaped with short stalks. They are slightly succulent with a dense covering of white hairs. The margins are smooth to shallowly dentate. The yellow flower heads are about 30 mm in diameter, borne on short, stout, curving stems and often overtopped by the large leaves. The green involucral bracts form a cup in several rows. The ray florets are bright yellow and widely spaced and the central flowers are greenish yellow.

Arctotheca populifolia generally flowers in the rainy season of any particular area, but because of the wide distribution, flowering times are recorded for all months of the year.

 Distribution and habitat

Arctotheca populifolia is common along the southern African coastline, from Hondeklipbaai along the West Coast right up to the southern Mozambique coast. It grows in deep sand on coastal dunes and around estuaries.

 Derivation of name and historical aspects

The genus name Arctotheca is derived from the Greek words arcto for bear, and theca for a case or capsule. The name refers to the densely woolly fruit. The specific epithet populifolia refers to the leaves, which resemble those of a poplar tree.

There are five species of the genus Arctotheca found in South Africa, namely: A. calendula, A. forbesiana, A. marginata, A. prostrata and A. populifolia.

Arctotheca calendula is known to be a strychnine antidote and a narcotic. It was also reported to have caused diarrhoea in sheep.

 Ecology

Flowers are pollinated by a variety of bees and flies. The parachute seeds are generally dispersed by wind but also remain viable in salt or fresh water and can therefore be dispersed by ocean currents.

 Uses and cultural aspects

Arctotheca populifolia is a strong, tough plant and valuable for holding sand; therefore very useful as a groundcover in coastal gardens and as a dune stabilizer. It can be planted for the attractive foliage rather than for the flowers. However, the flowers provide food and nectar to a variety of bees, flies, butterflies and moths and can bring insects into the garden.

It has been reported that the felt on the leaves can be useful as tinder to start a fire, if you are desperate to have a beach braai (barbecue).
Info: http://www.plantzafrica.com/