Trichodiadema pygmaeum is a lovely dwarf succulent shrub with pretty pink flowers and hairy leaves. It is suitable for growing in a rockery and since it is a tiny clump-forming succulent it is perfect to grow in a pot as well.
Trichodiadema pygmaeum is a semi-prostrate, mat-forming, compact dwarf succulent shrub up to 30 mm high. The leaves are oblong and semicircular and covered with distinct hair-like bristles. The flowers are pink, solitary, with short pedicels, up to ± 20 mm in diameter, without bracts. Flowers have no filamentous staminodes. Seeds of the genus are pear-shaped, minutely warty and grooved, brown or yellowish. It f lowers from winter to early summer. A distinguishing characteristic of the genus is the crown (diadem) of hairs on the leaf tips. However, T. pygmaeum has no proper diadems.
It is recorded as VULNERABLE on the South African Red Data list.
Distribution and habitat
The species occurs in South Africa, in the Western Cape near Swellendam in Renosterveld vegetation. The genus has a wider distribution range in Namibia, western Free State, Western, Northern and Eastern Cape. It therefore occurs in both winter and summer rainfall regions.
Derivation of name and historical aspects
The genus name is derived from the Greek words trix meaning hair and diadema meaning crown. It refers to the tuft of hair-like bristles borne on the leaf tips.
The species epithet pygmaeum refers to the dwarf size of the plant.
There are 32 species in the genus. They are widespread in the more arid areas of South Africa and in southern Namibia.
The plants have fibrous roots which enable them to survive drought. Possible pollinators are bees.
Uses and cultural aspects
The genus is occasionally cultivated. It is browsed by stock.
Growing Trichodiadema pygmaeum
Plants can be grown from seed. Sow seeds in plastic seed trays in autumn. Make sure the trays are adequately drained. Use a mixture of 2 parts sand, 1 part loam and 1 part compost. Sow the seeds on top of the surface and cover them with a 1mm layer of coarse river sand. If sown too deep the seeds will be smothered and will probably not germinate. Water with a fine mist spray every second day. Place seed trays in a sunny position. Plant the seedlings out when plants are strong enough to handle.
It can also be propagated from cuttings. Use new, soft material from a healthy bush. Take tip cuttings in autumn. Place cuttings in sand in multi plug trays. A rooting hormone can be added to promote root growth. Ensure that the cutting medium is kept moist. Cuttings can be hardened off for 2–3 weeks and can then be transplanted. Plants can be cultivated in pots or planted in groups in the garden in a well drained, sunny area. They can also be used in rockeries. Other succulents such as Gibbaeum, Lithops, Stomatium and other small succulents can be planted alongside to make an attractive display.
References and further reading
- Brown, N. & Duncan, G. 2006. Grow Fynbos plants. National Botanical Institute, Cape Town.
- Germishuizen, G. & Meyer, N.L. (eds). 2003. Plants of southern Africa: an annotated checklist. Strelitzia 14. National Botanical Institute, Pretoria.
- Goldblatt, P. & Manning, J.C. 2000. Cape plants. A conspectus of the Cape flora of South Africa. Strelitzia 9. National Botanical Institute, Pretoria, & Missouri Botanical Garden Press, St Louis.
- Herre, H. 1971. Genera of the Mesembryanthemaceae. Tafelberg, Cape Town.
- Leistner, O.A. (ed.). 2000. Seeds plants of southern Africa: families and genera. Strelitzia 10. National Botanical Institute, Pretoria.
- Smith, G.F., Chesselet, P. Van Jaarsveld, E.J., Hartmann, H., Hammer, S., Van Wyk, B-E., Burgoyne, P., Klak, C., Kurzweil, H. Mesembs of the world. Briza, Pretoria.Van Jaarsveld, E.J. & De Villiers-Pienaar, U. 2000. Vygies gems of the veld. Grafica Quadro, Tradate (VA) Italy.
Author: Olivia Tyambetyu
Millennium Seed Bank