Hemizygia transvaalensis is decorative, pleasantly aromatic and easy to grow. It is a multi-stemmed, long-lived, rounded herbaceous shrublet, 0.7 - 1 m tall with an equivalent spread. The rootstock is a lignotuber (perennial woody rootstock), which gives the plant the ability to survive and re-sprout after fires, and to re-sprout strongly after being pruned. The stems are angular, almost square, sparsely hairy, and stained purple on the younger growth. The leaves, arranged in opposite pairs, are sessile or with a short stalk, oval-elliptical to broadly oval, up to 40 mm long by 20 mm wide, rounded at the base and tapering to a sharp point. Both leaf surfaces are sparsely hairy and the margins are toothed like a saw. The leaves and stems are pleasantly aromatic and leave a slightly sticky residue on the fingers when touched. Its aromatic nature is a chemical defence against plant eating insects.

The striking inflorescence is a lax elongated terminal panicle to 200 mm long, branched once or twice at the base. The flowers are produced in whorls, each flower, salvia-like, with a tubular two-lipped corolla, ±22 mm long, with stamens exserted to ±10 mm, pale pink, lilac pink or almost white flushed with pink, protruding out of a persistent dark purplish-pink calyx. There are also persistent deep-pink floral bracts, up to 24 x 10 mm, produced with the last few whorls of flowers and at the tip of the inflorescence, and the stems of the inflorescence are coloured dark purple. The showy, multi-shaded purple and pink inflorescences are borne in profusion during spring and early summer (September to December) creating a conspicuous mound of colour. The seed is an ovoid, dwarf nutlet, and can be found in fours at the base of the calyx after the corolla has dropped off.

Hemizygia transvaalensis has a wide distribution in Mpumalanga from Pilgrims Rest in the north to Barberton in the south. It grows exposed in grassland on the Mpumalanga Drakensberg from about 100 m above sea level to an altitude of 1700 m. Rainfall is mainly during summer ranging between 700 and 1 750 mm per annum, and winters are dry with regular grass fires.

The sagebushes (Hemizygia species) are a very striking group of plants belonging to the sage and mint family (Lamiaceae). Many species have been tested for their potential as garden subjects and they are fast gaining popularity. The reason: their striking flowers and ease in cultivation.

The genus Hemizygia was first proposed by Bentham in 1884, but was only established in 1897 by Briquet. It was last revised by Dr Leslie Codd in 1976 and consists of ±35 species which occur mainly in Africa of which 28 species occur in southern Africa where they are found predominantly in the Northern Province and Mpumalanga but also in Gauteng, North-West, KwaZulu-Natal and the Eastern Cape, and in northern Namibia and Botswana. Of the southern African hemizygias, 16 species show promise as garden subjects.

The genus name Hemizygia is of Greek origin: 'hemi' meaning half and 'zygon', yoked or joined, referring to the two-lipped flowers. The species name transvaalensis means of / from or pertaining to the Transvaal and alludes to the province in South Africa where it was first collected. The Transvaal no longer exists as a province, it has been subdivided and renamed and is now the four northern provinces of South Africa: Mpumalanga, Gauteng, Northern Province and North-West Province. Hemizygia transvaalensis was first collected near Barberton (then Transvaal, now Mpumalanga) by Ernest Galpin (1858-1941) banker by profession, amateur botanist and plant collector, and was named in 1897 by Rudolf Schlechter (1872-1925), German botanist and traveller.

Growing Hemizygia transvaalensis

Hemizygia transvaalensis requires a sunny or semi-shaded position in nutrient-rich, well-drained, compost-enriched soil. It is well suited to the rockery and will do equally well in the mixed border. It can be grown as a solitary specimen, or in groups and is also effective when massed, planted roughly 60 cm apart. It is hardy to Highveld conditions (-5C / 23F / zone 9) but young plants should be protected from frost. It also does very well in the winter-rainfall Western Cape where it requires at least twice weekly watering during the dry summers. Once established, it is a long-lived perennial and can remain undisturbed for a very long time. For best results, Hemizygia transvaalensis should be pruned heavily in mid-winter. This will rejuvenate the plants, cause a flush of healthy new growth in spring and enhance flowering. An annual dressing of compost in late winter, and keeping them mulched will benefit the plants greatly.

Propagation is by cuttings or seed.
Hemizygia transvaalensis is readily propagated from softwood or herbaceous cuttings, best taken in spring or early summer. These should be about 50-100 mm long, with the lower leaves removed, planted in sand, or peat/finely milled bark and polystyrene mixture and best placed in a mist bed and kept moist. Rooting should be rapid (3 weeks) and after an approx. 2 week weaning period, the newly rooted plants should be grown on in light shade.
Seed can be sown in spring or summer, in a shallow standard seed tray in a standard well-drained seedling mix. Cover with a thin layer of sand (1-2 mm) and keep moist. Seed should germinate in 3-4 weeks. The seedlings can be planted out in individual bags as soon as they are large enough to handle.

References:

• Codd, L.E. 1976. The South African species of Hemizygia (Lamiaceae), Bothalia 12, 1: 1-20.
• Leistner, O.A. (ed.), 2000, Seed plants of southern Africa: families and genera, Strelitzia 10., National Botanical Institute, Pretoria

Ernst van Jaarsveld
Kirstenbosch
Oktober 2001