Pycnostachys urticifolia is an evergreen, aromatic, perennial shrub, with beautiful dark blue flowers, which bloom very late in autumn. The species is a good choice for an informal garden.
Pycnostachys urticifolia is a herbaceous perennial, 1–2.5 m high. The leaves are densely covered with hairs; broad and almost triangular, margins of leaf with rounded teeth, becoming smaller near the top. The stem is branched especially towards the tip. The flowers, which are arranged in spikes at the tips of the branches, range from mauve to dark blue. As the flowers drop, the spikes develop sharp reddish spines at the base, which remain on the bush for many months. It flowers very late in autumn, from about April until June. It is seen at its best in warm places, such as Pietermaritzburg in KwaZulu-Natal, for it is often cut back by frost just as it commences flowering in cold places such as Johannesburg.
The plant grows naturally in most parts of the country and is therefore not protected.
Distribution and habitat
Pycnostachys urticifolia occurs naturally in South Africa. It is found in Gauteng, Mpumalanga, KwaZulu-Natal, Kentani (correctly pronounced as kuCentani ) in the Eastern Cape and extends to Swaziland, Zimbabwe and Malawi. The hedgehog sage occurs in grassland and bushveld areas, usually in marshy places, along stream banks or forest margins.
There are 3 Pycnostachys species that occur in South Africa, namely P. coerulea, P. reticulata and P. holophylla, and about 37 species that occur in tropical Africa. P. stuhlmannii grows in Malawi, with bright blue flowers and narrow leaves.
Derivation of name and historical aspects
The genus name Pycnostachys is derived from the Greek word, pyknos, meaning dense, and stachys, meaning an ear of corn or a spike; referring to the dense flower spikes. The species name urticifolia means nettle-like leaves, referring to the leaves that resemble a species of the true nettle, Urtica.
Pycnostachys urticifolia is food for grasshoppers and the flowers are visited by bees and butterflies.
Uses and cultural aspects
The hedgehog sage is an aromatic perennial. Despite its attractive appearance, the species is poorly known in horticulture and there is no evidence that it has been used medicinally.
Growing Pycnostachys urticifolia
Pycnostachys urticifolia forms a large bush and is suitable for the back of an informal border. The hedgehog sage requires a warm, sheltered position in cold areas and it grows well in the open sun as well as in partial shade in ordinary garden soil. The plant is propagated by seed sown in spring or early summer or cuttings taken in spring or early summer.
References and further reading
- Eliovson, S. 1980. Wild flowers of southern Africa. How to grow and identify them, edn 6. Dai Nippon Printing, Hong Kong.
- Jackson, W.P.U. 1990. Origins and meanings of names of South African plant genera. University of Cape Town Printing Department.
- Van Wyk, A.E. 2000. A photographic guide to wild flowers of South Africa. Struik, Cape Town.
- website: http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=149720.
Walter Sisulu National Botanical Garden