Empodium veratrifolium
Introduction
The bright yellow West Coast star appears after the first good autumn rains, at a time when few other geophytes are in flower. It is easily grown in pots, or in sunny or partially shaded rockeries that are kept dry in summer.
Fig. 1. Star-shaped flower of Empodium veratrifolium.
Description
Description
Empodium veratrifolium is a winter-growing geophyte that grows from an often deep-seated, flattened, white corm surrounded by layers of blackish, fibrous outer tunics. There are 3 to 6 broadly lance-shaped, bright green, curved leaves that are strongly pleated, and fully developed at flowering. The leaf bases are surrounded by several blackish cataphylls (sheaths) that hold the leaf bases in place.
Fig. 2. Empodium veratrifolium has white corms surrounded by blackish tunics and blackish sheaths around the bases of the leaves.
The bright yellow, star-shaped flowers are about 50 mm across, and comprise 3 outer and 3 inner, elliptical tepals, with greenish undersides. The outer tepals are broader than the inner ones. A single flower is produced per pedicel (flower stalk) but several flowers are produced per corm. The flowers have 6 stamens, with prominent, narrow, suberect, yellow anthers. The central, erect style has three stigmatic lobes and is held below the level of the anthers. The long, narrow ovary is inferior (attached below the stamens) and is produced well above ground level, atop a very long and narrow, 3-sided pedicel that is 10–15 mm long. Each flower lasts up to 7 days. The narrow fruit has a very short beak and is fragrant and fleshy. It disintegrates when ripe, releasing small, black, shiny seeds. Flowering time is late April to late June (late autumn to mid-winter), but mainly in May.
Fig. 3. Empodium veratrifolium flowers have a very long, narrow pedicel.
Conservation Status
Status
Empodium veratrifolium is a threatened species and its current conservation status is listed as Endangered (EN). This is mainly because of loss of habitat due to housing development. Fewer than 15 small, highly fragmented existing populations are known, and these are also at risk from encroaching alien vegetation and pollution, such as dumping of rubble from construction sites.
Fig. 4. Empodium veratrifolium in habitat, growing in granitic gravel.
Distribution and habitat
Distribution description
The natural distribution of Empodium veratrifolium is confined to coastal parts of the Western Cape from Lambert’s Bay in the north to the Darling area in the south. It experiences a mild, winter rainfall climate with no frost, and hot, dry summers. The plants are almost always associated with granite outcrops, often occurring in dense colonies in fertile loamy soil and granitic gravel between boulder crevices. Occasionally they also occur on calcrete outcrops in sandy, stony soil, or rarely on shale. They mostly prefer light to deep shade, but sometimes grow in full sun. They are encountered in four vegetation types: Lambert’s Bay Strandveld, Langebaan Dune Strandveld, Saldanha Flats Strandveld, Saldanha Granite Strandveld and Swartland Shale Renosterveld.
Fig. 5. Empodium veratrifolium in habitat, showing the pleated leaves.
Derivation of name and historical aspects
History
Empodium is derived from the Greek words em, meaning ‘within’, and pous, meaning ‘foot’, with reference to the ovary of certain species that is located underground, as in E. namaquensis. The specific name veratrifolium is derived from the Latin words vera meaning ‘true’ and trifolium, meaning ‘three-leaved’ and refers to the usually three true leaves produced by each adult corm. The flowers and leaves of E. plicatum are similar to those of E. veratrifolium but the former differs in having a subterranean ovary, leaves that are absent or just emerging at flowering time, and it has a much wider distribution from Namaqualand to the southern Cape, and always grows on open flats in full sun.
The genus Empodium was created by the British botanist R.A. Salisbury in his book The Genera of Plants in 1866, however E. veratrifolium had previously been described as Hypoxis veratrifolia by the German botanist C.L. Willdenow in his book Species Plantarum in 1799. Subsequent authors transferred the species to the genus Curculigo in 1878 and to Forbesia in 1914, and it was finally placed in Empodium in the Journal of South African Botany in 1972 by the botanist M.F. Thompson (1941-1982), a staff member of the former Botanical Research Institute at Stellenbosch. There are six other species of Empodium that include E. elongatum from the Free State, Gauteng, KwaZulu-Natal and Mpumalanga; E. flexile from the Northern, Western and Eastern Cape, E. gloriosum from the Western and Eastern Cape, E. monophyllum from KwaZulu-Natal, and E. namaquensis and E. plicatum, both from the Northern and Western Cape.
In addition to Empodium, the family Hypoxidaceae comprises six other genera: Curculigo, Hypoxis, Hypoxidia, Molineria, Pauridia and Rhodohypoxis. Pauridia and the horticulturally outstanding Rhodohypoxis are endemic to southern Africa. The medicinally important Hypoxis, by far the largest genus with about 100 species, has an almost cosmopolitan distribution and is centred in sub-Saharan Africa, especially in southern Africa, but is notably absent from Europe. Curculigo occurs in Africa, Asia and Australia, Hypoxidia (one species) is endemic to the Seychelles, and Molineria occurs in southern Asia and Australia.
Fig. 6. Empodium veratrifolium in habitat, growing in crevices between granite boulders.
Ecology
Ecology
Empodium veratrifolium is a deciduous geophyte with a winter-growing, summer-dormant life cycle. The corms are often deeply wedged between boulder crevices to prevent being eaten by porcupines. The flowers open on warm, sunny days, as well as in cold, cloudy or rainy weather, and close towards late evening and at night. Bees and various small beetles visit the flowers in search of pollen. After flowering, the pedicels arch toward ground level, where the fleshy fruits disintegrate and the seeds are released close to the mother plants. The fruits are fragrant, perhaps to attract animal vectors to aid in their dispersal. The adult corm is replaced every year by a new one that develops during the winter growing season. The upper parts of the leaves are sometimes grazed by rock rabbits (dassies) in their natural habitats.
Fig. 7. The developing fleshy fruits of Empodium veratrifolium.
Uses
Use
This species has no medicinal or magical uses, but it is occasionally used as a container plant by specialist growers of cormous plants.
Growing Empodium veratrifolium
Grow
The deciduous nature of Empodium veratrifolium and its sensitivity to moisture in summer, renders this species more suitable to cultivation as a container plant than as a general garden subject. Plant the corms in frost-free areas in deep containers (at least 150 mm deep) in early autumn, using a sharply drained growing medium such as two parts course river sand or grit, and one part well-decomposed, finely sifted compost or finely milled bark. Plant the corms 30 to 50 mm deep (they may frequently pull themselves more deeply) and apply a heavy water drench. Once the leaves appear, provide a weekly heavy drench until late spring, then cease watering altogether until the following autumn. In areas of high winter rainfall, place containers beneath a covered patio, where the plants will receive morning sun and afternoon shade, or morning shade and afternoon sun. Where garden irrigation does not take place in summer, and porcupines and mole rats are not prevalent, corms can be grown in rock garden pockets, inter-planted with low-growing annuals like Cleretum bellidiforme (Bokbaaivygies) and perennial succulents like Jordaaniella dubia (matvygie).
Propagation is by seed, and separation of corm offsets. Separate corm offsets in late summer and replant immediately. Harvest the seeds just before the fleshy fruits disintegrate in mid- to late winter, and sow immediately in pots, in the same medium recommended for mature corms. Sow the seeds thinly and cover lightly with 2 mm of sowing medium. Water thoroughly every few days using a watering can fitted with a fine rose-cap and cease watering once the seedling leaves start to turn yellow in early summer.
The corms are sometimes attacked by mealybugs and are also subject to fungal rotting if kept wet in summer, but generally the plants are pest- and disease-free.
References
- Du PLessis, N.M. & Duncan, G.D. 1989. Bulbous plants of southern Africa. Tafelberg, Cape Town.
- Duncan, G.D. 2010. Grow bulbs. Kirstenbosch Gardening Series. South African National Biodiversity Institute, Cape Town.
- Helme, N.A. & Raimondo, D. 2005. Empodium veratrifolium (Willd.) M.F.Thomps. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2023/05/17.
- Johnston, M. 2022. Observation of Empodium veratrifolium, Langebaan, Western Cape. iNaturalist. Online. https://www.inaturalist.org/observations/126661952.
- Mason, H. & Du Plessis, E. 1972. Western Cape Sandveld Flowers. Struik Publishers, Cape Town.
- Mucina, L. & Rutherford, M.C. (eds) 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.
- Nordal, I. 1998. Hypoxidaceae. In Kubitzki, K. (ed.), The families and genera of flowering plants vol. 3. Springer, Berlin, Heidelberg.
- Snijman, D & Singh, Y. 2006. Hypoxidaceae. In: Germishuizen, G., Meyer, N., Steenkamp, Y. and Keith, M. (eds). A Checklist of South African Plants. South African Botanical Diversity Network Report No. 41, Pretoria.
- Thompson, M.F. 1972. Notes on Empodium and a new species of Pauridia. Journal of South African Botany 38: 163–164.
- Wiland-Szymanska, J. 2001. The genus Hypoxis (Hypoxidaceae) in Central Africa. Annals of the Missouri Botanical Garden 88: 302–350.
Credits
Graham Duncan
Kirstenbosch National Botanical Garden
October 2023
Plant Attributes:
Plant Type: Bulb
SA Distribution: Western Cape
Soil type: Loam
Flowering season: Autumn, Winter
PH: Acid, Alkaline
Flower colour: Yellow
Aspect: Shade, Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Average
Special Features:
Good potplant
Horticultural zones
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