Curio ficoides (L.) P.V. Heath
Common names: blue chalkstick, flat-leaved senecio (Eng.); blouharpuis (Afr.)
A conspicuous, spreading, succulent shrub, with striking, large, bluish grey-green, elongated, flattish, succulent leaves, with a resinous smell when damaged. Known from the eastern Klein Karoo and Eastern Cape, growing on steep exposed mountain slopes and cliffs. Easily grown from cuttings, and best for dry warm gardens.
Curio ficoides is an ascending, multi-stemmed, evergreen, branched, shrubby succulent, 500–700 mm high, up to about 1 m tall and spreading 2–3 m in diameter. Branches brittle, rounded, succulent, woody below, often radiating from the main stem, the branch ends often reclining. The basal stems are greyish, often up to 20 mm diameter, bearing leaf scars; higher up, about 8–10 mm in diameter, herbaceous and easily broken, and with a resinous scent. Leaves and stems covered with a powdery bloom resulting in the attractive bluish to grey-green colour. The leaves are alternately arranged, about 5–20 mm apart, linear, sickle-shaped (falcate), tapering at both ends, ascending to ascending-spreading, about 80–150 mm (up to 210 mm) long, flattened (laterally compressed), 6–12 mm thick, to almost rounded 8–20 mm broad, and striated lengthwise, ending in a stiff, sharp point. The stripes are somewhat translucent. The basal stripe and upper stripe sometimes up to 1 mm wide, translucent.
The flowers are inconspicuous, produced at the ends of the branches, in subcorymbs with v-shaped branching, 100–180 mm long; the flowering stalk terete, 3–4 mm in diameter, the bracts narrow, 10–20 mm long at the base, becoming smaller upwards, 5–6 mm long. The capitula (composite flowers) about 6–12, each 12–15 mm long and 4–5 mm in diameter, rounded at the top (in full flower); ray florets absent; disc florets 9–12, white, the corolla lobes recurved; style and stigmas protruding, 2–3 mm, brownish purple.
Flowering is from autumn to winter, but sometimes at any time of the year.
Curio ficoides is widespread, plants are locally abundant and it is not threatened.
Distribution and habitat
Curio ficoides is confined to the eastern Klein Karoo in the Western Cape, occurring at Huisrivierpas, Badspoort and Meiringspoort, and also on the Baviaanskloof Mountains and further east to near East London in the Eastern Cape, usually confined to mountainous regions and river valleys and also at the coast at Mossel Bay in the Western Cape. The habitat consists of steep, exposed, rocky, sunny slopes, in Albany Thicket vegetation. It often grows in dense stands. The geology consists mainly of sandstones of the Cape Supergroup, but also Ecca Shale soils of the Karoo Supergroup.
Derivation of name and historical aspects
Curio ficoides was first described and illustrated in Caspar Commelin’s Horti medici Amstelodamensis in 1706, raised from seed sent by Van der Stel in 1702. This was the first Curio to have reached Europe. The earlier Pre Linnaean phrase name given to the plant was ‘Senecio Africanus arborescens, folia ficoidis’. It was also illustrated in 1727 (t. 49) by Richard Bradley in History of succulent plants. Linnaeus named his plant in 1753 as Cacalia ficoides. It was later transferred to Senecio, and ultimately by Paul. V. Heath (1950– ) in 1999 to the genus Curio. Curio was established by Heath in 1997 for a group of succulents, previously belonging to the very large genus Senecio. Diagnostic characteristics he used to separate it from Senecio are the evergreen nature, elongated, striated, succulent leaves and discoid flower heads lacking ray florets. The genus name Curio means ‘to lean’ pertaining to many species with a leaning or decumbent habitat, including Curio ficoides (Clark & Charters 2016). The specific epithet ficoides pertains to its resemblance to the family Mesembryanthemaceae. Prior to 1753, Mesembryanthemum was known as Ficoides.
Another synonym of Curio ficoides is Kleinia ficoides (L.) Haw., as described in Flora capensis. The succulent student Adrian Haworth transferred it to the genus Kleinia.
Curio ficoides is related to C. talinoides and C. crassulifolius. It is easily distinguished by its much more robust growth and flat, sickle-shaped leaves. C. talinoides has thin, terete, densely arranged softer leaves, and C. crassulifolius is a much smaller plant, without the reclining habit and with ascending terete leaves.
Curio ficoides is the largest, of about 20 known Curio species confined to South Africa. Some of these include C. acaulis, C. articulatus, C. archeri, C. citriformis, C. crassulifolius, C. herreanus, C. hallianus, C. radicans, C. rowleyanus, C. muirii, C. ovoideus, C. pondoensis, C. serpens, C. sulcicalyx, C. talinoides and C. toxotis. Of these species only C. ficoides, C. muirii, C. serpens, C. talinoides and C. pondoensis grow mainly on cliffs.
Curio ficoides grows on exposed steep slopes, often cliffs, the reclining stems rooting and forming new plants. The powdery bloom and bluish grey colour reflect the harsh sun and also act as a sun screen. The succulent nature enables the plant to survive periods of severe drought when the leaves becomes very thin, only to revive after a rain shower. At Meiringspoort (part of the Groot Swartberg), Curio ficoides grows on exposed slopes in Gamka Thicket. Associated plants include Aloe ferox and A. mitriformis, Lampranthus affinis, Ficus burtt-davyi, Cotyledon woodii, Crassula rupestris, C. pellucida subsp. marginalis and C. cultrata, Curio crassulifolius and C. muirii, Bulbine meiringii, Portulacaria afra and Senecio junceus.
Along the eastern portion of its distribution on shale cliffs along the lower Keiskamma, plants were found in Buffalo Thicket, sharing its habitat with plants such as Euphorbia triangularis, Caputia pyramidata, Adromsichus sphenophyllus, Crassula lactea, C. ovata and C. perforata, Aloe speciosa, Portulacaria afra, Olea europaea subsp. africana and Ehretia rigida. This form also with more slender, almost terete leaves.
The average annual rainfall in its habitat varies from 200–600 mm per annum and at an altitude of 200–800 m above sea level. Precipitation occurs mainly in the form of cold fronts in winter and thunder showers in summer. In its natural habitat, the stems often recline and are well-adapted to the steep slopes and cliffs where the plants grow.
Curio ficoides varies in leaf size, shape and colour. The most striking forms are those with the blue- to grey-green, sickle-shaped leaves. Towards the easternmost distribution, the author collected a form on cliffs of the Grootrivier Pass (Baviaanskloof Mountains) with long, rounded, terete leaves, up to about 200 mm long (see illustration above). This cultivar is named ‘Grootrivier’. Rowley in his book Succulent compositae (1994) reports a collection from Lavranos, near Laingsburg having short, fat, rounded (terete) leaves.
The cliff face is an ideal refuge, protecting the plants from larger herbivores. As with many associated succulents, branches which become detached, will root spontaneously when favourable conditions prevail (passive resistance).
The downy seeds are dispersed by wind and, with favourable conditions, seeds will germinate.
It is not known whether the plants are used medicinally. Rowley reports that the leaves are edible, however, it has not been recorded as edible or used by the indigenous peoples of South Africa.
Growing Curio ficoides
Curio ficoides is well established in the horticultural trade in Mediterranean-type climates of the world. This is because of its horticultural value: attractive and striking bluish, grey-green sickle-shaped leaves, drought tolerance and ease of growth.
Plants are easily propagated by stem cuttings and Rowley also reports its leaves can be rooted and new plants grown. Cuttings can be grown throughout the year where winters are not too severe. Cuttings of various length root rapidly in sand or even planted in situ. Plants are fast growing and will soon form shrubs.
It grows well in dry Mediterranean and Karoo gardens in regions where frost is not severe. It requires a sunny warm position and will tolerate very hot conditions and periods of drought. It is also easily grown in containers. Best planted on rockeries or steep embankments. It is especially attractive among cycads and other succulent companion plants. In South Africa it is best grown in thicket or Succulent Karoo gardens (Van Jaarsveld 2010). Curio ficoides can tolerate a wide range of soils, also mineral-poor, acidic, but must be well drained. Plants planted at Kirstenbosch National Botanical Garden and Babylonstoren out of doors (in a winter rainfall area), have also grown very successfully, and for years they have survived in the Matthews Rockery in Kirstenbosch, which has an annual rainfall of as much as 2 000 mm per annum, however, with well-drained soil. Plants will tolerate light frost, and will also grow well in seafront and coastal gardens.
- Clarke, H. & Charters, M. 2016. The illustrated dictionary of southern African plant names. Flora & Fauna Publications Trust, Jacana, Johannesburg.
- Eggli, U. (ed). 2001. Illustrated handbook of succulent plants: Dicotyledons. Springer, Berlin.
- Harvey, W.H. 1894. Compositae. In: W.H. Harvey & O.W. Sonder (eds), Flora capensis (Rubiaceae to Campanulaceae) III: 44–530. L. Reeve, Ashford.
- Heath, P.V. 1997. Three new generic names in Asteraceae (part 1). Calyx 5(4): 136, 137.
- Heath, P.V. 1999. Three new generic names in the Asteraceae (part 2). Calyx 6(2): 54, 55.
- Mucina, L. & Rutherford, M.C. (eds) 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.
- Rowley, G.D. 1994. Succulent compositae. Strawberry Press, Mill Valley, California.
- Van Jaarsveld, E.J. 2010. Water wise gardening. Struik, Cape Town.
- Vlok, J. & Schutte-Vlok, A. 2010. Plants of the Klein Karoo. Umdaus Press, Hatfield, Pretoria.
- Von Staden, L. 2012. Curio ficoides (L.) P.V.Heath. National Assessment: Red List of South African plants version 2015.1. Accessed on 2016/04/27.
Ernst van Jaarsveld
Kirstenbosch National Botanical Garden (Retired 2015)
Extraordinary senior lecturer and researcher,
Department of Biodiversity and Conservation, University of the Western Cape
Plant Type: Ground Cover, Scrambler, Succulent
SA Distribution: Eastern Cape, Western Cape
Soil type: Sandy, Loam
Flowering season: Autumn, Winter, Sporadic/All year
PH: Acid, Neutral
Flower colour: White, Cream
Aspect: Full Sun, Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Easy