Gasteria croucheri (Hook.f.) Baker
Common names: forest gasteria, forest ox-tongue, Natal gasteria (Eng.); bosaalwee, oukossies, Natal beestong (Afr.); impundu, iqhomololo (isiZulu)
Gasteria are popular indoor, succulent, aloe-like plants and are easily grown. They are mainly from South Africa (one species just entering southern Namibia) and the greatest concentration occurs in the thicket vegetation of the Eastern Cape. The flowers are nectar-rich and edible.
Gasteria croucheri is a solitary or cluster-forming plant, up to 400 mm high, with ascending, spreading leaves. It sometimes forms small clusters of up to 8 individuals or more. The leaves occur in opposite rows or rosettes, are tapering, strap-shaped, 200-360 mm long, and 30-100 mm broad at the base, with a smooth but mottled skin (epidermis), the top rounded with a short, pointed mucro. The leaves in young plants are always opposite (distichous), some are rough (tuberculate) and look quite different to the smooth adult leaves.
The flowers are borne on a spreading, flat-topped panicle (flower stalk), 500 mm tall, which is a simple raceme when young. Its tubular flowers are 28-50 mm long. The fruit capsule is 18-25 mm long. Flowering time is from late spring to summer.
According to the Red List of South African Plants, Gasteria croucheri is assessed as Vulnerable (VU). Over the past 30-40 years, or three generations, it has lost 30% of its mature individuals and the decline is ongoing because plants are continually being harvested for the traditional medicine markets.
Distribution and habitat
Gasteria croucheri has a wide distribution from the Mzimvubu River in the Eastern Cape to Durban in central KwaZulu-Natal. It is mainly confined to cliff faces, growing in quartzitic sandstone rock formations (rarely on shale), also on rocky outcrops among leaf litter in subtropical shrub forest adjacent to the river valleys. The climate is moderate, without frost, and hot and humid during summers. Rainfall is mainly during the warmer summer months ranging between 1 000 to 1 250 mm per annum. Winters are dry but with the occasional cold fronts and ample winter rain.
Derivation of name and historical aspects
Gasteria croucheri was first collected and introduced into cultivation by Thomas Cooper in 1860. It was named by Hooker in 1880. In 1869 he had described it as Aloe croucheri in Curtis's Botanical Journal stating, "This, the handsomest Gasteria of the kind that has hitherto flowered at Kew, is named after the intelligent foreman of the propagating department, Mr Croucher, under whose care the succulent plants of the Royal Garden are placed, and to whose zeal and special love for this class of plant the collection owes much of its value and interest."
Gasteria not only looks aloe-like but also belongs to the Aloe family, Aloaceae. It is immediately differentiated from other members of this family (Aloe, Haworthia, Astroloba, Poellnitzia) by its pendent flower stalks and tummy-shaped (gasteriform), pendent flowers.
Gasteria croucheri, like all the other gasterias, has tubular flowers rich in nectar, pollinated by sunbirds.
Most Gasteria species thrive in cultivation, both indoors and outdoors. In Gasteria bicolor var. liliputatana, it was mentioned that some are used for medicinal purposes and G. croucheri is a popular plant in KwaZulu-Natal. The plants are sometimes placed on the roofs of dwellings in the Eastern Cape, with the belief that the lightning will not strike the house. The Zulu people use parts of the plants in faction fights, believing that it will make them partly camouflaged so the enemy will not see them.
Growing Gasteria croucheri
Gasteria croucheri grows well as a pot or container plant on windowsills, verandas or in rocky, succulent gardens. The plants prefer partial or dappled shade. They are tolerant towards other plant species and often share their habitat with other smaller succulent plants. They thrive well on any organic feeding. The plants are not frost-tolerant but would survive light frost. Plant on the shady side of rocks or below shrubs. It can grow in a wide range of soil and also even grows well in the winter rainfall Western Cape gardens where it should be moistened during the dry summer months. It can be divided at any time of the year. Gasterias are fairly pest free, and may occasionally be attacked by the Aloe snout weevil. Overwatering will also lead to fungal infections and rot. Another attractive species to be consider for cultivation is Gasteria polita.
Gasteria croucheri is easily propagated from division, leaf cuttings or seed. Seed can be sown during spring or summer. In cultivation, Gasteria flowers must be cross pollinated to produce seed. Capsules soon abort when not pollinated. .Sow in a sandy, well-drained potting soil in a warm, shady position in standard seed trays. Germination is within three weeks and the seedlings are slow growing. Cover with a thin layer of sand (1-2 mm), keep moist and the seedlings can be planted out in individual bags as soon as they are large enough to handle. Flowering occurs within 3-4 years. Leaves can also be placed in potting soil. After removing the leaf, let it lie for about one month in order to heal. Lay it on its side with the basal parts in the soil. It should root within a month or two and a small plant will proliferate from the base. It can be planted out as soon as it is large and firm enough to handle.
- Hooker, J. D. 1869. Curtis's Botanical Magazine.t.5812
- Van Jaarsveld, E.J. 1994. Gasterias of South Africa. Fernwood Press, Cape Town Ernst van Jaarsveld Kirstenbosch NBG June 2004
Ernst van Jaarsveld
Kirstenbosch National Botanical Garden
Conservation information updated September 2016
Plant Type: Succulent
SA Distribution: Eastern Cape, KwaZulu-Natal
Soil type: Sandy, Loam
Flowering season: Late Summer
PH: Acid, Neutral
Flower colour: Green, Pink
Aspect: Shade, Morning Sun (Semi Shade)
Gardening skill: Average