Ammocharis baumii (Harms) Milne-Redh. & Schweick.
Common names: Baum’s ammocharis
Ammocharis baumii is a dwarf bulbous plant, with attractive, but fleeting, pink, sweetly-scented flowers, with an extremely long perianth tube. It is easily cultivated as a summer-flowering container subject.
Fig. 1. Ammocharis baumii flowers, close-up. (Photo: Graham Duncan)
This summer-growing bulbous plant grows from a subterranean, narrowly egg-shaped bulb, with a distinct neck, and is covered with hard, brown, outer tunics. The bulb is solitary, and has thin, perennial, fleshy roots. It has 6 to 10 linear, erect or spreading, green leaves, which usually appear in two opposite rows, or sometimes in a rosette.
Fig. 2. Ammocharis baumii narrow, linear leaves. (Photo: Graham Duncan)
The flowerheads appear in batches at staggered intervals, anytime from late spring until late summer (October to February) and each flower lasts no more than two days. The flower has a very long, narrow perianth tube 95–120 mm long, and 6 narrow, recurved tepals, which are initially white, ageing to pink, and 6 prominent, inwardly arching stamens, with long, curved anthers.
Fig. 3. Ammocharis baumii flowers, showing long perianth tubes. (Photo: Graham Duncan)
The ripe fruit is a rounded capsule, with a thin, membranous, outer layer, which disintegrates rapidly, releasing numerous fleshy, irregularly shaped, green seeds, which are covered with a thin, papery outer layer.
Fig. 4. Ammocharis baumii fruits and seeds. (Photos: Geoff Nichols)
Not yet assessed, but owing to its wide distribution, Ammocharis baumii is probably not threatened.
Distribution and habitat
Ammocharis baumii is native to the summer-rainfall, southern and south-eastern parts of Angola, northern and northeastern Namibia, and north-central Zimbabwe. It is found in seasonally inundated, deep, white sand, in floodplains, in open grassland, in small or large colonies. Occurring in areas sometimes subject to drought, the plants flower quickly in response to flooding and rainfall.
Derivation of name and historical aspects
The genus name Ammocharis is derived from the Greek ammo, meaning ‘sand’, and Charis, after a goddess of beauty in Greek mythology, referring to the occurrence of these attractive plants in sandy places. A. baumii was recorded for the first time by the German botanist, Hugo Baum, who collected it at Chirumbu, in south-eastern Angola, in October 1899. The plant was initially described in 1903, by his compatriot taxonomist, Hermann Harms, as Crinum baumii, but the English botanist, Edgar Milne-Redhead, and the German botanist, Herold Schweickerdt, later transferred it to Ammocharis in 1939, although they were uncertain whether its leaves were usually arranged in two opposite rows (biflabellate) or not. The South African botanist, I.C. Verdoorn, subsequently determined that the leaves were arranged in a rosette, and returned it to Crinum in 1973. Finally, in 2007, following a DNA study by the Zimbabwean botanist Ezekeil Kwembeya and three Norwegian botanists, C.S. Bjora, B. Stedje and I. Nordal, it was shown that the plant belongs in Ammocharis.
Ammocharis is a genus of seven species of bulbous plants, including A. angolensis, A. baumii, A. coranica, A. deserticola, A. longifolia, A. nerinoides and A. tinneana, all of which are endemic to sub-Saharan Africa. All the species are summer-growing and dormant in winter, with the exception of A. longifolia which is winter-growing and dormant in summer. Members of the genus Ammocharis are popular among specialist bulb-growers as container or rock garden plants.
Fig. 5. Ammocharis baumii flowers changing colour to deep pink. (Photo: Graham Duncan)
Ammocharis baumii is a summer-growing perennial. The bulbs are dormant during the dry winter months, and following rainfall in spring and summer, the leaves emerge first, followed by flowers within a few weeks. The flowers are sweet-scented, and the base of the very long perianth tube contains nectar, which is consumed by their night-flying moth pollinators, which are probably hawkmoths. The fruits develop rapidly, producing viable seeds within 4 to 5 weeks. The fragile capsule ruptures once the seeds are mature, and the seeds germinate immediately, close to the mother plant, or may be carried away by floodwaters to germinate elsewhere. Seedlings rapidly establish a bulb during the first summer growing season, before the dry, winter dormant period commences.
Ammocharis baumii has no magical or medicinal uses, but it is sometimes used by specialist bulb-growers as a container subject.
Fig. 6. Ammocharis baumii as a container subject. (Photo: Graham Duncan)
Growing Ammocharis baumii
The bulbs grow easily in deep, 20 cm diam. containers. Plant the bulbs close together (30 mm apart) for best effect, in a sandy, well-drained soil, such as equal parts of coarse grit and silica sand, with a layer of finely-sifted compost placed over drainage stones at the base of the container. Plant the bulbs with the top of the neck at soil level. Provide a heavy water drench in late spring (October in the southern hemisphere) followed by a weekly drench once the leaves appear, until the end of summer. Reduce watering in autumn, and keep the bulbs completely dry in winter.
The bulbs are solitary and do not form offsets, but propagation by seed is easy. Sow the seeds in pots in the same medium recommended for adult bulbs, by pressing the seeds lightly into the medium, and water well. Once the young leaves appear, water once per week until autumn, and allow seedlings to die down for the winter. Seedlings can flower for the first time in their third year.
- Duncan, G.D. 2010. Grow bulbs. Kirstenbosch Gardening Series. South African National Biodiversity Institute, Cape Town.
- Duncan, G.D. 2011. Notes on Ammocharis Herb. (Amaryllidaceae) with particular reference to Ammocharis angolensis (Baker) Milne-Redh. & Schweick. Herbertia 65: 89–107.
- Duncan, G., Jeppe, B. & Voigt, L. 2016. The Amaryllidaceae of southern Africa. Umdaus Press, Pretoria.
- Kwembeya, E.G., Bjora, C.S., Stedje, B. & Nordal, I. 2007. Phylogenetic relationships in the genus Crinum (Amaryllidaceae) with emphasis on tropical African species: evidence from trnL-F and nuclear ITS DNA sequence data. Taxon 56: 801–810.
- Milne-Redhead, E. & Schweickerdt, H.G. 1939. A new conception of the genus Ammocharis Herb. Journal of the Linnean Society (Botany) 52: 159–197.
- Snijman, D.A. & Kolberg, H. 2011. Ammocharis deserticola (Amaryllideae), a new species from Namibia and a key to species of the genus. Bothalia 41: 308–311.
- Verdoorn, I.C. 1973. The genus Crinum in southern Africa. Bothalia 11 (1&2): 27–52.
Kirstenbosch National Botanical Garden
Plant Type: Bulb
Soil type: Sandy
Flowering season: Early Summer, Late Summer
PH: Acid, Alkaline, Neutral
Flower colour: White, Pink
Aspect: Full Sun, Morning Sun (Semi Shade)
Gardening skill: Average