The majority of Old World succulent monocotyledons are grouped into the Aloaceae, a medium sized family of rosulate leaf succulents including Aloe, Astroloba, Bulbine, Chortolirion, Gasteria, Haworthia and Poellnitzia. The Aloaceae are distributed across southern Africa, Arabia, Madagascar and the Mascarene Islands. A few Bulbines are found in Australia. The largest genus is Aloe with more than 400 species.
You can download higher quality images by clicking on the pictures below.
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Haworthia - Henri Duval (1809)
named for: Adrian H. Haworth (1768-1833), English botanist
The genus includes more than 70 species of small succulent plants from Southern Africa, generally with fleshy leaves formed into a rosette. Individual leaves may have pointed, blunt or rounded tips. Many species are green but others display a range of brown or reddish-brown pigments, especially in direct sunlight, and leaves may be attractively marked. The leaves of some species have transluscent "windows" on their upper surface.
There is considerable variation of form between different species, and subspecies. In their habitat they often benefit from the shade of shrubby plants or rocks, which also afford protection from predators. The iregular two-lipped flowers are generally small, white, tubular and on the end of a long flower spike which may be simple or branched. Differences in flower form are used to group individual species into sub-genera (Haworthia, Hexangulares, Robustipedunculares).
Cultivation: Many Haworthias are small plants, suitable for a small collection, and tolerate partial shade. They are often seen below the staging in glasshouses, but may not develop their full colour in such a position. Their growing season tends to be during the winter months and roots are often lost during summer months. Watering at the wrong time of year may kill the plant, so some sensitivity to the active growing cycle is required. Haworthias produce spikes of small white tubular flowers, but are generally grown for their decorative leaf markings and architectural forms. Occasional watering with systemic insecticides based on Imidacloprid will keep the plants free of mealy bugs, their main pest.
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Astroloba - Uitewaal (1947)
Greek: astros=star + lobus=lobe, referring to the flower shape
This genus contains 6 species closely related to Haworthia. Thin creeping or upright stems are packed with triangular leaves. The small white flowers are regular, unlike those of Haworthia, but clustered into similar racemes. Found in South Africa.
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Chortolirion - Berger (1908)
Greek: chortos=feeding place, referring to a grassland habitat + lirion=lily
Chortolirion, in this monotypic genus, has an underground bulb and narrow grass-like leaves which die back in winter. The flowers are very similar to Haworthia. It grows in grassland to 6000 ft in Southern Africa.
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Poellnitzia - Uitewaal (1940)
named for: Joseph Karl L. A. von Poellnitz (1896-1945), German botanist.
Poellnitzia rubriflora, in this monotypic genus, has very similar vegetation to Astroloba and therefore to Haworthia, except that the inflorescence consists of a horizontal raceme of bright red tubular flowers, held upright. The flowers fail to open properly. Found in winter rainfall areas of the Western Cape.
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The Haworthia Society was established in 1986, with the aim of fostering interest in the culture and propagation of all plants in the genus Haworthia and encouraging study of all matters relating to cultivation and taxonomy with a free interchange of knowledge between members.
The Haworthia Society publishes a Journal, Haworthiad, covering a range of topics about Astrolaba, Bulbine, Chortolirion, Haworthia and Gasteria, and stages a Show every two years. Seedlists are published or announced in the Journal as seed becomes available.
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Astroloba aspera
A drawing by Joyce Cocozza of a plant in the
collection of Robert D. Swan, Maryland, USA.
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