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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 largest genus is Aloe with more than 400 species. The Aloaceae are distributed across southern Africa, Arabia, Madagascar and the Mascarene Islands. A few Bulbines are found in Australia.
Note: recent revisions of the Aloaceae (Alooideae) based on DNA analysis from which evolutionary relationships are inferred, split the genus Haworthia:
Haworthia - for soft leaved species from subgenus Haworthia
Haworthiopsis - 16 hard-leaved species from sub-genus Hexangulares
Tulista - 15 diverse species including subgenus Robustipedunculatae & Haworthia koelmaniorum plus Astroloba, Poellnitzia & Aloe aristata.
Click on the pictures below for a higher quality image.
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Astroloba Uitewaal 1947
Name: Greek astros = star + lobus = lobe, referring to the flower shape
This genus contains 6 species of succulents 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.
Right: Astroloba aspera (Haworth) Uitewaal 1947
Syn. Astroloba corrugata N.L. Meyer & Gideon F. Smith 1998.
A drawing by Joyce Cocozza of a plant in the collection of Robert D. Swan, Maryland, USA.
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Astroloba congesta (Salm-Dyck) Uitewaal 1947
Syn. Haworthia congesta
This species grows quite large but tends to sprawl as the stems elongate. The dark green succulent leaves are hard and smooth with sharp points and no tubercles.
Native to the Eastern Cape of South Africa.
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Astroloba foliosa (Haworth) Uitewaal 1947
Syn. Haworthia foliosa
The columnar rosette is formed from light green, triangular, concave leaves whose surface may be flecked with paler green, arranged in 5 ranks or in a spiral. The column grows up to a foot tall, clumping up by offsetting from its base.
Native to the Eastern Cape of South Africa.
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Chortolirion Berger 1908
Greek: chortos=feeding place, referring to a grassland habitat + lirion=lily
Chortolirion angolense in this variable 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.
Recent taxonomic revisions recognise three species originally lumped into Chortolirion angolense and transfer the genus Chortolirion into Aloe.
New names are:
Chortolirion angolense --> Aloe subspicata
Chortolirion latifolium --> Aloe jeppeae
Chortolirion tenuifolium --> Aloe barendii
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 Haworthia Henri Duval 1809
Named for: Adrian H. Haworth (1768-1833), English botanist
The genus Haworthia 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. The species currently accepted incorporate many formerly separate species. In their habitat these succulent plants often benefit from the shade of shrubby plants or rocks, which also afford protection from predators. The irregular 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 compact plants, suitable for a small collection of succulents, and tolerating 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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Haworthia arachnoidea Duval 1809
This variable plant is distributed across the Western & Eastern South African Cape.
Haworthia arachnoidea var. pearsonii Halda 1997 Syn. H. pearsonii Wright 1907
Low rosettes are formed from many succulent light-green leaves with bristly margins and translucent stripes on their tips.
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Haworthia bolusii Baker 1880 2 varieties currently accepted:
Left: Haworthia bolusii var. blackbeardiana Bayer 1982
Rosettes up to 6 inches in diameter are formed from many translucent green succulent leaves, fringed with white spines. Native to the Eastern Cape.
Haworthia bolusii var. bolusii Scott 1985
generally has a smaller rosette of incurved leaves that form a tight ball if the plant is grown reasonably hard.
Haworthia bolusii var. odetteae has become Haworthia odetteae.
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Haworthia coarctata Haworth 1824
This variable species has at least 4 varieties which incorporate numerous older synonyms. The succulent leaves are packed around the stem to make a solid column. Individual leaves from different plants may be almost smooth or covered with white tuberculate spots and vary somewhat in length and degree of curvature. In full sun the leaves colour up red. Given sufficient room, the plant offsets at the base and tends to sprawl, but with a little support can make a handsome columnar pot plant. There is a tendency for older leaves to dry up at the base of the stem. It can be a challenge to produce a perfect plant without any dead leaves in the middle of a column.
Native to the Eastern Cape of South Africa.
Haworthia coarctata fa. greenii Bayer 1999
Syn. H. greenii Baker 1880
A variety of H. coarctata without white tubercles on the leaves, making a similar columnar plant.
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Haworthia cooperi var. pilifera cv. milky cloud Baker 1870
Named for: Cooper who introduced the species to cultivation in 1860.
The low-growing rosettes are formed from dense clusters of cylindrical green succulent leaves with small soft marginal teeth and terminal bristles. The rosette slowly offsets to form clumps. In this variegated form of garden origin, the pale fleshy foliage is patterned with whitish-grey variegation and marginal teeth are greatly reduced.
The species is native to the Eastern Cape of South Africa. Usually grows withdrawn into the ground in its habitat, with just the transparent windows in the leaf tips allowing light to penetrate the plant. There are numerous synonyms and varieties including several rather similar named variegated cultivars.
From a display by Ottershaw Cacti at the 2019 Chelsea Flower Show.
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Haworthia cuspidata Haworth 1819
Probably not a true species, but a horticultural hybrid between H. cymbiformis and H. retusa.
An individual rosette can make a handsome succulent plant but tends to clump up freely into a mass of smaller rosettes.
Quite common in cultivation.
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Haworthia cymbiformis var. cymbiformis Bayer 1982
Syn. H. planifolia Haworth 1825
The rosettes are formed from obovate green succulent leaves, unmarked and without windows but colouring up in full sun. There are numerous synonyms and varieties including a variegated cultivar.
Native to the Eastern Cape of South Africa.
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Haworthia herbacea Stearn 1938
Four varieties have been described. The small rosettes, up to 3 inches in diameter, are composed of many triangular succulent leaves fringed with white spines. The rosettes clump up slowly by offsetting at the base, but this plant will never take much space in a collection.
Native to the Western Cape and Karoo of South Africa.
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Haworthia x kewensis von Poellnitz 1940
'Kewensis' indicates Royal Botanic Gardens, Kew as the origin of the plant.
Described from a specimen sent from Kew to von Poellnitz as Haworthia peacockii but of unknown provenance.
Probably of hybrid origin but nevertheless makes a fine specimen.
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Haworthia longiana von Poellnitz 1937
Named for: F.R. Long.
Haworthia longiana has stemless rosettes formed with hard, rigid curved leaves up to 12 in long x 1 in wide. The surfaces of the succulent leaves have minute indistinct tubercles or roughening. A form with white tubercles has been described as H. longiana var. albinota GG Smith 1948. Mature rosettes offset at their base to form large clumps.
Native to a small area of the Eastern South African Cape. Very slow growing.
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Haworthia mantellii Uitewaal 1947
Not a real species but probably a hybrid between H. truncata x H. cuspidata. The leaf tips have windows reminiscent of those of H. truncata.
A handsome succulent plant worthy of cultivation. Several slightly different H. truncata hybrids are in circulation.
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Haworthia marumiana Uitewaal 1940
The pointed bright green succulent leaves have marginal spines and a transluscent quality with linear pale green reticulation, especially near their ends.
Distributed across the Western to Eastern Cape of South Africa.
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Haworthia marumiana var. batesiana (Uitewaal) M.B.Bayer 1999
Syn. Haworthia batesiana Uitewaal 1948
Named for: George Latimer Bates, American ornithologist and botanist.
This species has miniature 2 in rosettes with translucent bright green leaves marked with a net of deeper green. These succulent leaves have smooth margins and a terminal white spine. Rosettes offset freely to form dense clumps.
Native to the Western & Eastern South African Cape.
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Haworthia mucronata Haworth 1819
Numerous synonmys are lumped together into five varieties.
Haworthia mucronata var. altinlinea Halda 1997
Syn. Haworthia altilinea Haworth 1824
The light-green succulent leaves have transluscent windows near their tips. The rosettes clump up freely to make a large mass.
Native to the Western Cape and Little Karoo of South Africa.
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Haworthia odetteae Breuer 2003
forms a tight ball of incurved leaves fringed with soft spines and with a long terminal spine.
Native to the Easten Cape Province.
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Haworthia parksiana von Poellnitz 1936
Name: from catalogue number 'Parks 636/32' referring to Port Elizabeth Parks, not a person.
A very small Haworthia with tight, stemless rosettes of hard dark-green furnished with small tubercles.
Native to a small region of the Western Cape between Mossel Bay and Great Brak River, normally found growing in leaf litter under bushes. Very slow growing and dislikes excess water. Will eventually offset to form a mound.
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Haworthia pumilla Duval 1809 Syn. H. Margaretifera
pumila = small, dwarf, referring to the original description as Aloe pumila.
The incurved triangular leaves are sparsely marked with large white-ish tubercles. One branch of a multi-branched inflorescence is shown.
This species is currently lumped with H. herbacea but is a much bigger succulent plant and one of the larger Haworthia species. Native to the Western Cape of South Africa. Makes a handsome pot plant, although the tips of the leaves have a habit of drying out.
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Haworthia pygmaea von Poellnitz 1929
The rosettes are formed from thick, triangular greyish succulent leaves with some longitudinal white stripes or spots.
Native to the Western Cape of South Africa.
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Haworthia rigida Haworth 1821
Despite a long history of various synonyms starting with Aloe cylindrica var rigida Lamark 1783 this is
probably not a valid species. Possibly a hybrid of garden origin.
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Haworthia resendeana von Poellnitz 1938
Possibly of hybrid origin.
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Haworthia retusa Duval 1809 Syn. Haworthia mirabilis ssp. mundula
This Haworthia is usually a solitary, tight rosette of succulent, deltoid leaves whose windowed leaf tips are marked with linear light green or light brownish stripes. This species offsets and freely proliferating plants are known, especially among cultivated forms.
Native to the Western Cape of South Africa near Riversdale. Needs full sun to stay compact.
Lower left: Haworthia retusa var. variegata
A somewhat paler selected form.
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Haworthia truncata var. truncata Bayer 1982
Syn. Haworthia truncata f. tenuis von Poellnitz 1938
Left: A small plant with fleshy, dark-green leaves arranged in a row either side of the growing point (distichous). The flattened, translucent ends of these succulent leaves have a cut off appearance, hence the epithet. The leaf surfaces have minute tubercles. The fleshy roots are liable to rot, spreading to the rest of the plant, if the substrate is excessively wet.
Native to Cape Province of South Africa where it would grow with just the tips of the windowed leaves visible at the surface of the ground, allowing the intense sunlight to penetrate into the body of the plant. This plant is usually cultivated raised up above the substrate. Needs a lot of light and a dry Winter if the leaves are to remain compact. Prone to mealy bug getting in between the leaves.
Left: As the plant gets larger, offsets are produced whose main axis is often orientated differently to the original plant's row of leaves.
From a display by Craig House Cacti at the 2015 Chelsea Flower Show.
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Haworthia venosa ssp. tessellata Bayer 1982
Syn. H. tessellata Haworth 1824
This is a classic Haworthia with windowed and geometrically-patterned triangular brownish-green succulent leaves forming a small rosette, spreading by offsetting and via stolons. An attractive, easy plant for a pan, often grown under the older synonym.
Native to South Namibia and Northern RSA.
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Haworthia viscosa Haworth 1812
Green triangular succulent leaves are densely packed in (usually) three rows to form upright columns. The plants clump up by offsetting at the base.
Distributed across the Eastern and Western Cape and Little Karoo.
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Poellnitzia Uitewaal 1940
named for: Joseph Karl L. A. von Poellnitz (1896-1945), German botanist.
Poellnitzia rubriflora in this monotypic succulent 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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Literature
Haworthia and Astroloba: A Collector's Guide by John Pilbeam (1983)
Publisher: B.T. Batsford Ltd., London. United Kingdom. ISBN: 0-7134-0534-1
- out of print classic but often available second-hand.
Illustrated Handbook of Succulent Plants: Monocotyledons Edited by Urs Eggli (2001)
Publisher: Springer-Verlag New York. ISBN: 3540416927
Volume relevant to Haworthia from a series of comprehensive taxonomic treatments of succulent plants.
The Haworthia Society promotes interest in Haworthias, Aloes, Bulbines, Gasterias & other related South African succulents.
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