Haworthia

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Haworthia
Haworthia glauca
Scientific classification e
Kingdom: Plantae
clade: Angiosperms
clade: Monocots
Order: Asparagales
Family: Xanthorrhoeaceae
Subfamily: Asphodeloideae
Genus: Haworthia
Duval
Species

Around 70, including:
Haworthia angustifolia
Haworthia arachnoidea
Haworthia attenuata
Haworthia coarctata
Haworthia cooperi
Haworthia cymbiformis
Haworthia emelyae
Haworthia fasciata
Haworthia glabrata
Haworthia glauca
Haworthia limifolia
Haworthia maraisii
Haworthia mirabilis
Haworthia pygmaea
Haworthia reinwardtii
Haworthia retusa
Haworthia truncata
Haworthia turgida
Haworthia venosa
Haworthia viscosa

Haworthia is a genus of flowering plants within the family Xanthorrhoeaceae, subfamily Asphodeloideae.[1]. They are small (typically 20 cm high) solitary or clump-forming and endemic to South Africa. Some species have firm, tough leaves, usually dark green in color, whereas other are soft and semi-translucent. Their flowers are small, white and very similar between species. But their leaves show wide variations even within one species.

The classification of the flowering plant subfamily Asphodeloideae is weak and concepts of the genera are not well substantiated. Haworthia is similarly a weakly contrived genus consisting of three distinct groups: sub-genera Haworthia, Hexangularis, and Robustipedunculares. Related genera are Aloe, Gasteria and Astroloba and intergeneric hybrids are known.

The genus Haworthia is named after the botanist Adrian Hardy Haworth. Bayer recognizes approximately 61 species whereas other taxonomists are very much less conservative (1999, Haworthia Revisited, Umdaus Press). The species are endemic to South Africa, Swaziland, Namibia and Maputoland. The plants are small, forming rosettes of leaves from 30mm to exceptionally 300mm in diameter. These rosettes are usually stemless but in some species stems reach up to 500mm.

Their flowers are small, white and very similar between species. There are differences in the flowers of the three sub-genera that botanists have curiously considered inconsequential although the differences between species in the same subgenus definitely are. The roots, leaves and rosettes do demonstrate some generic differences while wide variations occur even within one species. Because of their horticultural interest, the taxonomy has been dominated by amateur collectors and the literature is rife with misunderstanding of what the taxa actually are or should be.

There is widespread special collector interest but some species such as Haworthia attenuata and Haworthia cymbiformis, are fairly common house and garden plants. Haworthia species reproduce both through seed and through budding, or offsets. Certain species or clones may be more successful or rapid in offset production, and these pups are easily removed to yield new plants once a substantial root system has developed on the offshoot. Less reliably, the plants may also be propagated through leaf cuttings, and in some instances, through tissue culture.


[edit] References

[edit] External links


Personal tools
Namespaces
Variants
Actions
Navigation
Interaction
Toolbox
Print/export
Languages