Haworthia

Haworthia
Haworthia fasciata with the "pearl warts" typical of many species.
Systematics
Class : Bedecktsamer (Magnoliopsida) Monocots Order : Asparagales (Asparagales) Family : Grass trees (Xanthorrhoeaceae) Subfamily : Affodilla family (Asphodeloideae) Genre : Haworthia
Scientific name
Haworthia
Duval

Haworthia is a genus of plants from the subfamily of the Affodill family (Asphodeloideae). The botanical name of the genus honors the botanist and zoologist Adrian Hardy Haworth . Most of the species arenativeto South Africa.

description

Vegetative characteristics

The species of the genus Haworthia are small perennial succulent plants. Some species sprout through the formation of stolons , most branching out from the base, thus forming dense groups. Few species grow individually. Their roots are fibrous to succulent and sometimes spindle-shaped.

The densely usually rosettes on the stem axis arranged leaves , only Haworthia truncata they are two lines , are sitting or are on short stems. The flat to spherical or elongated rosettes reach a diameter of 2 to 15 centimeters. The leaves are erect, spread out or bent back, sometimes severely receded. Your leaf blade triangular-lanceolate to linear and mostly firm. It often dries up from the tip and then becomes paper-like. The very pale green, blue-green to dark (blackish) green epidermis is often warty, variously patterned, glabrous and only rarely tomentose. Often there are translucent windows and reticulated veins. The upper side of the leaf is flat or runny to convex, the underside convex and often keeled towards the tip. The leaf margins are entire, serrated, ciliate, covered with bristle-like thorns or warty. The sometimes blunt or truncated tip of the leaf is usually pointed or pointed and sometimes has a pointed tip.

Inflorescences and flowers

Section of an inflorescence of Haworthia cymbiformis .

The upright, simple or branched, firm to wiry inflorescence appears from the center of the leaf rosette and bears 1 to 5 panicles with small bracts. The peduncle is brownish green and often powdery. The flowers are small, zygomorphic , double-lipped and about 15 millimeters long. There are 5 to 50 flowers per inflorescence. The flower tube is curved or straight and slightly swollen towards the base. The 6 white to pink tepals often have a green or brownish central stripe. Their tips are spread out or bent back, in the middle they are green, brownish or occasionally yellow in color. The 6 stamens do not protrude from the flower tube. The elongated ovoid to elongated ovary is dreifächrig and sechsrinnig, the stylus priemlich and the scar apical, tiny trilobal or round.

Fruits and seeds

The fruits are upright, elongated ovate, woody capsule fruits that tear open lengthways. They contain black to gray, irregularly edged or almost flat seeds .

genetics

The base chromosome number of the genus is . As with the genera Aloe , Gasteria and Poellnitzia, the chromosome set consists of four large and three small chromosomes. ${\displaystyle x=7}$

distribution

The genus Haworthia is distributed in southern Namibia and in South Africa between the 25th and 34th degrees of southern latitude and the 16th and 32nd degree of longitude. The area with the greatest biodiversity is located in the South African provinces of Eastern Cape and Western Cape in the Succulent Karoo ( succulent ) and the Nama Karoo . The plants usually grow in rocky places in the shade of grasses or bushes.

Systematics

External system

Haworthia retusa on a drawing from 1701

Haworthia belongs within the subfamily of the Affodilla plants to the monophyletic group of the Alooideae (until 2009 a subfamily of the Asphodelaceae). Based on selected morphological features, the following cladogram was derived in 1991 on the possible phylogenetic relationship of the genus Haworthia :

Alooideae	Aloe (including Lomatophyllum )      Poellnitzia      Gasteria      Astroloba      Haworthia      Chortolirion

Internal system

The first description of the genus Haworthia was made in 1809 by Henri Auguste Duval . It is divided into three sub-genera based on flower characteristics and includes the following species:

To this extent, however, the genus is not monophyletic.

× Gasterhaworthia 'Royal Highness'

Hybrids

Several hybrids within the genus and genus hybrids with closely related genera are known; z. B .: Haworthia × mantelii Uitewaal is a garden hybrid of Haworthia truncata and Haworthia cuspidata , described in 1947 , whose second parent is insufficiently secured. Furthermore, there are hybrids with the genus Aloe (× Alworthia ) Astroloba (× Astroworthia ), with x Astroworthia bicarinata (Haw.) GDRowley and Gasteria (× Gasterhaworthia ) and the triple hybrids × Bayerara D.M.Cumming (= Aloe × Haworthia × Gasteria ) × Cummingara G.D.Rowley (= Gasteria × Haworthia × Poellnitzia ) and × Maysara D.M.Cumming (= Astroloba × Gasteria × Haworthia ).

use

Haworthia limifolia has good antibacterial properties. The species istraded in Durban markets. A brew made from the leaves is used by some South African tribes, for example the Zulu , against stomach problems.

proof

literature

• Ingo Breuer: An overview of the genus Haworthia . In: Detlev Metzing, Joachim Thiede (ed.): Schumannia . Volume 2, pp. 3-74, Isensee, Oldenburg 1998.
• Urs Eggli (ed.): Succulent lexicon. Monocotyledons . Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3662-7 , pp. 207-231 .
• OA Fawole, JF Finnie, J. Van Staden: Antimicrobial activity and mutagenic effects of twelve traditional medicinal plants used to treat ailments related to the gastro-intestinal tract in South Africa . In: South African Journal of Botany . Volume 75, Number 2, 2009, pp. 356-362 ( doi: 10.1016 / j.sajb.2008.11.002 ).
• Gideon F. Smith, Ben-Erik Van Wyk: Generic Relationships in the Alooideae (Asphodelaceae) . In: Taxon . Volume 40, Number 4, 1991, pp. 557-581 ( JSTOR 1222765 ).
• Jens Treutlein, Gideon F. Smith, Ben-Erik Van Wyk, Michael Wink: Phylogenetic Relationships in Asphodelaceae (Subfamily Alooideae) Inferred from Chloroplast DNA Sequences (rbcL, matK) and from Genomic Fingerprinting (ISSR) . In: Taxon . Volume 52, Number 2, 2003, pp. 193-207 ( JSTOR 3647389 ).
• Jens Treutlein, Gideon F. Smith, Ben-Erik Van Wyk, M. Wink: Evidence for the Polyphyly of Haworthia (Asphodelaceae Subfamily Alooideae; Asparagales) Inferred from Nucleotide Sequences of rbcL, matK, ITS1 and Genomic Fingerprinting with ISSR-PCR . In: Plant Biology . Volume 5, Number 5, 2003, pp. 513-521 ( doi: 10.1055 / s-2003-44793 ).
• Canio Giuseppe Vosa: On chromosome uniformity, bimodality and evolution in the tribe Aloineae (Asphodelaceae) . In: Caryologia . Volume 58, number 1, 2005, pp. 83-85 ( PDF ).

Individual evidence

1. ↑ ^{a b c d} Urs Eggli (Hrsg.): Sukkulenten-Lexikon. Monocotyledons . P. 207.
2. ↑ Canio Giuseppe Vosa: On chromosome uniformity, bimodality and evolution in the tribe Aloineae (Asphodelaceae) . P. 84.
3. ↑ Ingo Breuer: The genus Haworthia at a glance . Pp. 3-4.
4. ^ Gideon F. Smith, Ben-Erik Van Wyk: Generic Relationships in the Alooideae (Asphodelaceae) . P. 570.
5. ^ Henri-Auguste Duval: Plantae Succulentae in Horto Alenconio . Gabon et Socis, Paris 1809
6. ↑ Urs Eggli (Ed.): Succulents Lexicon. Monocotyledons . Pp. 207-231.
7. ↑ Jens Treutlein et al .: Evidence for the Polyphyly of Haworthia (Asphodelaceae Subfamily Alooideae; Asparagales) Inferred from Nucleotide Sequences of rbcL, matK, ITS1 and Genomic Fingerprinting with ISSR-PCR . P. 520.
8. ↑ Urs Eggli (Ed.): Succulents Lexicon. Monocotyledons . P. 220.
9. ↑ Urs Eggli (Ed.): Succulents Lexicon. Monocotyledons . P. 193.
10. ↑ Urs Eggli (Ed.): Succulents Lexicon. Monocotyledons . P. 194.
11. ↑ Urs Eggli (Ed.): Succulents Lexicon. Monocotyledons . P. 199.
12. ↑ OA Fawole et al .: Antimicrobial activity and mutagenic effects of twelve traditional medicinal plants used to treat ailments related to the gastro-intestinal tract in South Africa . P. 357.

Web links

Commons : Haworthia  - collection of images, videos and audio files

• M. Bruce Bayer: Haworthia Updates : Thoughts and observations on the genus Haworthia (English)
• Ingo Breuer: Culture information for Haworthia (German)
• Haworthia plant society. (English)