Daubenya

Daubenya aff. marginata

The Daubenya are a genus within the family asparagus plants ( Asparagaceae ). The eight species occur only in South Africa, seven of them only in the provinces of North Cape and Western Cape, and Pincushion Lily ( English ) are called there.

• 4.1 Notes and references

Description and Synecology

Appearance and leaves

Daubenya species grow as perennial herbaceous plants. These geophytes form underground, almost spherical onions as outlasting whose jacket ( " Tunic " ) is outside thin leathery and brownish. The thick roots are branched.

Only during the rainy season leaves are present. There are only two basal, prostrate leaves present simultaneously with the flowers. The simple, bare, shiny, leathery leaf blades are relatively broad and oblong to broadly elliptic. There is Parallelnervatur and the veins are sunk.

Inflorescences, flowers and pollination

Terminally relatively short, upright Blütenstandsschäften and so close to the basal foliage leaves are compact, schirmtraubige or rarely, by stretching of the inflorescence axis, racemose inflorescences containing many flowers. There are at the bottom of large and above small green or membranous bracts present. Bracts absent. The almost upright flower stalks are short up, especially the lower, more or less long.

From hermaphrodite, threefold and often fragrant flowers sometimes the lower more or less distinctly zygomorphic and most but radial symmetry. The six identically shaped, or more or less distinctly unequal bracts are medium grown long tubular and salverform to very. The free part of the bloom is almost upright, oblong- lanceolate. In the most extreme cases of zygomorphic flowers upper bracts are greatly enlarged and reversed - lanceolate. The colors of the bracts are white to pink or from yellow through orange to bright red. There are two circles, each with three stamens present. The Mouth of the Blütenhüllblattröhre inserted, more or less upright stamens are strong and free or fused into a more or less long Staminalröhre. Rarely the mouth of the terete Staminalröhre is closed by a thickened disc and the stylus protrudes through. The three carpels are fused to an egg-shaped or inverted - triangular, superior ovaries. The ovary chamber some ovules are present. The thin, stalk round pen is much longer than the ovary, and ends in a tiny scar.

Pollination is very different with very different morphological adaptations of flowers depending on the type. In well- scented flowers honey bees and butterflies are attracted as pollinators. For two species, the flowers do not smell. Daubenya Zeyeri attracts large amounts of nectar nectar birds ( Nectariniidae ) for pollination. Daubenya aurea is visited by beetles ( of the subfamily Hopliinae, Scarabaeidae ); their " flowers " are at the bottom zygomorphic flowers, the outer bracts enlarged ( Cantharophilie ).

Fruits, seeds and seed dispersal

The egg-shaped or inverted - triangular and three -bladed, parchment-like fruit capsules contained in each fruit trade some seeds. Usually the fruit capsules open when ripe, but rarely when the stylus is preserved as a bill they do not open until late. The nearly spherical seeds have a black, smooth or finely wrinkled, tight-fitting seed coat ( testa).

As in most species the fruits are near the ground is no wide spread. Is different with Daubenya capensis with her lengthens the inflorescence stem and flower stems to fruit maturity, expose the balloon-like fruit stand with the winged capsule fruits and sail-like bracts above the ground and the seeds are widely spread by the wind.

Chromosome numbers

The basic chromosome numbers be x = 17 or 16

Distribution and threat

The genus Daubenya occurs almost exclusively in the two South African provinces of Northern Cape and Western Cape. Only Daubenya comata also has deposits in Free State and North West. Six types are elements of the Flore capensis. Up to Daubenya comata the Daubenya species have relatively small distribution areas. Daubenya species thrive almost exclusively in winter rainfall areas.

All Daubenya species are listed in the red list of endangered species in South Africa. As " Endangered " = " high risk " applies Daubenya aurea. " Vulnerable " = "at risk" are Daubenya stylosa Daubenya zeyheri. Daubenya capensis is described as " Near Threatened " = " low risk" rated. The status of "Least Concern" = " not at risk " have Daubenya comata and Daubenya marginata. Daubenya alba and Daubenya namaquensis are rare, but not endangered.

System

The genus Daubenya in 1835 by John Lindley in Edwards 's Botanical Register, 21, pl. 1813 set up. The genus name honors the English botanist Charles Daubeny Daubenya. Type species is aubenya aurea Lindl .. Synonyms for Daubenya Lindl. are: Amphisiphon WFBarker, Androsiphon Schltr, Neobakeria .. Schltr.

The genus Daubenya was set up with only one kind and a long time they remained monotypic. In Alison M. van der Merwe & John C. Manning in Strelitzia, Volume 9, 2000, S. 713, the monotypic genera Androsiphon and Amphisiphon were incorporated into Daubenya. The last revision of the genus Daubenya was in John C. Manning & Alison M. van der Merwe: Systematics of the genus Daubenya ( Hyacinthaceae: Massonieae ) In Bothalia, Volume 32, Number 2, 2002, pp. 133-150; this species from the genus Massonia were asked to Daubenya.

The genus belongs to the subtribe Daubenya Massoniinae from the tribe Hyacintheae in the subfamily Scilloideae within the family Asparagaceae. It was formerly classified in the family Liliaceae or Hyacinthaceae.

There are about eight Daubenya species, here with occurrence and hazard:

• Daubenya alba AMvan der Merwe: This rare but not endangered species was first described in 2002. The distribution area of this habitat specialist is small. It occurs only on the Roggeveld Escarpment between Calvinia and Middelpos in the Northern Cape. It thrives in the Succulent Karoo on seasonally waterlogged, clayey soils on dolerite on low hills or at the foot of rocky dolerite outcrops.
• Daubenya aurea Lindl. ( Syn: .. .. . Massonia aurea ( Lindl. ) G.Don, Hort Brit, Massonia lutea Lindl, Daubenya fulva Lindl, Daubenya coccinea Harv ex Baker, Daubenya aurea var coccinea ( Harv. ex Baker ) Marloth ): It occurs only on the Roggeveld Escarpment between Sutherland and Middelpos in the Northern Cape. It thrives in the Fynbos and the Succulent Karoo in arid bushland, in seasonally moist places, on red Lehmebenen along the base of dolerite ridge. Due to expansion of agriculture and overgrazing the very small habitats are currently threatened. It is considered as " Endangered " = " critically endangered ", although it is still often at some sites.
• Daubenya capensis ( Schltr. ) AMvan der Merwe & JCManning ( Syn: Androsiphon capensis Schltr. ): This endemic species is only known from eight sites in the Bokkeveld Escarpment and Western Karoo in the Northern Cape. The distribution area of this habitat specialist is small. It thrives in the Fynbos and Succulent Karoo in the on saisional damp locations on clayey soils on dolerite. In the 1950s 13 % of its habitat has been wrapped in wheat fields. At the locations intensive grazing takes place, but this type is not sensitive to grazing. It is regarded as " Near Threatened " = " low risk" because the stocks are stable.
• Daubenya comata ( Burch. ex Baker ) JCManning & AMvan der Merwe ( Syn: Massonia comata Burch ex Baker, Polyxena comata ( Burch. ex Baker ) Baker, Neobakeria comata ( Burch. ex Baker ) Schltr. . ): It is the most widely Daubenya - type and occurs in the Eastern Cape, Western Cape, Free State and North West. It thrives in the Nama Karoo, grasslands and savannas in saisional water-saturated loamy or clayey soils. Your library does not take off and it is considered "Least Concern" = " not at risk ".
• Daubenya marginata ( Willd. ex Kunth ) JCManning & AMvan der Merwe ( syn.. Massonia marginata Willd ex Kunth, Polyxena marginata ( Willd. ex Kunth ) Baker, Neobakeria marginata ( Willd. ex Kunth ) Schltr, Massonia rugulosa light.. . ex Kunth, Polyxena haemanthoides Baker, Polyxena rugulosa ( Licht. ex Kunth ) Baker, Neobakeria haemanthoides ( Baker) Schltr, Neobakeria rugulosa ( Licht. ex Kunth ) Schltr ). It is relatively widespread in the Northern Cape and Western Cape on the Roggeveld Escarpment and western Karoo between Calvinia, Sutherland, Fraser castle and Loxton and has isolated populations on the Bokkeveld Escarpment and Knersvlakte. This type thrives in the Succulent Karoo on saisional wet sinks in silty or sandy loam. It is considered "Least Concern" = " not at risk " rating.
• Daubenya namaquensis ( Schltr. ) JCManning & Goldblatt ( syn.. Neobakeria namaquensis Schltr, Polyxena namaquensis ( Schltr. ) K.Krause ): It is a rare, but not endangered species of which there are only small colonies whose populations on the small areas, however, are stable. This endemic species is a habitat specialist of Namaqualand. He thrives in the Nama Karoo in deep red sand along gutters, in semi-arid plains east of Springbok in the Northern Cape and Okiep.
• Daubenya stylosa ( WHBaker ) AMvan der Merwe & JCManning ( Syn: Amphisiphon stylosus WHBaker ): This endemic species is known only from three locations in the Bokkeveld Escarpment in the Northern Cape. It thrives in the Fynbos and Succulent Karoo in to deep gullies on clayey soils on dolerite. He is described as " Vulnerable " = " at risk " rating and stocks are considered to be stable. The threat is made by farming and grazing; about 17 % of the originally very small area have already been lost.
• Daubenya zeyheri ( Kunth ) JCManning & AMvan der Merwe ( Syn: .. . Massonia zeyheri Kunth, Massonia lanceolata Zeyh ex Kunth nom illeg, Massonia burchellii Baker, Massonia pedunculata Baker, Polyxena burchellii ( Baker) Baker, Neobakeria burchellii (Baker ) Schltr ). endemic This is only one of ten locations in a very small area between Paternoster and Langebaan in the Western Cape known. It thrives in the fynbos mostly in coastal granite boulders and sometimes on adjacent sandy areas and hardpan. The populations are small, with the largest 500 and 1000 adult specimens included. Overall, there is probably only 6500 copies in nature. Through coastal development takes place a constant habitat loss. He is regarded as " Vulnerable " = "at risk" and the stocks decrease.

Swell

• John C. Manning, Peter Goldblatt & Dee Snijman: The color encyclopedia of Cape bulbs, Timber Press, Portland and Cambridge, 2002, ISBN 0-88192-547-0. Eucomis on page 154-155 (Sections Description, distribution and systematics )
• John C. Manning: South Africa's Jewels of the Desert: A Reappraisal of the genus Daubenya ( Hyacinthaceae ) In: Herbertia, Volume 56, 2001, pp. 61-66. PDF file.
• John C. Manning & Alison M. van der Merwe: Systematics of the genus Daubenya ( Hyacinthaceae: Massonieae ) In Bothalia, Volume 32, Number 2, 2002, pp. 133-150.