Saintpaulia

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Saintpaulia
African violets (Saintpaulia ionantha hybrid)

African violets ( Saintpaulia ionantha hybrid)

Systematics
Nuclear eudicotyledons
Asterids
Euasterids I
Order : Mint family (Lamiales)
Family : Gesneriaceae (Gesneriaceae)
Genre : Saintpaulia
Scientific name
Saintpaulia
H. Wendl.

The Saintpaulia is one of the smaller plant genus in the family of Gesneriad (Gesneriaceae). The approximately eleven species are native to the rainforests of the East African countries Tanzania and Kenya . Numerous cultivars known as African violets are popular as houseplants .

description

Hairy underside of a flower of the African violet ( Saintpaulia-ionantha -hybride) with the five almost free sepals.
Slightly zygomorphic flower of the African violet ( Saintpaulia ionantha hybrid) with the style pointing to the side.
Pollen from Saintpaulia spec.

Vegetative characteristics

In Saintpaulia types, and their species concerns perennial herbaceous plant of rosettigem (e.g., Saintpaulia ionantha , Saintpaulia rupicola ) or crawling (e.g., Saintpaulia inconspicua , Saintpaulia goetzeana , Saintpaulia ionantha subsp. Grotei , Saintpaulia ionantha subsp. Occidentalis ) growth. The above-ground parts of the plant are hairy. The short, thick or creeping stems have clear internodes and can form roots at the nodes .

The opposite or alternate arranged leaves are divided into petioles and leaf blades. The more or less fleshy leaf blades are rounded to elliptical and furry hairy.

Generative characteristics

One to several flowers stand axially on inflorescence shafts in zymous inflorescences . The bracts are small and elongated. There is a more or less long flower stalk.

The hermaphrodite, fivefold, easy zygomorphen flowers have a double perianth (perianth). The five ruler or lanceolate sepals are only fused at their base. The five petals are only very briefly fused with tubes. The crown is two-lipped with a two-lobed upper lip and a three-lobed lower lip. The extended corolla lobes have a bald top, a hairy underside and ciliate edges. The color spectrum of the petals ranges from red to pink, purple and violet to blue or white, depending on the type and variety. In wild forms only two stamens are fertile. The compact, somewhat flattened and twisted stamens are inserted in the corolla tube. The robust, large anthers are kidney-shaped and bright yellow. There are two to three staminodes present. In cultivated forms, more than all five stamens can be fertile. The short ovary is conical and densely hairy; it goes abruptly into the stylus . The stiff stylus located to the left or right of the center of the crown ends in a small, cephalic or slightly bilobed scar.

The capsule fruits are ovate to linear-cylindrical. The seeds are warty.

The chromosome numbers are 2n = 28 and in the case of cultivated forms also 30 or 60.

Occurrence

The eleven Saintpaulia species occur in rainforests in East Africa in northern Tanzania and southeastern Kenya , with the main distribution area being in the Usambara and Uluguru mountains in northeastern Tanzania.

The locations are mostly moist and shady and, depending on the species, are in the lowlands, in the middle or in the high mountains. Most of the time the plants grow on damp rocks ( lithophytes ) in the shade of trees and along rivers . Because of the extensive destruction of their habitats, all species are threatened or endangered.

Systematics

Collection of Saintpaulia spec. Wild forms in the Botanical Garden in Kaisaniemi, Helsinki

The botanist Hermann Wendland presented the genus Saintpaulia in 1893 in Gartenflora , Volume 42, 321, Plate 1391 with the type species Saintpaulia ionantha H. Wendl. on. He named it after the discoverer of the first species, the German colonial official in East Africa Adalbert Emil Walter Le Tanneux von Saint Paul-Illaire (1860–1940) and his father, Ulrich Maximilian Le Tanneux von Saint-Paul-Illaire (1833–1902), a German naval officer and politician. The first plant specimens were discovered in 1892 in the Usambara Mountains in what is now Tanzania.

The genus Saintpaulia belongs to the tribe Didymocarpeae within the "Didymocarpoiden" Gesneriaceae .

In the revision of Saintpaulia by Burtt (1958) he listed 19 species. After that, a few species were newly described, so that the number of species rose to around 22. A combination of molecular, morphological and ecological studies resulted in a reduction in the number of species. Darbyshire (2006) only accepted six, Smith et al. (1998) nine species, whereby many of the traditional species are now considered subspecies of Saintpaulia ionantha in both publications . Elspeth M. Haston described two new species in 2009, resulting in a number of eleven species valid since 2009.

Rock-dwelling African violet ( Saintpaulia rupicola ), a wild form in the Berlin Botanical Garden

The eleven valid Saintpaulia species are:

use

The hybrids of several species, called African violets ( Saintpaulia ionantha hybrid), are among the most popular flowering houseplants worldwide . A great number of varieties with simple, double or fringed flowers in many shades were bred.

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Individual evidence

  1. ↑ Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]
  2. ^ BL Burtt: Studies in the Gesneriaceae of the Old World XV. The genus Saintpaulia. , In: Notes Roy. Bot. Gard. Edinburgh , Volume 22, 1958, pp. 547-568.
  3. ^ I. Darbyshire: Gesneriaceae , In: HJ Beentje, SA Ghazanfar (editor): Flora of Tropical East Africa , Royal Botanic Gardens, Kew, 2006.
  4. ↑ Smith et al. in Edinburgh Journal of Botany , Volume 55, 1998, pp. 1-11.
  5. ↑ Elspeth M. Haston in Curtis's Botanical Magazine , Volume 26, Issue 3, 2009, pp. 273-280, plates 656 & 657.
  6. ^ Elspeth M. Haston: 656. SAINTPAULIA ULUGURENSIS. In: Curtis's Botanical Magazine , Volume 26, Issue 3, 2009, p. 273, doi : 10.1111 / j.1467-8748.2009.01660_2.x .
  7. ^ Elspeth M. Haston: 657. SAINTPAULIA WATKINSII. In: Curtis's Botanical Magazine , Volume 26, Issue 3, 2009, p. 277, doi : 10.1111 / j.1467-8748.2009.01661.x .

Web links

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