Allostigma guangxiense

from Wikipedia, the free encyclopedia
Allostigma guangxiense
Systematics
Euasterids I
Order : Mint family (Lamiales)
Family : Gesneriaceae (Gesneriaceae)
Didymocarpoide Gesneriaceae
Genre : Allostigma
Type : Allostigma guangxiense
Scientific name of the  genus
Allostigma
WTWang
Scientific name of the  species
Allostigma guangxiense
WTWang

Allostigma guangxiense is the only kind of monotypic genus Allostigma in the family of Gesneriad (Gesneriaceae).

description

Appearance and leaf

Allostigma guangxiense growing terrestrial and evergreen perennial , herbaceous plant . It forms rhizomes . The simple, square stem is about 42 centimeters long in the herbarium specimen. The stem is covered with grayish to brownish hairs ( trichome ), with two different lengths, densely hairy.

The few leaves are arranged opposite to one another on the stem and divided into a petiole and a leaf blade. The leaves of a couple are different. The petiole is 1 to 4.5 inches long. The simple leaf blade is 6.5 to 15 centimeters long and 5 to 8 centimeters wide, oblique, egg-shaped to elliptical with a slate blade base, which is eyed to heart-shaped on the broad side and broad-wedge-shaped on the narrow side, and with a pointed to a pointed upper end. The leaf margin is finely notched. Both leaf sides are finely hairy ( indument ) and the underside of the leaf is dotted with dense yellow glands.

Inflorescence and flower

The lateral, 4.5 to 10 centimeter long inflorescence stem is finely downy or shaggy hairy. In the zymous inflorescence there are loosely arranged three to five flowers. The two opposite bracts are hairy and downy and linear with a length of 3 to 5.5 millimeters. The finely downy hairy bracts are linear. The flower stalk is finely hairy.

The hermaphrodite flowers are five-fold with a double flower envelope . The five equal approximately 1.1 centimeter long sepals are fused at their base to form an approximately 2 millimeter long calyx tube and the radially symmetrical calyx ends in five lanceolate-linear calyx lobes with a length of 8 to 9.5 millimeters, often with subtle upper ends. The five lavender-colored, inside bare, about 3.8 centimeters long petals are fused into a 2.7 centimeter long corolla tube, which is not thickened with a diameter of 8 to 10 millimeters. The zygomorphic corolla is two-lipped and the corolla lips are longer than the corolla tube. The upper lip is 4 millimeters long and ends in two corolla lobes. The lower lip is 1.1 centimeters long and ends in three somewhat dissimilar corolla lobes with rounded upper ends. There are only a pair of fertile stamens ; they do not protrude beyond the corolla tube with a length of about 1 centimeter. The stamens inserted near the center of the corolla tube are somewhat curved and somewhat wider in the center. The basifix anthers are elliptical-spherical and connected at the top. The parallel counters open longitudinally. The three bare staminodes are fused with the inside of the corolla tube; the central staminodium is about 0.5 millimeters long and the two lateral 3.5 to 4.5 millimeters. The disc is ring-shaped and the nectaries are cup-shaped. The upper, two-chamber ovary is elongated and hairy with a length of 1.2 centimeters. With allostigma the placentation is at the central angle; in this it differs from the otherwise very similar genus Pseudochirita in which the placentation is parietal. The approximately 2.8 cm long stylus is only sparsely hairy at its base. The scar has two distinctly unequal lobes, the smaller of which is about 1 millimeter long, triangular and with entire margins, and the larger, about 4 millimeters long, is narrowly inverted trapezoidal and truncated or edged.

Fruit and seeds

The downy, hairy capsule fruit standing straight on the stalk is narrow, cylindrical with a length of 4 centimeters and much longer than the calyx. When ripe, the capsule fruit opens in a way that is fissured or loculicidal with two fruit valves towards its base; the two fruit flaps stay straight and do not twist. The very fine seeds have no appendages.

Phenology

The flowering time in China is in September and the fruits also ripen in September.

Occurrence

Allostigma guangxiense is endemic to the Chinese province of Guangxi and only occurs there in the south-western part of Daxin County .

It thrives on carts in the tropical karst at altitudes of around 200 meters.

Systematics

The genus Allostigma was established in 1984 by Wen-Tsai Wang in Acta Phytotaxonomica Sinica , Volume 22, Issue 3, pages 187-188, Table 1 with the type species Allostigma guangxiense W.T.Wang . The type specimen was collected in the Chinese province of Guangxi in Daxin Xian, Taiping on karst hills in September 1976 by SY Liou and HC Nung and deposited with the collective number 414. The botanical generic name Allostigma is derived from the Greek words: αλλος allos for different, different and στιγμα stigma for scar, this refers to the two clearly different lobes of the scar. The specific epithet guangxiense refers to the origin from the province of Guangxi.

Allostigma guangxiense is the only species of the genus Allostigma that belongs to the tribe Didymocarpeae from the Didymocarpoids within the Gesneriaceae family.

swell

Individual evidence

  1. ↑ a b c d e f g h i j k l m n o p q r Anton Weber, Laurence E. Skog: The Genera of Gesneriaceae from the Faculty of Botany at the University of Vienna & Department of Systematic Biology, Botany Smithsonian Institution, 2007: Allostigma .
  2. ↑ a b c d e f g h i j k l m n o p q r s t u v w x Wencai Wang, Kai-yu Pan, Zhen-yu Li, Anna L. Weitzman, Laurence E. Skog: Gesneriaceae. in the Flora of China , Volume 18, 1998, pp. 302–308: Allostigma and Allostigma guangxiense - the same text online as the printed work.
  3. ↑ a b Allostigma guangxiense at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved November 1, 2019.

Supplementary literature

  • ZY Li, YZ Wang: Plants of Gesneriaceae in China. , Henan Science and Technology Publishing House, Zhengzhou, 2004, pp. 1-721.