Porana
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Porana is a plant genus in the family of wind plants (Convolvulaceae). Thereare only two species ina disjoint range.
description
Vegetative characteristics
Porana species are lianas that are almost hairless. They form a root system of fiber roots. The alternate leaves are arranged in a petiole and a leaf blade. The petioles are furrowed. The leaf blade is simple, entire and membranous. There is pinnate veins, the veins stand out clearly on the underside of the leaf.
Inflorescences and flowers
The inflorescences are thyrsen-shaped composed panicles , which are in the axils or rarely also terminal and are accompanied by bracts . At the junction between the peduncle and peduncle there are two scale-like prophylls. The blooming order of the flowers of an inflorescence is from the bottom to the top.
The upright, relatively small, fragrant flowers are five-fold with a double flower envelope . The sepals are free from each other and have a quinkunique (roof-top) bud cover. The outer sepals are about half as long as the crown . This is bell-shaped or broadly funnel-shaped-bell-shaped, the five corolla lobes are folded and flap-covered, but not twisted. On the outside, the thickenings along the axis of the petals (interplicae) are hairy, the agglomeration folds of the petals are transparent and hairless.
The five stamens are of unequal length, the longest two or three protrude beyond the crown. The hairless stamens are fused with the corolla tube in the lower area, they are free in the upper area. The anthers are elliptical and open lengthways before the flower opens. The pollen grains are tricolor and not studded with spines. The pistil protrudes beyond the crown, the flower base is ring-shaped. The ovary is single-chambered or incompletely divided into two chambers. It contains four basal, upright ovules . The styles are terminal, irregularly two-branched and have two kidney-shaped scars .
Fruits and seeds
As the fruit ripens, the sepals enlarge evenly or the outer three enlarge more than the inner two, they become membranous, so that the parallel veins with seven to nine longitudinal veins are visible.
The fruits are membranous nuts with a visible seam. They open irregularly or spring open late along the seam. They usually contain one (rarely two) seeds . The seed surface is scabby at first, but later becomes smooth. The hilum is located at the base of the seed and is C-shaped.
Systematics and distribution
The genus Porana was established in 1768 by Nicolaas Laurens Burman .
The genus Porana has a disjoint distribution area, one species occurs in Southeast Asia and Malaysia , the second species in Mexico.
According to Staples 2006, the genus contains only two species:
- Porana nutans (Choisy) O'Donell (Syn .: Porana velutina (M.Martens & Galeotti) Hallier f. ): It occurs only in Mexico .
- Porana volubilis Burm.f. : It occurs from Malesia to Indochina .
The type species is Porana volubilis . Within the convolvulaceae family, the genus belongs to the tribe Dichondreae . Other species that were previously assigned to the genus are now assigned to the tribe Cardiochlamyeae .
swell
- GW Staples: Revision of Asiatic Poraneae (Convolvulaceae) - Cordisepalum, Dinetus, Duperreya, Porana, Poranopsis, and Tridynamia . In: Blumea , Volume 51, December 2006, pages 403-491.
Individual evidence
- ↑ a b Rafaël Govaerts (Ed.): Porana - data sheet at World Checklist of Selected Plant Families of the Board of Trustees of the Royal Botanic Gardens, Kew. Last accessed on February 14, 2015.