Stegnosperm

Stegnosperm
Stegnosperma cubense
Systematics
Class : Bedecktsamer (Magnoliopsida) Eudicotyledons Nuclear eudicotyledons Order : Clove-like (Caryophyllales) Family : Stegnospermataceae Genre : Stegnosperm
Scientific name of the  family
Stegnospermataceae
( H.Walter ) Nakai
Scientific name of the  genus
Stegnosperm
Benth.

Stegnosperma is the only genus of the family of Stegnospermataceae in the order of caryophyllales (Caryophyllales) within the flowering plant (Magnoliopsida). The distribution areas of the only three to four species are in Central America , on the Caribbean islands and in the Sonoran Desert .

description

Deciduous leaves and infructescence of Stegnosperma cubense

Branch with leaves and section of an inflorescence with five-fold flowers in detail from Stegnosperma halimifolium

Vegetative characteristics

Stegnosperma species are woody, xerophytic plants that grow as shrubs or lianas and reach heights of 1 to 8 meters. They have overhanging branches and all three types are more or less strong climbers. The aboveground are completely bare (without trichomes ). The bark is gray to reddish brown.

The anatomy of wood distinguishes this family from all others. The abnormal secondary growth occurs through a concentric cambium. The sieve-tube plastids are of the P-type.

The alternate and spirally arranged leaves are divided into a petiole and a leaf blade. The simple leaf blade is fleshy, succulent , 2 to 5 inches long, with pinnate veins and a smooth leaf margin. There are no stipules.

Generative characteristics

They form lateral or terminal, zymöse or panicles , traubigwirkende inflorescences , which have at most a length of 10 centimeters. There are bracts and two bracts per flower.

The hermaphrodite flowers are radially symmetrical with a diameter of only 5 to 8 millimeters ; they are five-fold and have a double flower envelope (perianth). The five green, durable sepals are at most briefly fused at their base and longer than petals. The five, rarely less, greenish, reddish to white petals are weakly nailed. There are two circles with five fertile stamens each and they protrude above the flower envelope. The stamens are fused together to form a ring at their base; those of the outer circle are not, but those of the inner circle are fused with the petals. The pollen grains have three apertures and are colpat. Three to five carpels are fused to upper ovary nodes , which become simple in the course of their development. The three to five ovules are in basal, free, central placentation . The stylus , which is at most short, has the same number of short, bent back scars as carpels from which it arises.

The leathery, three- to five-fold capsule fruits have a diameter of 5 to 8 millimeters and contain one to five seeds . The small (2 to 3 millimeters), starchy seeds are surrounded by a large, fleshy, initially white, reddish aril when ripe . The black, shiny seed coat (testa) is thin and smooth. The well-differentiated embryo is curved.

ingredients

It is ellagic acid present.

Systematics and distribution

This neotropical family has occurrences from Mexico to Central America to the Caribbean islands. They thrive in subtropical to tropical areas.

The genus name Stegnosperma was first published in 1844 by George Bentham in The botany of the voyage of HMS Sulfur , 17. The genus name Stegnosperma is derived from the Greek and directly translated means "covered seed". Type species is Stegnosperma halimifolium Benth. The genus Stegnosperma was previously classified as the subfamily Stegnospermoideae in the family of the Phytolaccaceae and today forms a separate family Stegnospermataceae in the order of the Caryophyllales . The Stegnospermataceae family was listed by Takenoshin Nakai in Journal of Japanese Botany , 18, p. 108 in March 1942 .

The family Stegnospermataceae contains only one genus with only three to four species:

• Stegnosperma cubense A.Rich. : It iswidespreadnext to Cuba , on other islands of the Greater Antilles, in Central America to southern and eastern Mexico.
• Stegnosperma halimifolium Benth. : It occurs in Mexico in the northwestern part of the Sonoran Desert , in Baja Norte and Baja Sur.
• Stegnosperma sanchezii Medrano & Medina : It occurs only in the Mexican state of Puebla .
• Stegnosperma watsonii D.J. Rogers : It occurs in the Mexican states of Baja California , Sinaloa and Sonora .

swell

• The family of Stegnospermataceae in APWebsite. (Sections systematics and description)
• The Stegnospermataceae family at DELTA by L. Watson & MJ Dallwitz. (Section description)
• Jon LR Every: Neotropical Stegnospermataceae at Neotropical Flowering Plants - neotropikey by Royal Botanical Gardens Kew .
• Vernon H. Heywood , Richard K. Brummitt , Alastair Culham, Ole Seberg (Eds.): Flowering Plant Families of the World. Firefly Books, Buffalo, NY 2007, ISBN 978-1-55407-206-4 : Stegnospermataceae on p. 310.

Individual evidence

1. ↑ JW Nowike: Palynotaxonomic study of Phytolaccaceae , in Annals of the Missouri Botanical Garden , Volume 55, Issue 3, 1968, pp. 294-364.
2. ↑ Stegnospermataceae in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
3. ^ FG Medrano, R. Medina: Boletín de la Sociedad Botánica de México , Volume 46, pp. 37-41, F. 1-2, 1984 (1986).

Web links

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