Dorstenia

Dorstenia gigas

The Dorstenien ( Dorstenia ) are a genus of the family of the mulberry family ( Moraceae ). The 100 to 170 species occur in the New World, from Africa to Madagascar and the Arabian peninsula to Sri Lanka, and into western India.

• 2.1 Kinds (selection)

Description

Appearance and leaves

Dorstenien species are diverse, and in many of their properties very variable. The spectrum within the genus Dorstenia ranges with small, annual, herbaceous perennials and over without rhizomes or tubers, geophytes and woody shrubs up to succulents ( stem or leaf succulents ). Its juice is usually milky white, rarely yellow or colorless. Present on most types of hair at least partly hook-shaped.

The most spiral and rosette, rarely two lines arranged leaves are diverse. The laminae can sign, hand, or füßförmig, whole, cut, be lobed or pinnate. Often the leaf margins are toothed or notched. The ever-present Stipules are similar multiform; usually they are leathery, sometimes large, leaf-like and durable or sometimes small, pfriemförmig and early falling.

Inflorescences and flowers

The inflorescences are formed from stem axis widened certificate flowers ( Pseudanthien ), called in mulberry plants " Hypanthodien ". In them many tiny flowers are summarized. The apparent flowers can give, convex, concave, round, oval, square, lobed, divided into two parts, star -, boat -, or tongue- shaped. Their color varies from green to yellowish and reddish to purple and brown. Under the inflorescence bracts are usually ( bracts ), scattered or in rows, sometimes carrying the tag. Sometimes missing the bracts and only her remaining tooth-shaped, pfriemlichen, spateligen or ribbon-like appendage recognizable.

The spherical, clavate, tapered or warty flowers are unisexual, the female flowers within sham prosperity mature first. The male flowers are either scattered among the female flowers or concentrated on the outer edge, or separated by a flower- free zone at the outer edge. They are stalked and carry from one to four (usually two to three) of free or almost free tepals and one to four ( usually two to three) stamens. The seated female blossoms have grown together Roehrig tepals and a free ovary with one or two, then usually unequal scars. The stone fruits are embedded in the enlarged inflorescence axis and scattered by a turgidity - spin mechanism at maturity.

Systematics and distribution

The entire distribution area extends from South Central and North America with the Caribbean over Africa including Madagascar and the Arabian Peninsula to western India and Sri Lanka.

Dorstenia is the second largest genus of the Mulberry family with some authors around 105 species. Charles Plumier named it in honor of the botanist and Marburg professor of medicine Theodor Dorsten ( 1492-1552 ). Linnaeus later took the name. Due to the huge variability of many species that form often different looking site forms, many taxa have been described in the past that are now regarded as synonyms. So in other authors are up to 170 species to be found.

Types (selection)

• Dorstenia alberti Carauta, M.Valente & Sucre: It is a herbaceous plant from Brazil.
• Dorstenia annua Friis & Vollesen: It is an annual, succulent plant from Sudan and Kenya.
• Dorstenia appendiculata Miq.
• Dorstenia arifolia Lam. It is a herbaceous plant from Brazil.
• Dorstenia asaroides Gardner
• Dorstenia astyanactis Ake Assi: It is a succulent plant and epiphytic plant with drooping stem axis of the Ivory Coast.
• Dorstenia bahiensis Klotzsch: It is a herbaceous plant of North and Central America.
• Dorstenia barnimiana Schweinf. It is a succulent, geophytische plant with spherical to pear shaped tuber from Africa.
• Dorstenia benguellensis Welw. It is a very variable, succulent and geophytische plant with disc-shaped tuber from Africa.
• Dorstenia belizensis
• Dorstenia benguellensis Welw.
• Dorstenia bergiana Hijman: It is a succulent plant with spherical tuber from the Democratic Republic of Congo.
• Dorstenia brasiliensis Lam. , It is a somewhat succulent, up to 20 cm tall plant from South America ( Uruguay to Venezuela).
• Dorstenia brownii
• Dorstenia bryoniaefolia Mart.
• Dorstenia buchananii Engl: It is a succulent plant with disc-shaped, spherical or birnrnförmiger tuber from SE Africa.
• Dorstenia cayapia
• Dorstenia contrajerva L.: It is a herbaceous plant of North America.
• Dorstenia crispa
• Dorstenia cuspidata A.Rich. It is a succulent plant with disk-shaped to spherical tuber from Africa and Madagascar: Dorstenia cuspidata Hochst. ex A.Rich. var cuspidata
• Dorstenia cuspidata var brinkmaniana Hijman