Dischidia
Dischidia nummularia
Dischidia, also called urn plant, is a plant genus in the subfamily of the milkweed family ( Asclepiadoideae ), the family of the dogbane family ( Apocynaceae ) is expected. At present, about 80 species of the genus Dischidia are known.
- 4.1 Types
- 5.1 Literature
- 5.2 Online Source
- 5.3 Notes and references
Description
Vegetative characteristics
The species of the genus Dischidia are usually herbaceous or succulent epiphytes with creeping stem axis, rarely also epilithisch growing, in this case, creeping on stones. They usually have pronounced adventitious roots. Otherwise, the roots sit at the nodes ( more nodes ). The stem axis measuring 1-4 mm in diameter and are bald, hairy rough or tomentose. The milky sap ( latex) is white.
The opposite or change-constant leaves only have short stems. The leaf blade varies within the genus. There are oblong- elliptical, oval to lanceolate leaf blades inverse, which are flat, lens-shaped and entire, or round and shield-shaped leaves before. The leaf blades are thin and not succulent, or leathery or thick succulent. A special feature are the types with pitcher or hose- shaped leaves (so-called " urn leaves " ) that fill the time with humus and in one or two adventitious roots grow into it.
Generative features
The Vielblütige inflorescence is often racemose, schraubelig or divided into partial inflorescences. The flowers open mostly asynchronously; just open synchronously. Often an inflorescence axis is more or less clearly developed, more rarely, several. The flower stalks are short or absent almost. The corolla is relatively narrow and urn- shaped, often very small ( a few millimeters ), but sometimes bell-shaped and relatively large. It is usually white, greenish - white, yellowish - white, cream-colored, slightly reddish, dark red to bluish - green. The flowers of many species of Dischidia appear closed during the anthesis, while in other species the flowers are wide open. The corona is annular or fünfzipfelig, the corona lobes alternate with the lobes crown. The corona point is usually zweizipfelig apical and bent inward. The corona can also be entirely absent. The most conical Gynostegium is sitting or stalked. The stylus head is conical and is enveloped by the Antherenfortsätzen. The elongated oval pollinia stand upright; the Caudiculae are usually broadly triangular. The slender, spindle-shaped and bare fruits are round or somewhat flattened and pointed at the end. They are available individually or in pairs. The flattened, brown seeds are oblong to oval and have a shock of white hair.
The chromosome number is ( at Dischidia bengalensis Colebr. , Dischidia hirsuta L. and Dischidia nummularia flower).
Way of life
The species of the genus Dischidia grow as epiphytes on trees and stones. However, they have quite different demands on light, temperature and humidity. This also reflects their large geographic range and their distribution in the vertical.
Many species of the genus Dischidia live in symbiosis with ants. The ants live in the tubular or pocket-shaped leaves or under the shield-shaped leaves. They carry material into the tubular leaves, then grow into one or two adventitious roots in the which there branch. The formation of tubular or urn -shaped leaves is dependent in some species but also on the nutritional status and location of the plant. Well -fertilized plants or plant form at a very favorable location, these sheets might not look. In other species with leaves that lie shield -like or napfschneckenartig on stones, collect ants including of material. Here, too, the adventitious roots grow into it. The shield-like leaves have an additional function: Under this leaves the moisture lasts a long time. They thus help the plant to survive dry periods. But other types without bags or shield-like leaves live myrmekophil. The ants collect the seeds and carry them in their tree nests. There, the seeds germinate and the seedlings grow from these nests.
The flowers of many species appear Dischidia closed during the flowering period; only in a few species the flower is fully open. About the pollination of flowers, little is known. The pollen is not loosely distributed on the stamens, concentrated as in many other plants, but in relatively compact pollinia, which are transported as a whole from one plant to another. The pollinia are firmly and fairly to be ripped off by insect legs. The flowers work on the principle of a terminal case: The insects stick to the side crown with her legs. When trying to break free, tear off the pollinia and stay on the legs stick. Rintz (1980 ) suggested that day - and night butterflies pollinate the flowers. Jones (2008 ) observed night and diurnal, ants, wasps, bees and flies as nectar secreting flowers, aufsaugten. He stresses, however, that this does not mean that they are the pollinators of flowers.
Occurrence
The Dischidia species occur in Southeast Asia ( southern China, the Philippines, Sri Lanka, Thailand, Vietnam, Laos, Indonesia, Malaysia and India ), Australia, Oceania, and New Guinea. They grow tropical to subtropical rain forests at altitudes between sea level and 2000 meters.
System
The genus Dischidia was erected in 1810 by the British botanist Robert Brown. The type species is Dischidia nummularia R.Br. Throughout the history of research, some synonyms have for Dischidia R.Br. accumulated: Collyris M.Vahl, Conchophyllum Flower, Dischidiopsis Schltr, Dolichostegia Schltr, Hoyella Ridl, Leptostemma Flower, Oistonema Schltr, Spathidolepis Schltr ... .. .
Jones distinguishes three sections:
- Ascidiophora with the urns or pocket-shaped leaves ( as well as " normal" leaves), myrmekophil (including the types Dischidia major, Dischidia vidalii and Dischidia complex)
- Conchophyllum, with shield or clam shell -shaped leaves, myrmekophil (including the types Dischidia diphylla, Dischidia cleisthantha, Dischidia imbricata, Dischidia collyris and many other types )
- Dischidia, exclusively with "normal" leaves, partly myrmekophil (other ways, for example Dischidia nummularia ), possibly also the species of the genus Dischidiopsis.
Species
Many species are known only insufficient, and their status is uncertain. Here is a ( non-exhaustive ) list of about 80 Dischidia types:
- Dischidia acuminata Costantin
- Dischidia acutifolia Maingay profile. ( with two subspecies. Dischidia acutifolia subsp acutifolia and Dischidia acutifolia subsp klossii ( Ridley ) Rintz. )
- Dischidia albida handle.
- Dischidia albiflora handle. ( = Dischidia collyris Wall. ? )
- Dischidia apoensis Elmer
- Dischidia astephana Scortechini e King & Gamble
- Dischidia australis Tsiang & P.T.Li
- Dischidia balansae Costantin
- Dischidia bengalensis Colebrooke
- Dischidia calva Pearson
- Dischidia chinensis Champ. ex Benth.
- Dischidia chinghungensis Tsiang & P.T.Li
- Dischidia cleistantha Livsh.
- Dischidia cochleata flower
- Dischidia collyris Wall.
- Dischidia cominsii Hook.
- Dischidia complex grip.
- Dischidia cornuta Livsh.
- Dischidia diphylla Elmer
- Dischidia dohtii Tran & Livsh.
- Dischidia dolichantha Bad
- Dischidia elmeri Schltr.
- Dischidia formosana Maximowincz
- Dischidia fruticulosa Ridley
- Dischidia griffithii handle. ex Hook. f
- Dischidia hirsuta ( flower) Decaisne
- Dischidia imbricata ( flower) Steudel
- Dischidia khasiana Hook.f.
- Dischidia lanceolata ( flower) Decaisne
- Dischidia lancifolia Ridley
- Dischidia latifolia ( flower) Decaisne
- Dischidia littoralis Schltr.
- Dischidia livida Elmer
- Dischidia longepedunculata Ridl.
- Dischidia major ( Vahl ) Merrill
- Dischidia melanesica Fosberg
- Dischidia merrillii Becc.
- Dischidia milnei Hemsl.
- Dischidia nummularia R. Br
- Dischidia oiantha Schltr
- Dischidia ovata Bentham
- Dischidia platyphylla Schlecther
- Dischidia punctata (Blume ) Decaisne
- Dischidia purpurea Merrill.
- Dischidia rhombifolia flower
- Dischidia rimicola Kerr
- Dischidia rosea Schl.
- Dischidia ruscifolia Decaisne ex Beccari
- Dischidia sagittata ( flower) Decaisne
- Dischidia scortechinii King & Gamble
- Dischidia singularis Craib
- Dischidia sorsoganensis Elmer
- Dischidia superba Rintz
- Dischidia tonkinensis Costantin in Lecomte
- Dischidia truncata ( flower) Decaisne
- Dischidia vadosa Rintz
- Dischidia vidalii Beccari