Canellaceae
White Zimtrindenbaum ( Canella winterana )
The Canellaceae are a tropical plant family with evergreen trees.
- 4.1 Literature
- 4.2 Notes and references
- 4.3 External links
Features
Habit and stem
The Canellaceae are evergreen trees, rare shrubs. The tribe has a cork cambium. The nodes are tri - or bi- lakunär lakunär with three leaf-trace strands. An internal phloem does not exist. The secondary growth takes place normally. The xylem contains tracheids. The ends of the vascular cells are pierced diagonally and scalariform or reticulate. The sieve tube plastids belong to the P- type.
It is characterized by thick, leathery, aromatic, ganzrandigen leaves without stipules. The stomata are usually paracytisch, rare anomocytisch. The mesophyll of the leaves contains spherical cells with essential oils. Furthermore, crystal geodes can be found in the mesophyll composed of calcium oxalate. The small Blattleitbündel (minor leaf veins ) have no phloem transfer cells in Canella.
Inflorescence and flowers
The inflorescences are different. There are single flower, cymöse and razemöse inflorescences. The flowers are hermaphrodite. The perianth is divided into calyx and corolla, usually arranged cyclic, rare schraubig. The cup is in threes and persistent. There are (four) five to twelve free ( often intergrown ) petals. One other interpretation by the three sepals bracts. Then the perianth would be similar.
The six to twelve ( at Cinnamosma many ) stamens are fused together to form a tube. All stamens are fertile. The anthers are on the outside of the tube. They open with longitudinal slots. Each anther consists of two bisporangiaten counters ( tetrasporangiat ). The anther wall initially has more than one middle layer. The tapetum is glandular. The pollen is used as single grains. The pollen grains are monosulcat, the aperture can also be V-shaped or hair -shaped. The pollen is two-celled.
The gynoecium consists of two to six carpels. The ovary is upper constant. The placentation is parietal. In single seed tray there are two to many campylotrope, bitegmische, crassinucellate ovules. The ovules are horizontal to upright at the Plazente in single or double rows. The micropyle is the zig- zag. The embryo sac develops according to the Polygonum type. The stylus is a short and thick, the scar lobed two -to six- fold.
Fruits
The fruit is a berry. Each berry contains two to 100 seeds. The outer seed coat ( Exotesta ) is sclerotized. The seeds contain abundant endosperm. This is ruminiert (through the folds of tissue of the seed coat broken ) or not ruminiert. The endosperm is oily. The embryo is small, but well developed. He has two cotyledons and is slightly curved or straight.
The chromosome number is n = 11, 13, 14
Ingredients
The family makes cyanogenic glycosides. All previously studied representative of the family contain sesquiterpenes of drimane type. This group is relatively rare among angiosperms and occurs about even in the related Winteraceae, but also in Polygonum hydropiper. Polygodial that occurs among others in Warburgia stuhlmannii and W. ugandensis, has a fungicidal effect.
Dissemination
The family is native to the tropics. It occurs in South America, the West Indies and in South Florida as well as in Africa and Madagascar.
System
The family includes five to six genera with 13 to 21 species:
- Canella P. Browne, with only one kind in South Florida and the West Indies: White Zimtrindenbaum ( Canella winterana (L.) Gaertn; Syn. Canella alba Murray )
Sources and further information
The article is based primarily on the following links:
- Canellaceae on the APWebsite
- Canellaceae in L. Watson and M. J. Dallwitz (1992 onwards ), The families of flowering plants