Picrasma
Bitter wood ( Picrasma quassioides )
Picrasma, colloquially also bitter wood, is a genus deciduous trees of tropical and subtropical America and Asia. Well known is the kind Picrasma quassioides, referred to as the genus as bitter wood, remarkable for its autumn colors.
- 5.1 Literature
- 5.2 Notes and references
Description
The genus comprises Picrasma deciduous trees with light to dark reddish brown, bare branches, which are densely covered with longish gray Korkporen and have a distinct medulla. The buds are silky shiny, silvery brown hairy. The terminal buds are 5 millimeters long. The bark has a bitter taste.
The leaves are arranged opposite one another and are clustered at the ends of branches. They are pinnate, the base of the leaf stalks and stems of the leaves are often formed as a pulvinus. The leaves are entire or serrated. The stipules are dropped early or retained.
Flowers and Fruit
The flowers are unisexual or polygamous. They are arranged in loose, axillary panicles. The single flower opposed journal sheet is small or is dropped early. The individual flowers are four - or fünfzählig and have an indented in the lower half of pedicel. The sepals are small, free-standing or partially fused. The petals do not overlap hardly up. They are pointed, longer than the sepals and are retained in female flowers. The four or five stamens are inserted at the base of the four-to five-lobed discus. The two to five carpels are free and have one ovule. You are regressed in male flowers. The stylus is fused at the base, the scar is free.
The fruits are up to 10 centimeters long and up to 25 centimeters wide panicles. The 6 to 7 millimeters wide, ovate - spherical stone fruits are arranged in a ring. The thin, juicy fleshy mesocarp turns red to maturity.
Chemical properties
The occurrence of petroselinic acid in Picrasma and their absence in Ailanthus support the formation of an own subgroup with Picrasma and Holacantha and Castela within the Simaroubaceen, which is also supported by genetic studies.
Distribution and habitat requirements
Members of the genus can be found in tropical and subtropical Asia ( from the Himalayas to Japan, Malaysia and Fiji ) and America.
System
The Bitter wood ( Picrasma ) is a genus in the family of bitter ash plants ( Simaroubaceae ). Synonyms of the genus are Aeschrion and Picraena. The genus includes about nine species, including:
- Picrasma chinensis P.Y. Chen
- Picrasma crenata in Engl Engl & Prantl
- Picrasma excelsa ( Sw. ) Planch.
- Picrasma mexicana Brandegee
- Picrasma quassioides (D. Don ) Benn.