Nasa (genus)

Nasa is a genus of the family of flowers nettle plants ( Loasaceae ). It contains about 100 species that are native to Central and South America, making it the most species-rich genus of the family.

Description

These are shrubs, subshrubs or herbaceous plants that are occupied with nettle hair and reach a height from 5 to 400 centimeters. The primary root goes back gradually during growth in mature plants are found only adventitious roots that grow from the trunk base resting on the floor.

The leaves are arranged opposite or alternate. The leaf blades are ovate or circular and lobed, palmate or pinnate or more times pinnate, occasionally an umbrella shape.

The inflorescences are terminal and thyrsenähnlich with dichasisch or monochasisch, before every single flower is a rekauleszentes bract.

The petals are white, yellow, orange or red, and often two colors. The outer staminodes are fused and form a shed sheet ( nectar scale ), at the back, up to three calli his winged but also at the top and can be provided on the outer side with nectar pouches. The inner staminodes are L-shaped, on their approach are occasionally excesses.

The placentas are simple, the capsule is cylindrical round to and opens the basis of three to five tabs at the top of the fruit. The seeds are ovoid, round or slightly angular. The chromosome number is 2n = 28 and 56

The seeds of the species exhibit high levels of pharmaceutically valuable fatty acids ( gamma -linolenic acid and stearidonic ).

Dissemination

The genus has its diversity center in Colombia, Peru and Ecuador, a few species are also found in Chile, Bolivia and Venezuela to Central America (southern Mexico). The majority of the species thrives in cloud forests, some species are weeds of cultivated land, but few are also in semi-deserts, coastal forests, rain forests and other areas.

System

The genus is classified in the subfamily Loasoideae, Tribe Loaseae. The genus include:

Evidence

• Maximilian Weigend: Loasaceae. In: Klaus Kubitzki (ed.): The Families and Genera of Vascular Plants. Volume 6: Flowering Plants, Dicotyledons: Celastrales, Oxalidales, Rosales, Cornales, Ericales. Springer, Berlin / Heidelberg / New York 2004, ISBN 3-540-06512-1, pp. 248, doi: 10.1007/978-3-662-07257-8 ( limited preview on Google Book Search ).
• Maximilian Weigend: Familial and generic classification, online, accessed August 1, 2008