Monday, July 14, 2008

Aster panduratus

Genus Aster L. (Asteraceae)
A large genus but taxonomically unclear. The number of the species under Aster varies depending on different approaches, ranged from 250 to 1000. They are mainly distributed in Asia, Europe and North America; ca. 100 spp. in China including 5 in Hong Kong.

Asteraceae is the second largest family in the Division Magnoliophyta (Angiosperms), with over 20,000 described species. (The largest is Orchidaceae, with about 25,000 described species).
The "flower" of Asteraceae is actually an inflorescence (Capitulum), consisting two types of florets: ray and disc florets. The petals of ray florets attract the pollinators and provide landing platform to them.

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