Brachyscome
Brachyscome is a genus of flowering plants in the aster family, Asteraceae. Most are endemic to Australia, and a few occur in New Zealand and New Guinea.[1]
The genus name is spelled Brachycome by some authors. Henri Cassini published the name Brachyscome in 1816, forming it from the classical Greek brachys ("short") and kome ("hair"), a reference to the very short pappus bristles. Because the combining form of brachys in Greek compound words is brachy-, Cassini later corrected the spelling to Brachycome. Australian taxonomists still debate whether Cassini's corrected spelling is admissible under the rules of botanical nomenclature. A proposal to conserve Brachycome was rejected in 1993 by the Committee for Spermatophyta.[2]
These are annual and perennial herbs and small shrubs. Species have a basal rosette of leaves and/or leaves alternately arranged on the stem. The blades are entire or divided. The flower heads are solitary or borne in smallcorymbs. The head has a row of ray florets in shades of white, blue, pink, or mauve, and yellow disc florets.[1]
The genus is distinguished from other genera in tribe Astereae mainly by the structure of the fruit. These achenes or cypselas are roughly club-shaped but usually incurved and flattened. They often have a membranous rim or wing around the edge that is sometimes wavy or fringed. The pappus is less than one millimeter long in most species.[3]
Brachyscome species are found in a wide range of habitats. They occupy rainy coastal and mountainous regions as well as dry central Australia.[4]
One of the annual plains species, Brachyscome dichromosomatica, is remarkable for its low chromosome count. In this species n=2, though some plants have 1, 2 or 3 additional large B chromosomes.[5] The genus has an unusually large range of chromosome counts, from n=2 to n=18.[4]
Some Brachyscome are popular as easily cultivated ornamental plants for flower gardens, and many cultivars are bred for their form, foliage, and flowers.[6]
Contents
[hide]- 1Species
- 2References
- 3External links
- 4Further reading
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