Beneficial noxious weeds

[Chris J. Durden]

  Yes. I have recorded some fantastic, rich butterfly days in lower East
Rosebud Canyon, Carbon Co., Montana, in late summer. The primary attractant
was the "dreaded" spotted knapweed - a really beautiful flower.

Mabberley, 1987 (1990) "The plant-book" Cambridge - ISBN 0 521 34060 8. -
reports c.450 species of *Centaurea* including knapweeds, star-thistle,
corn-flower, mentions *C. nigra* of North America as diuretic.

Diggs, Lipscomb & O'Kennon, 1999 "Shimmers & Mahler's Illustrated Flora of
North Central Texas" BRIT (Fort Worth) - sida at brit.org - report c.500
species of *Centaurea* with 4 in NC TX -
*C. americana* - BASKET FLOWER/AMERICAN KNAPWEED, native and cultivated.
*C. cyanus* - BACHELOR-BUTTON/CORNFLOWER, exotic escapee and cultivated.
*C. melitensis* - STAR-THISTLE, exotic escapee since 1934.
*C. solstitialis* - YELLOW STAR-THISTLE, exotic escapee since 1993, cases
brain lesions and "chewing disease", a nervous disorder in horses.
  They also mention *C. maculosa* - SPOTTED KNAPWEED, exotic escapee on the
northern plains. This species is suspected of causing tumors on hands of
agricultural worker, probably carcinogenic.
............Chris Durden


At 06:09  21/01/00 -0400, you wrote:
>To the list of beneficial noxious weeds add the Knapweeds (Centaurea). 
>Among "wildflowers", they rank quite high in attracting a diversity of 
>butterflies and here in c New Jersey they flower well into October.  IN 
>some Western States some species are on the noxious list.  They spread 
>quite readily, but are also readily controlled by mowing.
>	
>M. Gochfeld
>
>