SUNFLOWER FAMILY 543 
4. Centaurea diffiisa Lam. Tumble Knapweed. Fig. 5942. 
Centaurea diffusa Lam. Encycl. 1: 675. 1783. 
lants biennial with an ny ih taproot, asi Sie or pale green, pubescent or thinly floccose- 
stenoses becoming glabrate, scabrous; stems erect, (1 or) dm. tall, angled but not winged, 
ranched near or abov he branc ne poeta and intr nese Basal leaves rosulate, 
i i d wide i 
ster] : sn 
or bla ckis h “tetany striate with several conspicuous or faint, pale or ivory lines; ee none or 
on the inner achenes represented by white paleaceous scales less than 1 mm . lon 
Fields, roadsides, and waste ground, locally common; Washington and northern fea east of the Cascade 
Mountains; Tdaho and southern British sey occasional in central and eastern United States. Native in 
southeastern ican and western Asia. June—Sep 
\ WE gs 
Wi 
tre 
A 
5940. Centaurea ibe: 
5941. Centaurea ak 
. Centaurea diffusa 
5943. Centaurea maculosa 
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