Alkali yellowtop

Images

Click on image to view full size

Alkali yellowtop

Alkali yellowtop

Alkali yellowtop

Morphology

Stem

Erect or ascending, branched or sometimes unbranched below inflorescence, glabrous or sometimes hairy at nodes, finely ridged or grooved.

Leaves

Opposite, simple, sessile, lanceolate, 1.2 to 2.8 inches long, 1/4 to 4/5 inch wide; surfaces glabrous; margins finely-toothed to nearly entire; tips tapering to sharp points; bases slightly expanded, wrapping around stem.

Inflorescence

Cluster of 12-40 small heads, dense, terminal, sometimes resembling flat-topped panicles; subtended bracts 2, leaf-like.

Flower

Heads cylindric, 1/5 to 1/3 inch long; bracts 5, in 2 unequal series; inner bracts 3, primary, elliptic to oblong-obovate, 1/5 to 1/4 inch long, yellowish-green, glabrous; outer bracts 2, much reduced, to 1/8 inch long, greenish, calyx-like; ray florets solitary, inconspicuous, sometimes absent; disk florets 3-8, corolla about 1/10 inch long, yellow.

Fruit

Achene, narrowly oblong-oblanceolate, to 1/8 inch long, somewhat flattened, 10-ribbed, dark gray to black, pappus absent, enclosing smalll seed.

Ecology

Habitat

Low waste places and disturbed sites.

Distribution

South 1/2 and northeast 1/4 of Kansas.