Scientific Family
Asteraceae
Synonyms
Centaurea salmantica, Microlonchus salmanticus
Other common names
knapweed of Salamanca
basketflower
Plant type
Forbs and Subshrubs
Origin
Introduced
Lifecycle
Annual or perennial
Height
To about 2-1/2 feet
Riparian
No
Erect branched plant, stems smooth above, hairy below. Oblong lower leaves are lobed and much larger than the upper stem leaves which are very narrow and sparser towards the top. Purple (rarely white) thistle-like flower heads grow singly at stem tips.
Perennial may be annual; cobwebby-hairs lower part of stems; lower leaves lobed and much larger than upper, upper narrow to lance-like; flower heads solitary, purplish, rarely white, long stemmed, bracts form rounded base and in several layers.
Habitat
Found in arid, barren, ditches and dry rocky areas along roadsides. Reported in our area only from Jerome in Yavapai County at about 5500 feet.
Plant Community
Disturbed Areas
Low elevation
0
High elevation
5500
Flower Characteristics
Flower head is 1/4 to 3/4 inch wide and consists only of many disc (tube-like) flowers. The flower head sits above a basket-like cluster of overlapping leaf-like bracts that grow in a series of layers, each bract ending in a short, sharp spine.
Flower color
Purple, white (rarely)
Flower shape
Daisy or dandelion-like
Tubular
No
First bloom month
May
Last bloom month
June
Flower clusters
None
Leaf and Stem Characteristics
Basal and lower stem leaves have a leaf stalk, are narrowly oblong and grow to about 10 inches long and 2-1/2 inches wide. Upper stem leaves are 3/4 to 1 inch long, toothed, have no leaf stalk, and grow smaller and more sparse towards the stem top.
Leaf type
Simple
Leaf color
Green
Leaf shape
Pinnatifid
Leaf margin
Lobed
Leaves clasp
No
Leaf hairs
Stems
Spines
No
Fruit and Seed Characteristics
The fruit is dry, oblong, dark brown, 1/8 to 1/4 inch long with a shiny surface that is wrinkled diagonally. On its top is a crown-like tuft of brownish-white or reddish bristles. The fruit does not split open when ripe to release the seed.
Fruit type
Achene
Fruit color
Dark brown
Each fruit produces 1 seed which is attached to a small clump of cottony fluff that is below the bristly tuft at the top of each fruit.