alpine knapweed
Centaurea nigrescens Willd


Overview


Appearance
Centaurea nigrescens is a perennial herb with erect, branched, glabrous or somewhat long-hairy stems that grows 1.3-3.2 ft. (0.4-1.0 m) tall.
Foliage
Stems are erect or ascending, openly branched distally, villous to scabrous with septate hairs and loosely tomentose. Leaves are basal and proximal cauline, petiolate, blades oblanceolate or elliptic, 2-10 in. (5-25 cm) long, margins entire or shallowly dentate to irregularly pinnately lobed; distal cauline sessile, not decurrent, blades linear to lanceolate, gradually smaller, entire or dentate.
Flowers
Flowers are radiant or discoid, in few-headed corymbiform arrays, borne on leafy-bracted peduncles. The involucres are 0.6-0.7 in. (15-18 mm), subcylindric to ovoid or campanulate, usually longer than wide, even when pressed. Flowering summer-fall (Jun-Oct).
Fruit
Fruit are gray to light brown, 0.09-0.11 in. (2.5-3 mm) long, and finely hairy. The seeds are small, 0.02-0.04 in. (0.5-1 mm) long, and darkly colored.
Ecological Threat
Centaurea nigrescens can be found in disturbed areas including along roadsides, fields, pastures, and waste areas. It is native to Europe.

Resources


Selected Images



Maps



EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

Taxonomic Rank


Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Centaurea
Subject: Centaurea nigrescens Willd

Synonyms and Other Names


Other Common Names:
Tyrol knapweed, short-fringed knapweed, vochin knapweed

Related Scientific Names:
Centaurea debeauxii ssp. thuillieri Gren. & Godr. (Synonym)
Centaurea dubia Suter ssp. vochinensis (Bernh. ex Rchb.) Hayek (Synonym)
Centaurea pratensis Thuill., nom. illeg., non Salisb. (Synonym)
Centaurea transalpina Schleich. ex DC. (Synonym)

Categories


Plants - Forbs/Herbs

References


Common Name Reference:

Scientific Name Reference: