Common name: Yellow Hardhead, Bighead Knapweed, Giant Knapweed, Armenian Basketflower, Globe Centaurea. Scientific name: Centaurea macrocephala. Family: Asteraceae. Genus: Centaurea. Plant type: Perennials. Height: Height: 3 to 4 feet. Flower color: Bright yellow. Flowering time: June - July. Plant Type: Herbaceous perennial. light-green leaves,thistle-like flowers