Centaurea macrocephala
giant knapweed
Asteraceae
Characteristics: Macrocephala = big head. Big head, indeed! Yellow flowers look like a head of messy hair on top of a brown artichoke. Upright, showy perennial- 250-300 flowers in each clump. Bees go crazy for it! Grows 1m tall
Growing conditions: Tolerant of poor, dry soil. Excellent for a garden without a lot of irrigation (but not xeriscape).
Limitations: Stands out quite a bit.