Didelta spinosa bud

An emerging Didelta spinosa flowerhead grows solitary and stalkless at a stem-tip. Two rows of leaf-like bracts surround the bud. The lower, outer row of bracts are broader than the inner ones that are small in the photo. This inner whorl of bracts cohere around the still-closed yellow rays of the flowerhead.

The ray florets of a D. spinosa flowerhead are decorative only, being sterile. The contribution of their marketing services may prevent their evolutionary extinction, similar to what would happen to a marketing department in a business. The reproductive action occurs in the disc.

Spine-tips are clear to see on the spreading outer bracts in picture. So are the bract midribs, deviating from straight and branching irregularly into lateral veins.

There is another bud in the background, its outer bracts not yet spreading. In the open flower the inner bracts are also forced to spread.

Flowering happens from midwinter to early spring (Manning, 2009; Le Roux, et al, 2005; Manning and Goldblatt, 1997).