Senecio spiraeifolius fruiting stages

Some stages of the Senecio spiraeifolius fruiting sequence are depicted here. The plant was photographed in the Biedouw Valley during September.

The green involucral cup at the lower end of the flowerhead is flat-based, followed by a brief, widening ring, a short conic section that ends where the parallel bracts begin. These involucral bracts neatly cohere while sloping inwards to their tips, concealed under the shrivelled ray floret remains.

On the older head in the picture centre the white, straight fruit pappus hairs are conspicuous on the upper ends of the about cylindrical fruits that depend upon wind for their dispersal.

After dispersal, the oldest heads of the season have their involucral bracts flexed down completely below the outer rim of the shallow, bare, dome-shaped flowerhead receptacles. The involucral bracts assume this position on cue when the fruits ripen for neither impairing the pappuses in spreading, nor the fruit departures once they are ready for flight.

There is one empty head with bracts still angled up in a shallow bowl, while the head full of pappus-dominated fruits already has its involucre pointing all bracts downward.

The upper surfaces of the dome-shaped receptacles are dotted with neatly arranged indentations in which the individual disc florets once stood erectly before they became fruit.

Once these rocket-like structures stand bare like this, the annual sequence of the plant’s reproductive ritual is complete. The stems will gradually disappear, making space for another, similar show of flowers, fruits and seeds re-enacted next year, weather permitting (Manning, 2009; Manning and Goldblatt, 1997; iNaturalist).