Petalidium setosum

If you are a Latinist, you have already appreciated the specific epithet for what it means. The dense trichomes that cover the inflorescence bracts give this species its name.

Petalidium setosum is a highly distinctive, scandent shrub that is somewhat ‘special’ among Namibian Petalidium because of its large-ish geographical range… from north central Namibia to extreme southern portions of the country. But wherever it grows, you almost always find it in shallow depressions, indicating it is likely on the needier side of water availability. Its scabrous leaves and its lanceolate (not linear) inflorescence bracts (these densely covered by long, villous trichomes) make this species completely unmistakable.

That is, until you find a hybrid. That’s precisely what we think we found on our May 2014 outing (Essie Klaassen, Iain Darbyshire, Leevi Nanyeni, & Co.) in the Kaokoveld: a population of plants perfectly intermediate between Petalidium setosum and P. halimoides. It had the leaves of the former but lacked their scabrousness. It also had flowers that produced a musky odor, just like those of P. setosum. Yet, these plants had inflorescences of the latter—much denser and with linear bracts. Stay tuned for further study…. never a dull, unless it’s scabrous.

Wild collected, Namibia, Tripp & Dexter #887 (RSA-POM) [and numerous other times]; Photo by Erin Tripp

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