SUCCULENT SUNDAY: Adenia stylosa, purple vine of evil

Also posted at SentientMeat.net

Adenia stylosa, photo by Mr Sentient Meat of his plant

Okay, maybe Adenia stylosa isn't truly evil. But its heart-shaped purplish leaves are the color of a deep wound. They do have dark red veins. And consider the stem... the gnarled, waxy, green, enlarged trunk or caudex. To me it looks like a living version of a melted candle destined for a Satanic ritual. In fact this plant's common name is reportedly "Candlestick Plant". That's fitting, as far as it goes. It does lack a bit of punch, a bit of drama. I think we should all start calling it "Satan's Candle". Who will be the wiser? Common names don't really matter anyway. Whatever you call it, it's a plant straight out of Charles Addams or Edward Gorey.

Adenia firingalavensis v. stylosa "Candlestick Plant"

Now to the anatomy of evil... or at least the secrets behind Adenia stylosa's macabre appearance. Its above-ground tuber... okay, "tuber" doesn't sound very evil... this caudex even has vaguely anatomical "hips": actually a distinctly swollen hypocotyl, the portion of the stem below where its cotyledons were attached and fell away in the seedling's infancy. The leaves are dark and attractive, varying between individuals as shown in this picture by Olaf Pronk.

Leaves from different individuals, all Adenia stylosa

Adenia stylosa was known previously as a subspecies of Adenia firingalavensis or Adenia epigea but is now considered a separate species. It lives in Northern Madagascar, in Ankarana National Park among other places.

Famed tsingy, limestone formations in Ankarana, Madagascar

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See also:
Rauh, Werner. Succulent and Xerophytic Plants of Madagascar. Strawberry Press.

1995. Volume 1. ISBN 10: 0912647140. ISBN 13: 9780912647142

1998. Volume 2. ISBN 10: 0912647175. ISBN 13: 9780912647173

David J. Hearn has found strong enough DNA evidence and differences in its form to separate Adenia stylosa as a distinct species, moving it from its historical classification as variations or subspecies of Adenia firingalavensis or Adenia epigea. From the scientists' abstract:

[T]he position of A. stylosa has been clarified. This species was once treated as A. firingalavensis var. stylosa, and prior to that as A. epigea var. stylosa, but molecular and morphological data suggest it is separate from these species.

Hearn, D. J. 2007. Novelties in Adenia (Passifloraceae): Four new species, a new combination, a vegetative key, and diagnostic characters for known Madagascan species. Brittonia 59(4): 308–327.

Huntington Botanical Garden's introduction of related Adenia epigea