Titan arum bloom at Appalachian State University

Maybe inspired by Halloween, Mongo the resident corpse flower (aka titan arum, Amorphophallus titanum) at the Biology Greenhouse at Appalachian State University sent up a flower bud for its first bloom in early November this year. It took over a decade to grow to this stage from a fist-sized corm received as a gift from the Atlanta Botanical Garden. After teasing us for a while with a bit of stop-and-grow (probably responding to light conditions), it finally blossomed the day after Thanksgiving. Pictures and a timeline of the bloom progression are available on Mongo's website.

Mongo in all its smelly glory shortly after midnight in the early morning hours of Nov. 25, 2023. It grew to a little over four feet tall.

This plant species is famous for making the largest unbranched inflorescence known and is endangered in the wild with fewer than a thousand individuals left in its native range on Sumatra. Being such a prominent record holder in the plant kingdom, it is however a flagship species for botanic gardens and cultivated around the world. As a tropical rainforest plant of sizable stature, it is not suitable as a houseplant though and its cultivation requires a greenhouse facility that can accommodate its high temperature and humidity needs. It takes a decade or longer to grow from seed to blooming plant, and once it reaches maturity it will bloom only for a few days every couple of years. Every one of these blooms attracts a crowd of admirers. An estimated 3,000 people turned out to see (and smell) this botanical marvel up close and personal at AppState. Almost everyone took pictures, but curiously I'm the only one who has uploaded any on iNaturalist. Well, I tried to make up for it by uploading nearly a dozen observations to cover this event. I hope y'all forgive my botanical nerdiness! (It also taught iNat that this plant is cultivated in this location, so any future uploads should be automatically marked not wild.)

Botanist delight - not sure what was more exciting: Mongo's bloom or seeing how many people showed up and waited in line in the freezing cold for up to an hour just to see a plant!

Great to see so many youngsters get excited about a stinky flower. Mongo had fans coming back several times. Great pictures, I'd say!

Being a family member of the Araceae, the inflorescence takes the shape of a spadix (central column) with a surrounding spathe (frilly skirt). It produces both warmth and stench to attract its pollinators (flies and carrion beetles) by mimicking the looks and smell of something dead and decomposing, hence its nickname corpse flower. Its distinctive odor is said to be the strongest in the early morning hours of the day of its bloom. Having personally witnessed the bloom and talked to our greenhouse manager, who came in just as I was leaving after midnight, Mongo was at its stinkiest around 1-2 AM after the spathe unfurled. I thought it smelled more fishy than rotting meat. The smell does linger - I felt I kept smelling it for days, possibly hanging onto my clothes or maybe just my imagination.

We did have a few interested costumers checking things out. Hidden inside the vase-like spathe at the very base of the spadix are the actual flowers, a ring of males with stamens on the top and another ring of females with carpels below.

Our greenhouse manager cut a window into the base of the spathe to open up a view inside. The female flowers are the purple-reddish pegs on the bottom and the male flowers are the yellow bumps on the top.

The plant prevents self-pollination by maturing its female flowers during the first day while oozing the pollinator-attracting stench. The male flowers will release their pollen strands a day later once the females are no longer receptive to pollination. We tried to acquire pollen but were unsuccessful. Apparently it requires high humidity to mature, and cutting a window as well as opening and closing the door as visitors came through probably prevented the conditions to be right for pollen release. We did take a few samples for microscopy.

Removing some florets to preserve in glutaraldehyde for microscopy.

Now we may have to wait for another couple of years for the next opportunity. Given the proper care, it should be even bigger and smellier than this first bloom!

Publicado el 20 de diciembre de 2023 a las 01:29 AM por annkatrinrose