A damned big Jack-in-the-pulpit

If you've never seen, or smelled, an Amorphophallus in flower, it's something to see (see if you can figure out the name).  Like all aroids, this isn't a flower, but an inflorescence and a modified leaf, a bract, in the terminology of the family, a spadix and a spathe.  Hundreds of unisexual flowers are hidden from view at the base of the spadix.  This is the titan, the largest such inflorescence in the world at 2+ meters tall.  TPP once had a smaller species bloom in his house, not exactly a planned event, but the basketball sized corm was being overwintered when it flowered.  This smaller species had an inflorescence just a bit over a meter tall and it was raised on a half-meter stalk.  The fragrance produced lures in pollinators, beetles and flies, and it smells like rotting flesh, carrion.  The pollinators use carrion for a brood substrate, which is not provided, so they are cruelly deceived by the plant. Beetles are particularly fun because as the beetles fly in they more or less fly directly into the pylon that is the spadix, and as the fall, the funnel like spathe dumps them down to the bottom where the female flowers are located, ready to be pollinated provided that the beetles have chanced upon another such aroid a bit earlier.  At any rate these are a lot of fun to see, in someone else's greenhouse. Many of these inflorescences also heat up, a mechanism for dispersing more of their attractant odor. Jolly good fun for the whole family.  Aroids aren't the only flowers that use such pollinators (see here, here, and here), aroids are just the most famous.

Rainforest Field Trip - When is a flower open?

Generally speaking just about any 5th grader could tell you when a flower is open, but as some of my students learned, that isn't always so easy. Here's a member of the Annonaceae, the custard apple family, Guatteria diospyroides, that demonstrates my point. Don't most of these flowers look open? And the circled ones look closed, but these closed flowers looked just like the open ones just a couple of days ato. The flower buds get bigger and then the perianth parts open, 3 whorls of 3 tepals, of which you can readily see the inner two whorls. The open tepals expose a "button" that consists of a large number of flat, "leafy" stamens closely appressed to each other and tightly surrounding a cluster of pistils. This takes a couple of days and the flower sure does look open, but there is no fragrance, the pistils are not receptive, and no pollen is being shed. After another couple of days the inner whorl of tepals begins closing again until they are pressed up against each other leaving a small opening in the center (two circled flowers). Now this flower is "open" in the sense that it now emits an odor, a tropical fruity smell plus nail polish remover, and the pistils are glistening and receptive. At the end of that day the perianth opening completely closes, and no one enters or leaves for another day at which time the stamens finally shed their pollen and shatter falling into the perianth chamber. Flowering is now over and the inner two whorls of perianth are shed leaving only the sepaloid outer whorl and the pistils; this releases any pollinator held within. It takes a lot of marking and observation to figure this out, but it gets even more complicated when you notice that all the "open" flowers on the tree are in sync, either pollen accepting or pollen dispersing, tick-tock, every other day. Trees that are ticking get pollinated by trees that are tocking, back and forth, day after day throughout the flowering season, as beetles move from tree to tree seeking a food reward. If these trees are like some of their relatives in SE Asia then all the trees that are ticking or tocking will be the same year after year. Bet that will take my students a long time to figure out, but right now some of them like the idea of staying here.