Friday Fabulous Flowers - Olfactory edition

TPP walked into the glasshouse and immediately knew that the taro (Coleocasia esculenta) was in bloom. Generally most people don't notice the distinctive fragrance nor the actual "flower" which hides among the large leaves. This is an aroid, Jack-in-the-pulpit being the best known member of the family here abouts. So, what you really have here is a spike of flowers, an inflorescence known at the spadix,

surrounded by a modified leaf, a bract, known as a spathe. In the case of taro only half the spike is visible; the lower half is pretty tightly enclosed by the spathe. After flowering the upper part of the spike and the upper part of the spathe dry up and fall off. In this particular aroid, the flowers on the base of the spike are "female" and will produce fruits. The upper flowers are pollen producing "male" flowers. You can see the accumulation of pollen around the spike at the "waist" of the spathe. Sterile flowers separate the two and cover the top of the spike. The latter make a lot of fragrance, which is some aroids is a carrion odor. Taro isn't, but the fragrance is hard to describe, sort of a musky, heavy floral odor, not altogether pleasing but not revolting either. Several people noticed the odor today, but hadn't located the source, and it surprised them.  

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.

Largest flower?

Here's another news article about the blooming of the "world's largest flower", and every time this happens, they make the same mistake; the "corpse flower" isn't a flower.  No question about it though, the titan aroid is an amazing plant, and seeing it in flower in person is very impressive.  The flowering structure can be over 6 feet tall, but you'd be more impressed by the odor.  TPP had a smaller species flower in his house a few years back.  It's equivalent structure was about 3 feet tall and on a 2 foot stalk.  It smelled like someone had dragged a cow carcass into out house, so Mrs. Phactor said, "OUT!".  This type of aroid produces the  odor of rotting flesh, a corpse.  This is a giant jack-in-the-pulpit and consists of a cloaking leaf, a spathe, and a spike of lots of little flowers on it called a spadix, some male flowers and some female flowers, and maybe some sterile ones too. All you usually see is the apex of the spike sticking up unless you cut the spathe out of the way.  The flowers are down at the bottom. When flying in toward the carrion, the pollinators, probably beetles, hit the spike and tumble into the funnel formed by the spathe.  So sorry, it's not a flower anymore than a sunflower is a flower.  Curiously the world's largest flower (Rafflesia) is also a carrion flower and it's plant is a complete parasite living under ground except for the flowers.