Tuesday, July 22, 2008

Amorphophallus Postscript, July 22

Two weeks after flowering, the Titan Arum is not looking so titanic any more. Actually, the stem that supported the inflorescence is still green and solid, even if the rest has collapsed. If the female florets had been pollinated and fruit was set, that stem would stick around for months, with a developing cluster of berries on top. Since we didn't try to do any pollinating, I expect everything apart from the underground corm to deteriorate in short order.

Check out the newly expanded leaf on the young A. titanum plant to the right of the former bloom. This was that skinny shoot that was poking up to the left of the bloom in many of the earlier photos.

Saturday, July 12, 2008

Amorphophallus Postscript, July 12

[Double entendre redacted]

Today was apparently the day for the spadix to lose turgor. That's just four days after opening, and two days after the pollen was shed. Corpse Flowers deteriorate rapidly after they open, which is sort of a shame, since word about a bloom usually gets out to the general public only when it actually opens, and so by the time many people get around to visiting, the inflorescence is already in poor shape. For instance, the biggest crowds came to see this bloom on Wednesday, in the late morning and afternoon, by which time the spathe was pretty well closed up. The short duration of the flowering period does add to the mystique of the Titan Arum, I suppose.

Thursday, July 10, 2008

Corpse Flower Finale

This year's Titan Arum is pretty much done. The spathe is starting to wither, and the spadix is pock-marked with the small pits and bumps that develop when the bloom is spent. Since the inflorescence was not pollinated, the whole aboveground structure will wither away within a few weeks, leaving a tuber that will stay dormant below the soil surface for a couple of months to a year, before sending up a leaf. If we had acquired pollen from another Corpse Flower and applied it to the female florets on the first night, a cluster of red berries containing seeds would have developed.

Just visible on the lower left side of the spathe in the photo above is a hole I cut into the side of the structure, to expose the male a female florets at the base of the spadix for visitors to see. Here's what the interior looked like yesterday afternoon (the day after opening):
The yellow bumps on top are the male florets, and the reddish flask-shaped structures below are the female florets. Pollen hasn't been shed yet, and the females are receptive on the first night, so that self-pollination is unlikely. And that's really the whole point of the giant, stinky flower: it draws in pollinators from a wide area, and some of the insects bring in pollen from other Corpse Flowers, so that the plant can produce seed that isn't inbred.

Today (two days after opening), the same flowers look like the image below:
The stringy, powdery stuff coming from the male flowers is the pollen. I've heard that in the wild, insects tend to get trapped inside of the inflorescence early on, but have an easier time escaping when the bloom starts to wilt, after the pollen has been shed. With a bit of luck, the pollen-covered sweat bees and carrion beetles will not have learned their lesson, and will be lured to another, freshly-opened Corpse Flower somewhere else in the jungle.

That's probably just about it for the Corpse Flower commentary here at Burger's Onion, though I may post a picture or two of the inflorescence's disintegration. Otherwise, plan on a return to the usual schedule of short articles, mostly about funny little South African desert plants, about one per month.

Wednesday, July 9, 2008

Amorphophallus Update, July 9

8:30 this morning.

The Corpse Flower is going down hill fast: the spathe is closing up, and while there is still a pretty funky smell about it, the odor is not nearly as gag-inducing as it was late last night. I stuck around until a little before 1:00 AM, at which point the visitors stopped coming. Up on the ladder, you could feel a current of steamy, fetid air coming off the top of the spadix. I couldn't actually see the evil vapors this time, but on one of the UConn flowers last year, several people reported a visible pale, steamy current drifting off the top of the spadix, around 2:00 in the morning.

We'll be open normal hours (8-4:00) today and the rest of the week. Local TV station Fox 61 had good coverage of the event last night, and NBC 30 had a crew out this morning, for a segment that will appear on their 11:00 AM news.

Tuesday, July 8, 2008

Titan Arum, 11 PM

The Corpse Flower is fully open, and the smell is easily detectable throughout the greenhouse complex, and even outside, in spite of the vents being closed. Sulfurous, overcooked cabbage notes predominate, like the facilities at a rustic campground at the end of August, but there are definite fishy undertones, unpleasantly reminiscent of canned tuna.

In some A. titanum plants, the spathe really opens wide and reflexes, but all three times that this individual has flowered the spathe has been more upright and funnel-shaped. There is quite a bit of variation in this species, even among the subset of plants in botanical gardens. The color of the spathe and the spadix can also vary quite a bit from plant to plant; for example, there are yellow spadices, as with both mature plants at UConn, and also dark purple ones, like this fellow at the U.S. Botanic Garden in Washington.

There's still a steady stream of students, faculty, families and plant enthusiasts coming through the greenhouse. Doors will be open for another hour or so, or you can stop by tomorrow morning and watch the bloom close. It's unlikely that it will open again, and by the end of the week it will probably have collapsed.

Titan Arum in bloom: part 2

Amorphophallus titanum plant #5, nearing fully open at 8:30 PM. The smell is tolerable, so far. The odor comes in waves, and sometimes it is hardly detectable. It's quite pungent at other times; enough to make you gag if you get close and inhale at the wrong time.

A view of the interior, though you can't quite see the individual male and female flowers (they're hidden under a bulge in the base of the spadix). Note the pale spot of variegation on the spadix.

UConn Biology Central Services professional; do not attempt.

Ray and Cherie C. on right. Ravi C. taking a break from the lab on left.

Connecticut people who can't make it in person, check out the TV news tonight. Fox 61 has already shot some footage, and some of the other stations are supposed to do live reports at 10:00 or 11:00.

Amorphophallus titanum in bloom tonight!

As of around 3:00 PM, the spathe started to show signs of pulling away from the spadix. Now it's official: the Corpse Flower is on for tonight. Those of you who are interested in seeing it in person have about eight hours to get to 75 N. Eagleville Rd., Storrs, Ct, 06269, U.S.A. (park in any student or faculty lot, since it's after hours, and make your way around behind the building to the greenhouses). We'll be open to the public until midnight (maybe later, but I promise nothing). Admission is free; B.Y.O. organic vapor respirator.

The greenhouse will be open normal hours tomorrow (8:00-4:00), but you will need to get here tonight if you want the full effect. The photograph here is current: it's early in the process of opening now, and there isn't much smell yet. It will probably be as open as it is going to get around midnight. Any time after 9:00 or 10:00 PM, and you will see the inflorescence in fine form, and be able to inhale as much of the perfume as you can stomach.

Amorphophallus Update, July 8

70.5 inches (179 cm) tall, 1.5 inches taller than yesterday.

Something I hadn't really thought about, until a visitor to the greenhouse during the 2004 Corpse Flower event pointed it out, is that the inflorescences of Amorphophallus are asymmetrical, and can be either right or left handed. That is to say, the spathe wraps around the axis of the bloom, and at the seam either overlaps itself towards the right side (viewer's right, as seen in this photo), or overlaps itself towards the left side. All of the Corpse Flower blooms at UConn (four of them, from two individuals) have been right handed, but left handed blooms do occur, as well. For example, the Smith College 2005 inflorescence and this one at Kew were left handed.

Inspection of the Amorphophallus bulbifer flowers that I posted a photo of last week shows one right handed and one left handed plant in the same pot. These inflorescences are borne on separate corms, but the corms are almost certainly clones of each other, and genetically identical (A. bulbifer reproduces prolifically from offsets, and bulbils that grow from the leaves). So it is likely that handedness is not determined genetically, for at least some Amorphophallus species. I wonder if plants can switch back and forth from year to year? In any event, handedness in Amorphophallus inflorescences seems to be a morphological oddity of little or no biological significance; development proceeds either one way or the other, and there's no functional difference in the end.

Some other instances of handedness in asymmetrical flowers are important for pollination biology. For example, in enantiostylous (Amorphophallus is "enantiospathous" ^_^) flowers, handedness differences probably function to prevent self pollination and encourage outcrossing.

Monday, July 7, 2008

Amorphophallus Update, July 7

69 inches (175 cm) tall, one inch taller than yesterday.

Looks like there won't be any further action from the Corpse Flower today, so my predicted date for the big event is no good. It could be any day now, though, so watch this space.

One of this plant's siblings that I mentioned in an earlier post, the corm that went to Smith College, is going to flower this summer. Check out their web page; they even have a webcam set up.

Sunday, July 6, 2008

Amorphophallus Update, July 6

68 inches (173 cm), 1 inch taller than yesterday.

You would think that you'd need access to an institutional-scale tropical greenhouse to raise your own Amorphophallus titanum to flowering. You'd probably be right. Seedlings or small plants from tissue culture are not all that hard to come by, and seem to go for about $50 to $100. The Huntington has had them for sale in the past, for example, and caveat emptors can usually scare up some offers on EBay (OMG Ultra Rair!!11! HUGE bulbz!). But, getting a mail order seedling up to mature size is not a trivial matter. I've known a number of enthusiastic windowsill growers and hobby greenhouse owners who have tried raising their own Titan, but have yet to hear of any big stinky blooms in someone's living room. One of the smallest facilities that I'm aware of that has succeeded is just the next town over from me in Willimantic, Ct, at Eastern Connecticut State University, where Prof. Ross Koning maintains a modestly-sized hoop house style greenhouse. Fevzi Zeren of New Jersey seems to have succeeded in coaxing a flower from a specimen grown under lights in a basement (one assumes a big basement, and the sort of light setup that earns you periodic visits from the constabulary), though he apparently started with a nearly mature corm.

Corpse Flowers aren't too difficult to please, given a warm, humid, brightly-lit space of sufficient size. Space is usually going to be the limiting factor for a plant with individual leaves 15 feet across and more than one story tall. Other than that, we use a rich, well-drained soilless potting mix, with a bit of lime added, and feed fairly heavily with human blood a balanced water-soluble fertilizer. Ideally, temperatures shouldn't drop below 65 F (18 C), and humidity should stay above 50-60%, though I know for sure that conditions become less tropical than that on a regular basis here at the somewhat antiquated UConn biology greenhouses. The soil should be kept evenly moist at all times, even when the corm is dormant, and the pot should be as big as is practical (the pot for the plant at UConn is cramped, but it's the largest size that can be moved through our doors if need be). The plants need bright light, but leaves can scorch in direct, unfiltered sun. The growth of the plants seems to be only very loosely tied to the seasons: they can have leaves and be actively growing at any time of the year. At least in botanical gardens in temperate climates, though, there seems to be a strong tendency for flowers to bloom in early summer.

Saturday, July 5, 2008

Amorphophallus Update, July 5

Titan Arum at 67 inches (170 cm) tall, two inches taller than yesterday. UConn EEB greenhouse manager Clint Morse for scale.

This individual plant started life as a seed in 1994, from a batch of seed that was collected in the wild in Sumatra by the late James R. Symon, and distributed to various botanical gardens. UConn originally had eight plants [see correction by Clint Morse in the comments], but given space limitations, and the fact that the leaves of Amorphophallus titanum get to be 15 or 20 feet across, all but two plants got donated to other universities (UC Santa Barbara, Washington State U. Pullman, Wellesley, Smith, Duke and Harvard all received UConn Corpse Flowers).

Plant #5, the one still here at UConn about to flower again, first bloomed in July of 2004, at not quite ten years of age, which seems to be about the average time from seed to maturity for this species under glass. Plant #5 flowered again in May 2007, and our other Corpse Flower from 1994 (#3, which has always been a bit of a runt), first flowered in June 2007. Number 3 is the plant with the leaf that's lurking in the background of the photos of the bud, though you can't see it very well in today's image; it's behaving properly and sending up foliage in between blooms. I'd expect #3 to flower again in early 2010. I have no idea when #5 is going to bloom next, after two consecutive flowers.

Friday, July 4, 2008

What's it for?

Amorphophallus titanum, immature inflorescence, with a leaf from a young plant of the same species emerging at right.

I've been giving greenhouse tours to all sorts of groups for quite a few years now, and on more than one occasion--usually prompted by some plant that is completely outside of normal experience, like the Corpse Flower pictured here--a student or garden club member has asked, in these exact words: "But, what's it for?" That's a fairly open ended metaphysical question, but I think that the answer that people are looking for is something practical and immediate, like: "Local people in Sumatra use the leaves for umbrellas." Of course, it isn't really true that anyone uses Amorphophallus titanum to keep out of the rain, as far as I know.

In the absence of known utility for humans, I imagine that it would still be reasonably satisfying for the questioner to hear that, say, elephants eat the leaves, or at least that pretty butterflies visit the flowers. But again, I don't think that anything like that is true of A. titanum: as with other members of the genus, the leaves of the Corpse Flower are probably loaded with calcium oxalate crystals and other toxins. The flowers, famously, broadcast a putrid stench that does not attract charismatic pollinators like butterflies. Even the carrion insects that are drawn by the smell of decay are hapless dupes who receive no obvious benefit from their visit: the blooms merely produce a rotten smell, and yield nothing that a carrion beetle or sweat bee could actually lay eggs in or eat.

It's a safe bet that innumerable bacteria, fungi, mites, nematodes and other tiny organisms do live in association with a Corpse Flower growing in the rain forest. But a tour group is--rightly--not going to be satisfied by: "Well, if it's like other plants that have been studied, there are microbes that live around the roots, feeding on secretions of the root cap. But nobody has ever studied the rhizosphere flora of this species, and probably nobody ever will, unless evidence turns up that something unusual is going on with it. Which it probably won't. Evidence, that is. So yeah, errr, I guess, um, nobody knows for sure." The cute way to answer the "what's it for?" question would be to say "It brings in paying visitors and increases web traffic!" But even if there were an appealing, straightforward, practical purpose for the Corpse Flower (the tubers of related species are edible when suitably processed, for example, and there's no reason to expect that A. titanum would be any different, if it could be cultivated on a large scale), such an answer would be superficial at best, and probably a bit of a dodge, too.

There is a much deeper answer to the question of what the Corpse Flower is for, an answer that yields real insights and productive, testable ideas about why the plant has such peculiar characteristics. It's the answer that Darwin and Wallace gave to the world 150 years ago, almost to the day, for living things in general, not just A. titanum. It's just not tremendously satisfying to the average greenhouse tour-goer. For that matter, because of the workings of human psychology, it probably doesn't have much in the way of purely visceral appeal as an explanation to anyone, even the scientists who have formulated it. But whatever the answer lacks in terms of surface emotional satisfaction, it more than makes up for in pure utility for those who have studied the questions. Because, as far as anyone can tell, Darwin's answer is correct.

The metabolic processes that synthesize the chemicals that give A. titanum blooms their foul odor, the metabolic short circuit that generates the heat to volatilize those chemicals, the tall but thriftily constructed spadix from which the odor wafts into the sultry night air; these and a million other characteristics are what allowed the ancestors of the plant in the University greenhouse to germinate, to grow, to out-compete other plants, to resist herbivores and disease, to exchange pollen, to set and disperse seed. These adaptations permitted the ancestors of our A. titanum, now marooned in Connecticut, to survive and reproduce, century after century, in a teeming rain forest where the competition and the environment were always changing, slowly but inexorably.

What's the Corpse Flower for? It is for making more Corpse Flowers.

Amorphophallus Update, Independence Day '08

65 inches (165 cm), a mere 1.5 inches taller than yesterday.

The Corpse Flower is looking like it's just about ready to do its thing. However,the fact that the spathe hasn't noticeably unfurled compared to its state yesterday, at this point in the middle of the afternoon, indicates that the inflorescence probably won't open up today.

Thursday, July 3, 2008

Amorphophallus Update, July 3

63.5 inches (161 cm), two inches taller than yesterday. Note the flowering Amorphophallus bulbifer plants at the base of the Titan.

The Corpse Flower is getting pretty close to opening; it wouldn't particularly surprise me if it popped for Independence Day. In the closeup of the edge of the spathe at left, you can see that the coloration is getting more intense, and also that the frills are relatively loosely appressed to the spadix, compared to a few days ago. In previous years, the first sure sign that an A. titanum bloom was going to open was a more definite pulling away of the spathe, in the early to mid-afternoon before the flowering. In the closeup, you might also notice some grayish patches on the inflorescence, which is damage from thrips. We've seen this in past flowers, and while it's annoying, the level of damage hasn't been such that we've wanted to risk spraying. Usually, thrips in the UConn greenhouses are knocked down pretty quickly in warmer weather by a predatory insect, Orius, but the orii seem to be slacking off this year.

The greenhouse will be open to the public through the holiday weekend for Titan Arum viewing, until the flowering is finished. Hours are listed on the EEB Greenhouse website. On the day the bloom opens, whenever that is, we'll hang around to let people in at least until midnight. The greenhouses are located behind the Torrey Life Science building, which is 75 North Eagleville Rd, Storrs, Ct 06269.

Wednesday, July 2, 2008

Amorphophallus Update, July 2

61.5 inches (156 cm), two inches taller than yesterday.

There was a nasty smell in the greenhouses this morning, and I was momentarily worried that the Titan had decided to flower last night, and that I had missed it. A bit of hunting turned up the real source, though: several plants of Amorphophallus bulbifer were in bloom. These plants are much smaller than A. titanum, with blooms only about eight inches tall, but they give off a penetrating odor of outhouse, overcooked cabbage and dead animal that is actually fairly close to the smell of the Corpse Flower, qualitatively if not quantitatively. In the A. bulbifer photo below, you can make out the female florets (globose structures at the very base of the spadix, inflorescence on the right) and the male florets (pale fuzzy zone directly above the female florets).
Amorphophallus bulbifer.

The blooms of different Amorphophallus species produce quite a variety of odors. Amorphophallus titanum, A. bulbifer and A. prainii are sulfurous and cabbagey, while A. konjac and A. paeonifolius have a more straightforward dead-rat-in-the-wall smell. Amorphophallus odoratus has a funny, almost artificial smell, sort of like deodorant. These odors attract various sorts of insect pollinators, often flies or other carrion feeders, who are tricked into thinking they've found a meal. In its native Sumatra, the primary pollinators of A. titanum are apparently sweat bees.

Tuesday, July 1, 2008

Amorphophallus Update, July 1

59.5 inches (151 cm) tall this morning, which is three inches taller than yesterday.

Aside from a slowdown in the rate of growth, another indication that flowering is not far off in A. titanum is the development of reddish coloration on the inside (adaxial side) of the spathe. In the closeup photo, you can see some purple/red coloration where the frills at the edge of the spathe have curled over. I first noticed a little color in the spathe yesterday, and it's more obvious today. Things are looking good for a bloom early next week.

The spathe, by the way, is an often petal-like leaf that subtends the rest of the inflorescence in members of the Araceae (the Jack-in-the-Pulpit or aroid family), to which Amorphophallus belongs. As with other aroids, the "flower" of the Corpse Flower is really a highly modified flowering shoot, or inflorescence, comprising the spathe, a modified stem called the spadix (the part that puts the phallus in Amorphophallus), and numerous small male and female flowers hidden inside the spathe at the base of the spadix. The spathe/spadix structure in A. titanum does look very much like a single flower, and functions like a single flower to attract pollinators, so even a plant morphology nerd like myself doesn't have too many issues with just calling the thing a flower. If you want to get technical about it, though, A. titanum has the largest compact flower-like inflorescence in the plant kingdom. The largest simple blooms occur in a totally unrelated genus of Southeast Asian carrion flowers: Rafflesia.