Strolling Through Sonnenberg: Things are Heating up in the Greenhouse

If you have visited our greenhouses recently you may have been treated to a rare sight. Our tree philodendron (Philodendron bipinnatifidum; syn. Philodendron selloum) is in bloom. Actually, more than one of them are currently in bloom. Our gardeners say they have never seen them in bloom. And many people, who keep these as houseplants, have never either for this plant must be large in size and at least 15 - 20 years old to flower.

Philodendron bipinnatifidum flower

The flower of this plant may remind our visitors of other Araceae family members - like our native wildflower jack-in-the-pulpit (Arisaema triphyllum) - for the flower has a sheath-like bract or hood called a spathe and a fleshy stem with the flower cluster called a spadix.

Confused? They say a picture is worth a 1,000 words so check out the labeled picture to the right. Other tree philodendron flower vital stats: the flowers are typically over 1 foot long, contain about 3000 white "florets" on the spadix or stalk, and last only two days.

The tree philodendron is monoecious which means the flowers have both male and female structures. The male flowers are located on the top half of the spadix, while the middle region contains sterile male flowers, and the female flowers are located at the base. As you can see by the pictures in the gallery below, the flowers are not very showy and can be missed if not looking for them. So just how does this plant attract its pollinators?

This plant has an unusual hook for its pollinators. It has heat-producing or thermogenic flowers that when they heat up causes a pheromone to be released. This pheromone attracts Cyclocephala beetles, which are a New World scarab beetle genus. The flower then provides them with heat and nectar for two days before forcing them out (by the action of the flower closing). Covered in pollen, the beetles move onto the next flower where they pollinate it.

What is most astonishing to botanists and scientists, is that this plant can raise the temperature of the spadix to 104-113 degrees F and hold it to a constant temperature regardless of the ambient air temperature which may fluctuate from 40 - 80 degrees F. The flowers can actually feel hot to the touch. This degree of temperature regulation is unheard of in the plant world.

Be sure to visit Sonnenberg soon to see these amazing flowers for yourself. If you can't make the visit, read more below and enjoy our gallery of images at the end of this article.

References & More Study Available at:

http://biologicalexceptions.blogspot.com/2011_10_01_archive.html
http://faculty.ucc.edu/biology-ombrello/pow/Philodendron.htm
http://biologicalexceptions.blogspot.com/2011/10/is-it-hot-in-here-or-is-it-just-my.html
http://www.damninteresting.com/warm-blooded-plants/

Gallery:

Click on the images below to see the larger, full-sized image.