Listen to part of a lecture in a botany class.
Hi, everyone. Okay. Today, I will lecture on some pretty strange plants. As a matter of fact, the plants we will discuss are from the family Rafflesia, a parasitic plant. So, without further delay, I will begin. The Rafflesia is a genus of parasitic flowering plants. It contains, um ...15-19 species, all found in southeastern Asia, let's see, on the Malay Peninsula, Borneo, Sumatra, West Malaysia, and the Philippines. The flowers have no leaves and hardly any stem, just a huge, speckled, fivepetal flower with a diameter of up to 106 cm, and it weighs up to 10 kg. Even the smallest species, um, R. manillana, has 15-inch-diameter flowers. The flowers smell like rotting meat, so we get certain local names for these plants which translate to, um, "corpse flower" or "meat flower." The vile smell that the flower gives off can sometimes attract flies, which these plants use as a food source. Additionally, it is parasitic on vines In the genus Vitaceae, spreading its roots inside the vine. Now, let's talk about specific varieties of Aafflesia. I'll begin with the Nepenthes rafflesiana, a species of pitcher plant named after Stamford Raffles, the founder of Singapore. This plant has a very wide distribution covering, um, Borneo, Sumatra, Peninsular Malaysia, and Singapore. N. raffle-slana is extremely variable with numerous forms and varieties. For example, in Borneo alone, there are at least four distinct varieties. The most impressive form, known as N. rafflesiana gigantea, produces enormous pitchers. These pitchers, or heavily modified ¡¤leaves, are used to capture and kill insect prey for nutrients.
Well, like it or not, all Nepenthes are, um, passive carnivores. They are classified passive because they have no moving parts, unlike their distant cousins the Venus flytrap, an active carnivore. Okay ... So the N. rafflesiana kills by luring its prey into its, ah, pitchers, whose peristomes secrete sweet-tasting nectar. Once the insect is inside, it quickly finds the walls of the pitcher too slippery to scale and, as you may expect,drowns. Digestive enzymes released by the plant into the liquid break down the prey and, um, release soluble nutrients, which are absorbed by the plant through the walls of the pitcher. The carnivorous nature of Nepenthes is supposedly a consequence of, um, living in nutrient-poor soils since the main method of nutrient absorption in most plants, the root, is insufficient in these soils, so the plants have evolved other ways to gain nutrients. Let's see, yes, finally, N. rafflesiana enjoys hot, humid conditions most of the time, as found in tropical jungle lowlands.
Okay, so far so good. The next plant I will discuss is the, um ... where are my notes, ah, here we go, Rafflesia arnoldii, another member of the genus Rafflesia. Not only is it the world's largest flower, but it is also one of the most bizarre and improbable organisms on the planet. There are some plants with larger flowering organs, for example, the Titan Arum and Talipot, but these are technically clusters of many flowers. Rafflesia arnoldii is the largest, and you can take this to the bank, because its flower attains a diameter of nearly three feet and can weigh up to, get this, 24 pounds!
It lives as a parasite on the Tetra Stigma vine, as its host, which grows only in undisturbed rainforests. White many parasites appear like normal plants, um, Rafflesia lacks any observable leaves, roots, or even stems, and this is what makes it so strange. A lot like fungi, Rafflesia individuals grow as thread-like strands of tissue completely embedded within and in intimate contact with surrounding host cells from which, um, nutrients and water are obtained. The only part of Rafflesia that is identifiable as distinctly plant-like are the, ah, flowers, although even these are bizarre because they attain a massive size and are usually reddish-brown and stink of rotting flesh. The flower is pollinated by, uh, oh my goodness, flies ... which are attracted by its scent. Aafflesia arnoldii is very rare and fairly hard to locate. It is especially difficult to see in flower because the buds take many months to develop, and the flower lasts for just a few days.