The plants in the Greenhouse Education and Research Complex, a key component in the Temple Tyler School of Art and Architecture's Landscape Architecture and Horticulture programs, are being diligently cared for at Temple Ambler.
"The fundamental goal is to keep the teaching and research collection alive and thriving for our students, faculty and researchers. Our collection includes many plants that were collected in the wild, as well as rare items that you're not going to easily find and replace," said Benjamin Snyder, Manager of the Greenhouse Education and Research Complex at Temple Ambler. "The Greenhouse, essentially, follows the same guidelines as an animal care facility. We have some wonderful species, such as Bird of Paradise, flowering cacti and lots of orchids, including the coconut pie orchid, which remarkably smells exactly like you think it would."
Snyder, a graduate of the Temple Tyler School of Art and Architecture's Horticulture program, has a particular passion for the oddballs like the coconut pie orchid. The Greenhouse and the Ambler Arboretum don't disappoint when it comes to the fascinating and the strange. The Greenhouse provides a perfect home for an eclectic group of carnivorous plants, spiny cacti of every shape and size, and species that are a great deal more bizarre.
Take the Amorphophallus titanum, the largest "unbranched inflorescence" in the world. The tallest flowers grow to about seven feet in height while the leaves spread a full 12 feet and the tuber weighs in at a monster 150 pounds. Snyder is currently growing several of them, some of which are as tall or taller than he is.
"Our Amorphophallus have been grown from seed donated by Ohio State University in 2017 and Dartmouth College in 2019. You have to be patient with these plants as it typically takes seven to 10 years for them to flower and, in some instances, it can take up to 15 years," Snyder said. "When they bloom, it's truly an event because it's still quite rare in cultivation and the bloom only lasts a couple of days; people will come for miles to see an Amorphophallus bloom."
The fact that it attracts so much in-person interest runs counter to its other most well-known trait — when blooming it smells like death to an eye-watering degree. It's not called a corpse flower for nothing!
"The stench, the speckled maroon and pink coloring, it is this flower's way of attracting pollinators. Rather than bees and butterflies, it attracts anything that would naturally be attracted to rotting meat, such as beetles and flies.
According to Snyder, the Amorphophallus titanum also goes through "thermogenesis." It can generate its own heat to a level that nearly mimics human body temperature, just another way to fool its pollinators.
"It's a technique that isn't unique to the Amorphophallus. Our native skunk cabbage (Symplocarpus foetidus) blooms early; it can melt the snow around the flower," he said. "And yes, as the name suggests, they also stink and rely on flies and beetles as pollinators. They are in the same plant family, Araceae, as the Amorphophallus."
Not too far from the future monstrous blooms, tropical pitcher plants hang innocently enough — unless of course you happen to be an insect. Instead of using them as pollinators, Pitcher Plants have an altogether different use for insects.
"Pitcher plants are meat eaters. While the tropical pitcher plants (Nepthenthes) are not native to Pennsylvania, we have used the hardier Sarracenia in some of our Flower Show exhibits," said Snyder. "The majority of tropical pitcher plants are epiphytes; they do not grow in soil. Typically they attach themselves to tree branches so they aren't deriving nutrients from soil — that's what they get from the insects."
According to Snyder, insects that fall victim to a pitcher plant are essentially succumbing to a slip-and-fall accident. The nectar produced on the underside of the pitcher plant lids attracts the insects. The insects land on the rim/lip of the pitcher, which is naturally slippery; one slip later and it's down the hatch. While the pitcher plant lets insects come to it, the Venus flytrap (Dionaea muscipula) takes a more active role in nabbing a meal.
"There are six trigger hairs inside the 'jaws.' The insect must contact at least two fo these in succession or one twice in 20 seconds to activate the trap, which triggers an electrical signal which tells the flytrap to rapidly move liquid into the cells to close around the insect. This is caused by rapid cell expansion; the plant rapidly fills itself up with water, inflating the cells," Snyder said. "This causes a great deal of stress on the plant — they'll only eat three to four insects in their lifetime. So it may seem fun to let a flytrap close on your finger, but you're actually placing tremendous stress on the plant."
Snyder said while Venus flytraps may seem quite alien, or at least tropical, they are actually native to North Carolina.
"They are hardy, native and carnivorous, similar to Sarracenia and sundews. The sundew (Drosera spp.) is active like a flytrap; they'll entice a fly to pad-like leaf, covered in sticky nectar, and then curl up the leaf with the insect inside," he said. "These are all terrestrial plants that grow in low nutrient, low oxygen, acidic environments, like bogs. They still experience photosynthesis, but supplement that with meat. The slobbering pine uses the same method as the sundew but is native to the Mediterranean region where it prefers dry locations where there is low nutrient, sandy or gravely soil."
Amid the other interesting oddities within the Ambler Campus Greenhouse is a rather unassuming — through massively long — vine, the Tetrastigma, a member of the grape family that in and of itself isn't all that strange. That is until you add in the parasitic Rafflesia, the world's largest single flower, which looks like it would feel right at home in the film Alien or Little Shop of Horrors.
"It has no stem, no leaves, no roots of its own. It only emerges from the Tetrastigma to flower," Snyder said. "It's red and fleshy and, yes, it stinks, and attracts beetles and flies as its pollinators. It is endangered and the location of flowering plants are often closely guarded, but maybe one day you'll find one here in the Greenhouse!"
What you can find in the Greenhouse is hundreds of cacti and succulents, the variety of which almost boggles the mind.
"Spines are usually used for defense. Hairs, however, have multiple uses," Snyder said. "Certain succulents use them for sun protection. There are species native to the Peruvian Andes that use the hairs to collect condensation from fog, often the main source of water in high-elevation deserts Plants find truly amazing ways to adapt to their environments."
Then there are the myrmecophytic plants, or "plants that have symbiotic relationships with ants," Snyder said. There are two in particular in the Greenhouse collection — Tillandsia bulbosa and Hydnophytum formicarum, both obtained from the Botanical Garden of Masarky University, Czech Republic — "that are very bizarre," he said.
"Both have swollen stems full of small cavities and chambers. At maturity, these can be quite large, up to 10 inches wide in Hydnophytum. In nature, these cavities are home to ant colonies," he said. "This symbiotic relationship works in many ways. The ants are provided with a pre-made home, and the plant receives extra nutrients from the waste of the ants. Additionally, the ants protect the plants from herbivores, since nothing wants to eat a plant full of ants!"
Snyder said many of the more interesting species in the Greenhouse collection are used by classes — Plant Physiology for example — to get up close with plants that they might otherwise never experience.
"It's an opportunity for our students and visitors to the Arboretum to see the incredible diversity of plants and their adaptations. You're not going to run into something like the Amorphophallus very often, if ever," he said. "It raises awareness of an interest in nature and the world around us. We have this wonderful collection of fascinating plants — we hope more and more people take advantage of it."
For the home gardener, Snyder said, "many of these weird plants are really quite easy to grow, it is finding them for sale that is hard."
"I think the interest in out-of-the-ordinary plants all goes back to something different, something that stands out from the rest of the greenery. They are great attention-getters — most everyone has seen a bird of paradise flower, but not many have seen a giant corpse flower," he said. "Many of these plants are tropical, or not hardy in an outdoor garden, so these would be treated as houseplants by a home gardener. Of course, the benefit would be having something your neighbor doesn't have!"