University of Washington Greenhouse

April 3, 2012

We spent this day at the greenhouse at three stations; one specifically about chili, and the other two about plants found around the world. The botany greenhouse hold 1/10 of all diversity of plants on earth. There are "domes" of desert to tropical forests.

The first rotation included a lesson on carnivorous plants. Each pot containing different species are placed in a bog-like area, surrounded by sphagnum moss which is acidic and contain low nutrients. The venus flytrap secretes digestive juices to digest insects that land on the mouth of the trap. The stimulus to the trap closing is movement, not heat. A plant belonging to the sarracenia family has a large mouth and deep, hallow pitcher. The inside of the pitcher contain hairs that points downward essentially to trap insects that fly in. Finally, the drosera filiformis opens flat and has a surface that looks like morning dew that insects stick to if they land on it. The platycerium is a large plant that has biomorphic leaves and a shield to hug the interior. It has a foliage to add water, funneled into plant. The inside leaves that are older decompose itself to create nutrients so essentially, the plant feeds itself. One of my favorite was the dracula orchird that have gills to attract fungus. Insects lay their eggs on the plant and in turn the plant gives it pollen to pollinate. One of the larger species in the greenhouse is the welwitschia. This plant comes from the harshest of deserts. It is a gymnosperm (conifers) and a conquerer. It bears cones, can be male or female, and grows at a rate of 25mm a year. These plants can be up to 2000 yrs. old. It stores its own water for most of the year to survive. Our greenhouse "curator" actually provided this plant with more water than it receives in the wild, and it is happily thriving. One of the interesting aspect of the plant is that there is still no one who understands how its seeds are dispersed.

The second rotation was a fun lesson with miracle berries and chili. Miracle berries (common name) exists as a tropical plant that blooms in the northern hemisphere fall season. The berries are edible, but they aren't sweet. They do however change your taste for about an hour. The chemistry in this plant much like many other berry plants are created for a specific species, the species that pollinate it. If you suck out the juices of the berries and give it a light rinse around your mouth, then stick a slice of lemon in your mouth, you'll find it tastes sweeter and sweeter with every slice. These compounds masks the sour taste in lemons that humans observed. Those compounds exists in other plants as well such as chili. To birds, chili's pollinators, the plant doesn't taste spicy. The ghost chili which has capsaicin and is coated with olive oil is on of the hottest chili known to man. The spiciness you taste in chilies actually aren't what you taste. Chilies mainly affect your neurotransmitters, the same kind that tells your body to take your hand off a hot stove. Birds that pollinate chilies plants reflect capsaicin in their nerves which makes them feel no pain, or to humans the spiciness. One of the questions our professor spent his research on was, "Why aren't all chilies hot?" Well, hot chilies do not produce as much seeds in drought therefore they have selective niches. A little history i didn't know was that the Portuguese moved chilies around the world; before then chilies didn't exist anywhere else but the tropics. The advantage is that chilies are antimicrobial which is great in the tropics. (see page 9 of field notebook for sketches)

Posted on June 5, 2012 03:46 PM by lhuynh10