Biology 213
Name:__________________________________________
“Lab” 6: Visiting the University of Washington
Greenhouse
Introduction: The Biology Greenhouse at the University of Washington is used for both teaching and
research. The greenhouse was built in 1949 and has been substantially expanded and remodeled in the
time since. The greenhouse consists of several rooms that house types of plants; four of these rooms are
open to the general public. Each of these rooms will be described in more detail in the sections that follow.
You can read more about the UW greenhouse and its 2000+ species of plants at
http://www.biology.washington.edu/greenhouse/.
Greenhouse Etiquette: We are guests here! Please follow the rules below.
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Please place all large backpacks and coats on the rack in near the main entrance. (But don’t leave
valuables unattended here!)
Try to avoid knocking over pots or otherwise damaging the plants.
Many of the plants can be damaged by even your fingerprints, especially the stone plants. Please
don’t touch them without asking!
Our Tour: Room 7
We’ll start our tour in the first room to your right as you enter, the desert room. Most of the plants here are
perennial xerophytes, plants adapted to living in a dry environment. As you look around the room, many of
the plants will look like closely related cacti (members of the plant family, Cactaceae). But check out the
labels! The plants represented here are from many different families, providing a powerful example of
convergent evolution.
1. Identify at least three adaptations you observe that help these xerophytic plants cope with their harsh
environments. Briefly describe the function of each adaptation you identify.
Not to miss: Be sure to watch for the unusual stone plant. These plants grow almost
entirely submerged in the coil in some of the world’s hottest and driest deserts. The tips
of the leaves lack chloroplasts, allowing light to enter through these transparent regions,
reducing the amount of light (and heat and drying) the plant is exposed to. These
“stones” crack open when conditions are favorable, producing remarkably large
flowers!
Our Tour: Room 2
We’ll head across the hall to a dramatically different environment, the bog! In this room, you’ll find a large
collection of ferns, liverworts, and several different carnivorous plants. This room is much cooler (55 F) as is
required by the high altitude orchids kept in this room.
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2. What challenges does life in a bog present to plants?
Not to miss: Be sure to check out the cobra lilies (Darlingtonia californica)! These carnivorous plants trap
insects in their long, hollow stems.
This room is also a great place to explore the largest plant family, the orchids. Roughly 20,000 different
species of orchids are known; roughly half of these live on other plants as epiphytes. In general, orchid
flowers are quite showy and heavily scented to help attract specific pollinators. Because their relationship
with their pollinators are so specifically, the flowers can be quite long lasting, often surviving for weeks or
even months if pollination doesn’t happen. They also use swollen stem segments called pseudobulbs to
help store water. You may also notice the thick, white tissue that covers their air roots, the velamen.
Velamen acts as a sponge allowing the roots to absorb water from the moist air of a tropical forest.
3. While in this room, be sure to check out the ferns and bryophytes! Explore and find a good example of
each. Sketch the plants, providing a scale bar, the full scientific name of the plant you choose, and noting
any key features on your sketch.
Fern:
Bryophyte:
Are the plants you’ve drawn haploid or diploid? Sporophytes or gametophytes?
Not to miss: Be sure to check out the tree ferns (Cyatheales). These very large ferns form “trunks” and can
reach 80 feet in height!!
4. Do these ferns have vascular tissue? How do you know??
Our Tour: Room 5
From the bog, we’ll head back to the first tropical plant room. These plants face a very different set of
challenges. Water, for example, is rarely limiting. Thus we don’t expect to see adaptations to conserve
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water. May of these plants, in fact, have “drip tips” and other adaptations that help them get rid of excess
water! Temperatures are generally mild, allowing these plants to grow year around (as “evergreen” plants).
This abundance of water and mild temperatures doesn’t mean life is easy! Tropical plants compete
intensely for light and must tolerate surprisingly poor soils.
5. Explore this room, looking at the adaptations that help these plants deal with the lack of light on the forest
floor, and the nutrient poor soils. In the space below, describe two adaptations you observe that help plants
meet these challenges.
6. Watch for “Spanish moss” in this room (Tillandsia usneoides). This tropical epiphyte is
common in the southeast U.S., too, where it’s often found hanging from branches and
telephone wires. It’s also a nice opportunity to highlight the pitfalls of common names.
While “Spanish moss” usually reproduces asexually through fragmentation, it does
occasionally flower!!
Is this plant really a “moss”? If not, which phylum does it belong to? And does that make it haploid
or diploid? Sporophyte or gametophyte?
This is also a great room to think about coevolution. Watch, for example, for the Acacia. These thorny
plants have tiny yellow dots on the leaves that serve as nectaries for ants.
7. Use the Acacia plants to explain coevolution in your own words.
After watching Sexual Encounters of the Floral Kind you won’t want to miss the water
lilies growing in this room! Remember that the water lily flowers are open for only two
days each. On the first day, a pool of liquid is seen in the center of the flower. Insects
carrying pollen fall into the pool and dies. On the second day, the pool is gone and
the pollen-producing anthers ripen.
8. Where do you expect the stigma to be located on this flower? Why?
9. What benefit does the lily achieve from this careful timing?
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The Last Stop on Our Tour: Room 6
The last room we’ll visit today contains more tropical plants! You might recognize
several common house plants here, including the philodendrons, and Monstera
deliciosa.
10. What function do the holes in the Monstera leaves serve?
11. What other adaptations do you notice as you explore the plants in this room?
12. Recall that tropical systems are some of the most diverse in the world! While an acre of our forest here
in the northwest may have only a few dozen different species of plants, a single acre in the tropics may
have 100 species of just trees! As you explore the two tropical rooms, think about the four major groups of
plants we’ve discussed. Which ones are best represented here? What does this suggest about their overall
abundance on Earth today?
This room also houses the well-named Amorphophallus. This odd plant exists for most of the year as a corm
(swollen stem) with one or more large leaves. Eventually the leaves die and the corm produces one huge,
stinky flower! (The stinky flower, as you might guess, is pollinated by carrion beetles!) Sadly, it probably won’t
be blooming during our visit, but is definitely worth checking out in bloom if you ever get the chance!
Other interesting plants here include banana plant (Musa sp.). These are wild bananas and have small red
fruits on them! Coffee lovers should watch for their favorites here, too!
Postlab Assignment: In addition to this handout, please select one of the plants we see on our tour to follow
up on. Your postlab should consist of a picture of the plant, and 1-2 paragraphs describing its unique
features. Feel free to pick anything that catches your interest on the tour! (Note that almost all the plants
have their scientific names listed on tags in the pots, making them easy to investigate.) Bring a camera, or
let Ann know if you’d like her to take a picture of a particular plant for you! Be sure to take some notes
today and write down the scientific name of the plant you’ll follow up on in the space below:
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