Introduction

Like us, trees have names and are organized into families. Most of the families are arranged so that similar trees are grouped, or related. This usually means that trees with similar characters like leaf shape, flower patterns, bark, and fruit type are put together. We call this idea of grouping things at different levels a hierarchy. We use hierarchies all the time to explain the order of things. Consider your family tree or the way our government is set up with the President at the top. We use this concept of ordering to organize all living things because to understand and study our natural world, we need a way to understand how they are related.

To organize living things, a specific name is assigned that is made of two parts, the genus name and the specific epithet. Together these two names make the species name and we refer to this type of naming as binomial nomenclature. These names are in Latin, which helped to standardize the names for living things around the world. Most living things also have common names, but these can vary across different cultures making it confusing at times. The Latin name given to a species usually reflects something about its character or is named after the person that discovered it. We define species names through writing descriptions of what they look like, including any sort of expressive term like measurements and color that distinguishes this species from the next. We will include common names with the scientific names in the activity. Wouldn’t you like to have something named after you that would be recorded forever?

We would like to introduce a gymnosperm family, or trees with “naked seeds,” and an angiosperm family, or flowering producing trees as the two examples for this lesson. The Pinaceae, or Pine family is commonly considered to be evergreen because of their needle-like leaves and the Fagaceae, or Oak family is considered to be deciduous because they lose their leaves in the winter. These are two of the plant families represented in the tree collection of the Smithsonian Gardens and will give you an idea of how trees are named.

A Tree of Trees: What’s in a name?

Family hierarchy: Example: Family name Pinaceae Species name (2 parts) Pinus virginiana Genus Pinus Specific epithet virginiana

www.gardens.si.edu

Learning Goals:

Students will learn about scientific inquiry and how things are related and grouped together, or put into a hierarchy

Strengthen classification and organizational

skills

Learn how to use a dichotomous key

Use measuring tools to compare and order

things

What you’ll need: Activity sheet with pictures Notebook/ paper Colored pencils Ruler Magnifying glass or small hand-lens Camera (if possible for the teacher)

Useful sources:

A plant key or flora of your area

The Names of Plants. By David Gledhill.

Cambridge University Press, 4th

Ed. 2008.

Botanical Latin. By William T. Stearn. Oregon,

Timber Press, 2004.

Fact Sheets:

USDA Plants: www.plants.usda.gov

Virginia Tech, Dept. of Forest Resources and

Environmental Conservation:

http://dendro.cnre.vt.edu/dendrology/factsheets.cfm

For younger students

I can name 50 trees today!: All about Trees. By

Bonnie Worth. Random House, 2006.

Vocabulary

• Scientific name

• Hierarchy

• Gymnosperm

• Angiosperm

• Dichotomous Key

• Flora

A Tree of Trees: What’s in a name?

www.gardens.si.edu

A Tree of Trees: What’s in a name?

Activity:

In the classroom or at home: Read introduction and review vocabulary. Discuss what it means to classify, or group things together and introduce what a dichotomous key is and how it is can be used to help identify organisms. These keys are similar to a “chose your own adventure,” because you have questions and make choices that lead to the next step. * Next discuss how all living things are grouped together and given names, similar to the way we are named. Discuss how humans’ scientific Latin name is Homo sapiens and how our common name is our given family name, like George Washington. Explain that one level of grouping is considered to be a family, the next level a genus, and the last level the specific epithet. The genus and specific epithet name form the species name. Share the two plant family trees from this lesson with your students and go over the definitions of the Latin names. Please note that these are two examples of plant hierarchies, and examples from the Smithsonian Gardens, but there are more names that would normally be on the family trees for both families. Have students complete the activity using the dichotomous key to figure out the names of the pine and oak trees from the images provided. Get outside: Use the images provided to go out and find a pine or oak around your school or community. Or explore the grounds of the Smithsonian Gardens and see if you can locate some of the trees indicated on the family trees in this lesson. The trees used here are located in the following gardens: NMNH, RIPLEY, HSG, NMAI, and HAUPT. Use the map of the garden to find your way.

Outside Activity: First, find a shady spot under a tree and have students group themselves together depending on height. They can decide how many groups to make. Next, they can divide their groups into subgroups depending on hair color and then by shoe size. Finally, come up with a name in two parts that describes your group. Have each group share their hierarchy with the rest of the class. Ask these questions:

o Do you see how this is similar to the Pine and Oak family tree examples?

o Do you see how we use characters to organize and group things together?

For Teachers: Answers for the following activity sheets.

* Review plant descriptions and introduce terms for parts of trees

www.gardens.si.edu

Pinaceae Family: 1 – Pinus bungeana, 2 – P. virginiana, 3 – P. thunbergii, 4 – P. cembra, 5 – P. pinea

Fagaceae Family: 1 – Quercus alba, 2 – Q. palustris, 3 – Q. phellos, 4 – Q. bicolor, 5 – Q. rubra

Latin Name Common Name

Meaning

Cedrus cedar the ancient Greek name, for a resinous tree with fragrant wood

deodara divine tree

Picea spruce Pitch (the ancient Latin name, pix, refers to the resinous product)

omorika from the Serbian name for Picea omorika

pungens ending in a sharp point, pricking

Pinus pine the ancient Latin name, pinus, for a cone-bearing tree

bungeana lace bark pine for A. von Bunge (1813-66), herbalist of Kiev, Ukraine

cembra the old Italian name for the arolla or Swiss stone pine; some derive it from German, Zimmer, a room

pinea cone-producing, of pines, resembling a pine

thunbergii for Carl Per Thungberg (1743-1822), Swedish physician and professor at Uppsala, who travelled in Africa, Japan and Batavia

virginiana Virginia pine from Virginia, USA

Dichotomous Key activity: Use the dichotomous key to determine what five pine species are in each picture.

Dichotomous Key to the Pines (Pinus) from the Pinaceae tree

A. Are the needles single in whorls around the branch…………. Pinus pinea

A. Are the needles clustered, or bundled (fascicle)…………….. Go to B

B. Are the needles clustered, or bundled in groups of 2 ………….. Go to C

B. Are the needles clustered, or bundled in groups of 3 or more … Go to D

C. Are the cones on your tree broad, egg-shaped and 5-7.6 cm long … Pinus virginiana

C. Are the cones on your tree found at the end of the branch, symmetrical

and 4-7 cm long ……………………………………………………………………Pinus thunbergii

D. Are the needles clustered, or bundled in groups of 3 …………… Pinus bungeana

D. Are the needles clustered, or bundled in groups of more than 3 …. Pinus cembra (5

per bundle)

Tip: Use the Latin descriptions as hints to figure out what Pine you have!

1. ____________________________

2. ____________________________

One bundle or fascicle

Needle 5-7.6 cm long

3. ____________________________

4. ____________________________

5. ____________________________

Cone at the end of branch

Latin Name Common Name Meaning

Castanea chestnut old Latin name for the sweet chestnut

pumila Allegheny chinquapin

very small, low, small, dwarf

Fagus beech the Latin name, for the beech tree, from the edible seed of beech

grandifolia American beech with large leaves

sylvatica European beech wild, of woods or forests

Quercus oak the old Latin name, quercus, for an oak

alba white oak bright, dead-white

bicolor swamp oak two shades of red, bicolor-rosea

palustris pin oak of swampy ground

phellos willow oak cork

rubra red oak red

Descriptions from David Gledhill’s book, “The Names of Plants,” 4th Ed. Cambridge University Press, 2008.

Dichotomous Key activity: Use the dichotomous key to determine what five oak species are in each picture.

Dichotomous Key to the Oaks (Quercus) from the Fagaceae tree

A. Is your leaf edge indented/ lobed, or pointy ……………………………… Go to B

A. Is your leaf edge smooth with no lobes ………………………. Quercus phellos

B. Are the lobes on your leaf 5-7 smooth rounded lobes ………….. Quercus bicolor

B. Are the lobes on your leaf 7-9 smooth rounded lobes ………….. Quercus alba

B. Are the lobes on your leaf 5-7 toothed or wavy lobes …………… Quercus palustris

B. Are the lobes on your leaf 7-11 pointy, toothed lobes ……………. Quercus rubra

1. ___________________________________

2. ___________________________________ Photos Courtesy: Virginia Tech, Dept. of Forest

Resources and Environmental Conservation

7-9 lobes

5-7 lobes

3. ___________________________

4. ________________________________

5. _____________________________

Photos Courtesy: Virginia Tech, Dept. of Forest Resources and Environmental Conservation

more than 7 lobes