In order to understand how well the features of ginkgo leaves reflect the climate they grow in, we need to study leaves from trees growing in many different climates.
Ginkgos are the perfect plant for this. While their natural range is restricted to China, ginkgo trees can now be found all over the world, transported to new places by humans. Ginkgos also have a rich fossil record dating back to the Jurassic Period, meaning we can apply what we learn about reconstructing climates from today's ginkgos to the past hundred million years through beautifully preserved fossil leaves.
How can I help?
We're looking for citizen scientists to send us leaves from their communities!
What you will need
A Ginkgo tree that is at least 10 feet tall
A smartphone or computer + camera
A free account on iNaturalist
Materials to mail in your leaves - a large envelope, cardboard, newspaper and tape
Watch the video or follow the instructions below to join in with the research. A PDF of the complete instructions is also available for download here and a one page version is available here. There is also a flyer and a postcard if you would like to help share the project in your community.
If you are sending a sample from outside of the United States please follow this additional protocol to ensure the sample reaches us.
Questions? Email NMNH-Fossil-Atmospheres@si.edu
Fossil Atmospheres is funded by the National Science Foundation
In the app, for Android open the left hand menu (≡) or for iOS select 'more' (...), then select "Projects". Enter "fossil atmospheres" into the search feature to locate the project.
Select Fossil Atmospheres from the results that appear to view our project page.
Click the "JOIN" button under the leaf icon.
- Find a ginkgo tree that is at least 10 feet tall with green, unfurled leaves.
- Identify the sex of the tree.
- Collect 6+ leaves from a short shoot.
- Collect additional data on the tree.
- Not sure what a ginkgo tree looks like? Look for the distinctive leaves
- Make sure you aren't breaking any rules by collecting from the tree you've chosen! You should have permission to collect from a tree grown in a garden or on private property.
- We only need one collection from each tree and we are looking for geographic diversity, so if you are collecting with a group or want to send in more than one collection choose ginkgo trees that are at a distance from each other.
- Ginkgo trees are either male or female, males are often planted to avoid the stinky seed produced by female trees.
- The reproductive organs of the tree can be found alongside the leaves. While they are most prominent early on in the growing season (June/July), remnants of these organs should be visible on some of the branches or near the tree, if they have fallen.
- Male trees produce pollen cones. These form long bundles light yellow to green in color.
Pollen structures among leaves on a male ginkgo tree. (Modified from Agnieszka Kwiecień, Nova [CC BY-SA 4.0])
- Female trees are recognizable before pollination by long green stalks, ending in two round ovules. These develop into fleshy, green or yellow seeds that emit a strong odor later in the growing season.
Top: Ovules among leaves on a female ginkgo tree. (Modified from Marcin Kolasiński [CC BY-SA 4.0])
Bottom: Fruits produced after fertilization. (jy mit Kamera [Copyrighted free use])
- If you cannot determine the sex of the tree, please attempt to find another tree to collect from.
- Short shoots have a cluster of multiple leaves growing out from the end of a rough stub that is less than 1 inch long. Find a cluster with at least six leaves.
- If the leaves aren't clustered, don't collect them! Solitary leaves grow on long shoots, not short ones.
Close-up of a short shoot.
- Collect each leaf in the cluster by holding the stalk (i.e., petiole) and pulling down and away until the base of the stalk releases from the short shoot.
The stalk is important for analysis so make sure to collect each leaf intact with its stalk.
Put your leaves in a bag for temporary safekeeping.
- We highly recommend that you submit your observation immediately iNaturalist while still at the tree. However, if you are unable to submit right away on the app, we will still need you to do the following to properly submit at a later time:
- Photograph the entire tree
- Photograph the base of the tree
- Note the exact location of the tree (GPS coordinates or street address)
- If possible, note which side of the tree (north, east, south, or west) you collected from
- Without this information, we cannot use your samples!
- Login to iNaturalist online or in the mobile app.
- Begin a new observation.
- Add photos to the observation.
- Add a species identification to the observation.
- Check that the date, time, wild/cultivated and location fields are populated and accurate.
- Add your observation to the Fossil Atmospheres project.
- Fill in project-specific fields.
A. Login to iNaturalist online or in the mobile app
For iOS select the 'observe' camera icon in the bottom center. For Android open the left-hand menu (≡) and click the green "New Observation" option located at the bottom.
Click the green "Upload" button found in the upper right-hand corner of any page on iNaturalist.org.
If you have already taken photos of the ginkgo tree, select "Choose Image" or press the photo icon, and choose a photo of the tree from your phone's gallery. Otherwise, for iOS just take a photo, select "Take Photo" and take your first photo of the tree.
Once a photo has been uploaded, you will be taken to your new observation's "Details" page. Here, you can add additional photos by clicking the camera symbol in the upper left hand corner.
Upload photos of the tree you sampled using the "Choose Files" button or by dragging and dropping your files into the browser window.
You can add additional photos on the next page by clicking "Add" > "Photos or sounds" in the top menu or by dragging files into the browser window.
Merge the additional photo(s) with your new observation by dragging the photo into the same box.
Select the "What did you see?" field.
Type "ginkgo biloba" in the "Species Search" box.
Select the "Ginkgo biloba" entry, which features a photo of a ginkgo leaf, from the search results.
for Android you will then have to press the green "Select" button on the ginkgo details page to confirm your identification.
Search for "ginkgo biloba" in the "Species name" field under your uploaded photo and click on the matching "Ginkgo (Ginkgo biloba)" result, which features a photo of a ginkgo leaf.
The date, time, and location fields will self-populate based on your current time and location or metadata associated with the uploaded photo. You can manually update any field by pressing it.
Most Ginkgo have been planted so you should change the captive/cultivated field to 'yes'.
The date, time, and location fields under your uploaded photo will self-populate based on metadata associated with the uploaded photo. You can manually update any field by clicking it.
Most Ginkgo have been planted so you should change the captive/cultivated field to 'yes'.
At the bottom of the screen, for iOS press 'projects' and select Fossil Atmospheres. For Android press "Add to project(s)".
Check the box next to "Fossil Atmospheres".
If you do not see Fossil Atmospheres, scroll to the beginning of these instructions to find out how to join our project. If you have just joined the project you may have to shut the app and reopen it.
After checking the box, several project-specific fields will appear.
To add your observation to the Fossil Atmospheres project, you must first submit it to iNaturalist using the green button in the upper right-hand corner of the page.
You will then be taken to a page listing all of your submitted observations. View your new observation's detailed page by clicking on its photo or species name.
Add your observation to the Fossil Atmospheres project by searching for "fossil atmospheres" in the Projects section below the map of your observation location and select the matching result.
If you do not see Fossil Atmospheres, scroll to the beginning of these instructions to find out how to join our project.
After selecting the matching result, pop-up box will appear containing several project-specific fields.
- When you add your observation to the Fossil Atmospheres project, iNaturalist will ask for the additional information you collected in step 2 above:
- Approximate height of the tree: 10-30 ft or 30+ ft
- Sex of the tree: male or female
- Confirmation that two photos have been uploaded: no or yes
- Which side of the tree you collected from (optional): unknown, north, east, south, or west
After checking the fields are accurately filled in, for iOS just press back in the upper left corner. For Android select the check mark in the upper right-hand corner to confirm your answers.
Finally, submit the observation using 'Share' at the bottom of the screen for iOS, or for Android press the checkmark on the observation details page.
After checking the fields are accurately filled in, you must confirm each required field individually using the "Add" buttons on the right before you are able to join the project.
Once all required fields are confirmed, press the green "Add to Project" at the bottom of the pop up box.
- You can always access and make changes to observations you've submitted by visiting the "My Observations" view in the app, found by selecting 'Me' at the bottom of the screen in iOS, or for Android selecting your username in the left-hand menu (≡), or by viewing your list of observations on iNaturalist.org.
Items you will need
- Ginkgo leaves, intact and collected within the past 24 hours
- Envelope for shipping
- At least 2 pieces of cardboard of similar size, a little smaller than the size of the envelope
Making the cardboard sandwich
- If you are sending more than one set of leaves in the same shipment - for example, if you collected from multiple trees or were part of a group that made multiple collections, each collection must be in its own sandwich, so please repeat steps 4B through 4F for each set of six+ leaves, then put all the sandwiches in the same envelope.
- Each set should have its own unique observation already submitted to iNaturalist.
- Sandwich the collected leaves between two or more sheets of newspaper. Leaves should lie completely flat and not bent or overlapping.
- Place two sheets of rigid cardboard around the newspaper layers. In the end, your cardboard sandwich should look something like this:
- Wrap tape around all four edges of the cardboard sandwich tightly so that no items within it move during shipping.
- Write clearly in marker or pen your (1) iNaturalist username as well as the (2) date and (3) time of the observation you submitted in iNaturalist on the outside of each cardboard sandwich. We need to be able to link the leaves we receive to the data you submitted!
- Put all the cardboard sandwiches in an envelope or package, and before the end of August mail it to:
Smithsonian NMNH - Dept. of Paleobiology
10th and Constitution Ave NW
Washington, DC 20560
Congratulations! Thank you for partnering with us and contributing to ongoing scientific research.
If you or your organization would like advice on how to mail samples, shipping material, or pre-paid postage labels please send an email request to NMNH-Fossil-Atmospheres@si.edu