Protocol for Collecting Baobab Leaves:

Use zip-loc bags containing silca gel. We use a fine, granular, colourless gel (34-12 mesh) for the majority of drierite, with a few large indicator crystals (blue) that turn pink if the silica gel has been depleted.

Jack can send some bags to you, if needed (address below).

1. Make sure that knife, razor blade or scissors used to cut off the leaf-stem are carefully cleaned before use. Soapy water is best. If you use alcohol to clean the instrument, rinse it off finally with water. If you can tear off the leaf-stem, that would be even better.

Same for your hands. Use a new pair of gloves each time if it is not possible to thoroughly clean your hands between specimens.

Remember the CSI shows on TV! The DNA methods used in this study are very sensitive. Contamination of one specimen by another could ruin the study.

(You can bypass all this hassle with gloves and a clean cutter by using the plastic bag containing the drierite as a kind of glove. Shove the leaves into the bag using the stem or branch attached to the leaves, and then tear off the leaves using your fingers to hold them from outside the plastic bag, with a layer of plastic separating fingers from leaf. We used this technique recently to collect leaves in a chopper in the Kimberley where it was too inconvenient and time-consuming to fuss with gloves and cutting implements).

2. Note the location of the tree on the label of the sample bag, along with any notes about the tree or the locality and the name of the collector.

3. Take a single leaf, choosing an emerging fresh leaf if possible. If you have multiple leaves on a stem, tear them off and choose a maximum of 2 to put in the bag. Before putting in the bag, tear the leaf into roughly 2 cm X 2 cm pieces.

If the stem you cut off looks to yield more than ~5 g of leaf (about 8 leaves), split it into separate duplicate samples in separate bags. Be sure to label the extra bag(s).

4. Seal the leaf(s) in the sample bag.

5. Shake the bag so that the silica gel is distributed over the leaf(s). There are scattered indicator crystals among the silica powder. These should be blue. If there is any pink colour, water has entered the bag and it should not be used until the gel is regenerated.

To regenerate the silica gel, empty it into a microwaveable container such as a bowl and microwave for 10 minutes. The contents of up to 5 bags can be regenerated together in this way. Note that the bagπs contents are completely harmless, unlike some collecting materials, and so do not pose any risk in your kitchen.

6. Keep the sample bags cool, out of the sun. Put them into sealed plastic containers when you can. These can be stored later in the fridge, but DO NOT FREEZE unless the leaves have dried to the point where they are quite brittle..

7. Post the container with the bags back to Jack using the address label provided.

Notes: The powder in the bag is silica gel, a drying agent. Do not allow any moisture to come in contact with the specimen or the bag. If the Wet comes in early this year, try to keep everything dry! Fresh paper towel would be OK to wipe off a wet leaf. Pink colour of the larger crystals indicates wetting (they are blue when dry). Pink drierite can be regenerated in the microwave, as described above.

Any questions to Jack at 0488 431941 ; j.pettigrew@uq.edu.au