Appendix 5 Photographs

What to look out for when taking photos on the theme of willow (without catkins), with a view to determination.

- Habitus, or silhouette of the shrub or tree. This may also be a habitus in winter.

- Stem, to view the bark drawing.

- A tree or shrub recently pruned short: try to take picture of the perennial tuber.

- Thick twig, for the presence or absence of lenticels. Lenticels are cork pores = a warty opening filled with loose tissue through which air can enter. In S. caprea, they have a diamond shape.

- Terminal twig, in view of hairs and buds. A terminal twig is a shoot that provides longitudinal growth, on which the long shoot leaves grow.

- Other twigs, for hairiness, fasciation (= flattened twigs), buds and frosting.

- Longleaf and shortleaf top and bottom. In view of hairiness and nervature. Short-lot leaves are on short lateral branches without longitudinal growth.

- Support leaves or stipules.

- Striae on 2- or better 3-year-old twigs. To discover them, one needs to scratch away some bark. The membrane underneath can be scraped away with a 1-euro coin. In some species, one notices short or long striae on top of the bare wood. Sometimes they become visible only after a few days of drying.

- Any other curious detail. For example, stipule-like appendages in S. x mollissima var. undulata.

- A ruler or millimetre paper can give a lot of support.

- Of course, 1 photo can show several details.