Glands on the leaf, petiole and stipule.

Many plants have glands or gland-like structures in various positions on the leaves, petioles or stipules. On the leaf blade they may be visible on the upper or lower surface, or both. In some cases they are called extra-floral nectaries. Use a hand lens or microscope to look for the glands as they are not always easy to see. Sometimes it is difficult to distinguish glands and gland-like structures from marks made by insect or fungal damage, especially in dried material where colour, texture and shape may be lost.

Neotropical Euphorbiaceae and related families (Peraceae, Phyllanthaceae, Picrodendraceae, Putranjivaceae). In this group the glands/gland-like structures are often distributed at or near the base of the leaf blade (i.e. in about the lower 1/5th of the leaf), more or less bordering the leaf margin, or on the leaf teeth, or in some combination of these three patterns. Less often they are distributed more centrally along the length of the leaf, or (rarely) are scattered sparsely to densely over the entire leaf blade. Glands/gland-like structures occur in a variety of shapes and sizes, some less than 1 mm across. In the interactive Key the presence of glandular hairs is treated as a separate feature (under indumentum type). Sometimes peltate hairs (disc-like hairs) can be misinterpreted as small glands. In the Key we are aware of a number of errors in data interpretation and scoring, and are working to correct these as soon as possible.

Examples from neotropical taxa.

á Aleurites (leaf base) á Aparisthmium (leaf base) á Tetrochidium (petiole apex)

á Ricinus (petiole apex) á Discocarpus (petiole apex) á Brasiliocroton (petiole apex)

á Croton (petiole apex) á Alchornea (petiole apex) á Concevebia (leaf base)

á Alchorneopsis (leaf base) á Bernardia (leaf base) á Bermardia (leaf base)

á Maprounea (leaf base) á Didymocistus (leaf underside) á Romanoa (leaf)

á Ditta (leaf margin) á Colliguaja (leaf margin) á Gymnanthes

á Vaupesia (petiole apex)