Teepically a leaf is a thin, flattened organ borne abuin the grund an specialized for photosynthesis, but mony types o leafs is adaptit in weys naur unrecognisable in thae terms: some arenae flat (for insaumple, mony succulent leafs an conifers), some arenae abuin the grund (like bulb scales), an some dinna hae major photosynthetic function (consider for insaumple cataphylls, spines, an cotyledons).
Conversely, mony structurs o non-vascular plants, or even o some lichens, that isnae plants at aw (in the sense o bein members o the kinrick Plantae), dae leuk an function a fair bit lik leafs. Furthermair, several structurs foond in vascular plants leuk lik leafs but arenae actually leafs; thay differ frae leafs in thair structurs an origins. Insaumples include phyllodes, cladodes, an phylloclades.
- Haupt, Arthur Wing, Plant morphology. Publisher: McGraw-Hill 1953. Downloable from http://www.archive.org/details/plantmorphology00haup
- Mauseth, James D. Botany: An Introduction to Plant Biology. Publisher: Jones & Bartlett, 2008 ISBN 978-0763753450