Q.Distinguish between simple and compound leaves, with reference to venation.

A simple leaf has a single, undivided lamina (blade) -- even if its margin is deeply incised, the incisions never reach all the way down to the midrib, and it bears just one axillary bud at its base, at the junction of the petiole and the stem. A compound leaf, in contrast, has its lamina divided all the way to the midrib (or to the petiole) into several completely separate leaflets, and crucially only the whole compound leaf has an axillary bud in its axil -- individual leaflets never bear their own axillary buds, which is the definitive test for telling a leaflet apart from a small simple leaf. The venation pattern (reticulate in most dicots, parallel in most monocots) runs through each leaflet of a compound leaf just as it wou …

Use the axillary-bud test as the decisive criterion (present at the leaflet or only at the base of the whole leaf), and note that venation type …

• Assuming a leaflet of a compound leaf is itself a small simple leaf, forgetting the axillary-bud test that distinguishes them. …