1A. Leaves needle-like; stems woody……………………………………………………………………………. Plant 1
1B. Leaves with flattened blade, simple or lobed; stems herbaceous……………………………………………… 2
2A. Leaves deeply lobed; stamens numerous; petals purple……………………………………………… Plant 3
2B. Leaves unlobed; stamens 2-6; petals white or absent………………………………………………….. 3
3A. Flowers either staminate or pistillate on separate inflorescences; petals absent….. Plant 4
3B. Flowers perfect; petals 4, white………………………………………. Plant 2
Well done Andy,
just a note of caution, plant 4 is a willow, so it is woody too.