Vegetative key to the families

Either: leaves whorled; or leaves opposite and interpetiolar stipules present (Fig. 29). Herbs and woody plants

Leaves whorled, or stipules as large as leaves giving the appearance of 6–8 whorled leaves

Shrubs or trees

Leaves less than 25 mm long

Leaves 3–6 mm long, terete, grooved underneath, crowded on the stems Ericaceae

Leaves 6–25 mm long