bearing essential oils. Perennial; without conspicuous aggregations of leaves.
Climbing, or self supporting (less often); mostly stem twiners. Mesophytic.
Leaves alternate; spiral; flat; ‘herbaceous’, or ‘herbaceous’ and membranous; petiolate; sheathing to non-sheathing; gland-dotted (pellucid punctate), or not gland-dotted; aromatic; simple.
Lamina entire (usually), or dissected; when dissected, palmatifid (trilobed); palmately veined, or pinnately veined; cross-venulate; often cordate.
Leaves exstipulate (but sometimes with the first 1–2 leaves of the suppressed axillary branches simulating stipules); leaf development not ‘graminaceous’.