Amongst Rubiaceae, Cinchoneae with some outliers in the Old World have their headquarters at cooler levels.
The principal orders, arranged according to their numerical importance, are as follows: - Leguminosae,Rubiaceae, Orchidaceae, Compositae, Gramineae, Euphorbiaceae, Acanthaceae, Cyperaceae and Labiatae.
The flora includes mangroves, Rubiaceae, Sapotaceae and other forms requiring more than pure coralline material for their growth.
Labiate plants have decussate leaves, while Boragin aceae have alternate leaves, and Tiliaceae usua ally have distichous leaves; Rubiaceae have opposite leaves.
Of these, the orders most largely represented (together with their species) are: Leguminosae, 34 6; Filices, 318; Compositae, 281; Euphorbiaceae, 228; Orchideae, 170; Cyperaceae, 160; Rubiaceae, 1 47; Acanthaceae, 131; Gramineae, 130.