The surface of the summit (the highest point is variously stated at 3549, 35 82 and 3850 ft.) is broken into small valleys and hills, and is covered with luxuriant vegetation, its flora including the superb orchid Disa grandiflora and the well-known silver tree.
Among these are species of Willughbeia and Leuconotis, from which much of the rubber exported from Borneo is derived; Parameria glandulifera, common in Siam and Borneo, and Urceola esculenta and Cryptostegia grandiflora, both common in Burma.
C. auriculata, 2 to 3 ft., has yellow and brown flowers in July and August; C. lanceolata, 2 to 3 ft., bright yellow, in August; next to the biennial C. grandiflora it is the best garden plant.
The prickly poppy (Argemone grandiflora) is a fine Mexican perennial with large white flowers.
This is also seen in a transverse section of the calyx of Magnolia grandiflora, where each of the three leaves embraces that within it.