Alocasia sinuata in the wild

A popular subject in horticulture, Alocasia sinuata is a small-growing Philippine endemic with bullate, thickly coriaceous, shiny leaves. The plants start out green then mature into a deeper green with almost metallic gray patina and with dark green sunken veins, resulting in a memorable foliage display of pure bliss. The species was described by Nicholas Edward Brown in 1885 from a cultivated specimen from Kew which was given by William Bull. The original collector of this plant is unknown. In the type sheet, Brown noted that it was collected in the 'Malay Archipelago' which Brown himself corrected to 'Philippines'. A photo of the holotype can be viewed here:

http://apps.kew.org/herbcat/getImage.do?imageBarcode=K000291398

What is notable in the type specimen is the very deep sinus with rather distant posterior lobes. However, as noted by George Yao, an ardent student of Araceae in the Philippines, posterior lobing and sinus depth is variable in Alocasia anyway. Alocasia sinuata was so-named for the sinuate (wavy) margins, but as the holotype and many cultivated plants show, the waviness of the blade margins are poorly expressed. Below is a photo of a Ramos & Pascasio collection from Surigao. Note how one leaf is decidedly peltate:

http://apps.kew.org/herbcat/getImage.do?imageBarcode=K000400157

The photos presented here were taken from Samar, and the plants grow in shade with their roots attached directly on limestone facing an estuary at an elevation of about 10 m asl. Leaf litter and thin mats of mosses partially cover the base of the plants including the petioles. The roots are kept moist by the drippings (Samar is known for its extensive cave systems and this habitat is one of those) but the almost fully vertical manner in which these plants grow ensures that waterlogging is never an issue. Air circulation is constant which brings cooling breeze 24/7.

To give you an idea of the prevailing conditions, here is a photo of a tree limb occupied by epiphytes and mosses:

A young plant of A. sinuata with typical green leaf coloration:

Subadult specimen with leaves already tending toward gray-green:

Mature plants rooting on extensive forest debris. This photo is manipulated to better show the plants; this spot, in reality, is much shadier than illustrated here:

Most of the plants shown in this rather bad photo have non-peltate leaves.

Alocasia sinuata is also known from Palawan, Leyte, and Mindanao. However, the Palawan specimen (cultivated at The Missouri Botanical Garden and originally collected by Tom Croat) has a suite of characters said to not fully fit the species, such as in the much attenuated sterile interstice and secondary venation not forming subsidiary veins, though otherwise matching A. sinuata (Hay 1999). Finding these plants in Palawan and studying the population as a whole is needed to elucidate their exact identity. Some plants in cultivation, I should add, appear to have watered-down A. sinuata traits and may be hybrids.