Alocasia scalprum A. Hay, Exotic Rainforest rare tropical plants

Alocasia scalprum A. Hay
Alocasia 'Samar Lance'

Sometimes confused with Alocasia heterophylla (C. Presl) Merr.

Alocasia scalprum was first introduced to us by avid Hawaiian plant collector Leland Miyano when he forwarded a photograph of his specimen and asked if I knew the correct species name. I did not. But with the help of botanists Peter Boyce and Lord Alistair Hay (Alistair identified the plant to science in 1999), via the International Aroid Society aroid discussion group Aroid l, Leland and I soon had an identification which turned out to be Alocasia (al-o-CAH-see-ah) scalprum. Alocasia species are known to be highly variable and not every leaf of every specimen will always appear the same.

However, there is a very similar but scientifically different species known as Alocasia heterophylla (C. Presl) Merr. A. Alocasia heterophylla, Photo Copyright 2007, Leland Miyano heterophylla was first described to science in 1908. Alistair explains the differences in the two species, Alocasia scalprum has very reduced posterior lobes to the leaf. Alocasia heterophylla also has rather distinctively conspicuous sub-marginal veins. The posterior lobes are found at the top of the blade whilr sub-marginal veins refers to the teretiary or minor leaf veins observed on the the leaf blade. Alocasia heterophylla has been collected in Quzon Province in the Philippines and you can see a photo of the blade on TROPICOS here: http://www.tropicos.org/name/210021

Once Leland and I began to research Alocasia scalprum Pete Boyce would forward a copy of Alistair's published description giving all the scientific details and background on the species. According to Alistair's published work, Alocasia scalprum is a "diminutive to small herb". With leaf blades similar in shape to a sharp dagger, the established blades are dark green with a tinge of blue while newly emerged foliage is a much lighter green as can be seen in our specimen photo. You should be aware that leaf coloration alone is not a characteristic indicating a different species.

Alocasia scalprum is composed with an exquisite leaf pattern, once mature the leaves are thick and measure 15 to 25cm in length (approximately 6 to 10 inches) by 2 to 5cm (3/4 to 2 inches) wide. However, upon examining the photo of Leland's specimen, Alistair noted there was some variance between Leland's plant and the norm. That would appear to indicate the species does have some natural variation in the blade shape and color. Variations such as color are both normal and acceptable, within aroids. They do not necessarily indicate a new species. You can find an article on this site which explains natural variation within species here: http://www.exoticrainforest.com/Natural%20variation%20within%20aroid%20and%20%20plant%20species.html

Alocasia scalprum was first introduced to aroid collectors as Alocasia cv. Samar Lance in the International Aroid Society journal Aroideana, volume 7 in 1984. An aroid, Alocasia scalprum produces a solitary inflorescence with a lanceolate (spear shaped) spathe measuring approximately 6cm (2.5 inches) in length. The spathe is green while the spadix is shorter than the spathe. The entire structure consists of a modiefed leaf that appears to be a hood known as spathe with a central column known as a spadix. Together these structures form the inflorescence. The inflorescence is commonly, but incorrectly, called a 'flower'. The actual flowers are minute, and are located on the spadix.

Aroid expert Julius Boos provided this explanation of the structure of an inflorescence, "In aroids, there are two types of infloresence. One with a bisexual spadix, where the male and female flowers occur in groups along the entire length of the spadix which is attended by a simple, leaf-like and sometimes attractively colored spathe. Examples of these species are the genera Anthurium, Monstera and Spathiphyllum. There other groups of aroid genera which produce a bisexual infloresence. In those, the male, female and sterile flowers are separated into distinct zones. The female flowers are the lowest on the spadix. In most cases the sterile flowers are above the female zone on the spadix with the male flowers at the top. In some species there is another sterile zone above the male zone. In this group the spathe is generally divided into two portions, the limb (upper blade) and a convolute lower tube or chamber which surrounds the zone of female flowers. Examples of this group are Alocasia, Amorphophallus and Philodendron."

Alocasia scalprum is endemic to (exclusively found in) the Philippines, but is said to be known only from Samar island. As a result of the limited habitat, A. scalprum is now quite rare in private collections. Alistair included this note in his published description of A. scalprum, "This species is apparently quite well known in cultivation in the Philippines, but not represented by any wild-collected herbarium material. Burnett (1984) notes that what is considered in the horticultural community to be one species is highly variable and he lists four selected varieties all said to have originated from the island of Samar. The only material I have seen in flower, which forms the holotype, seems exactly to match the cultivar known as `Samar Lance’. Although it seems probable that the other forms mentioned and illustrated in Burnett (loc. cit.) are conspecific with A. scalprum, this remains to be verified."

According to a collector/grower in the Philippines, Samar is the third largest island in the country but is extremely rural. It is presently infested with both the Philippines' military and rebels. As a result, study of local plant species is both hindered and difficult. It is suspected those inhospitable conditions may be the reason why there are many plant species in the region not classified and still unknown to the scientific world.

Our specimen was a gift from rare tropical grower Windy Aubrey who lives on the island of Oahu in Hawaii. We have it potted in fast draining soil containing extra peat, Perlite™, and orchid potting media. The Alocasia is growing very well in filtered sunlight. However, Alocasia species from this region of the globe do not do well when temperatures are allowed to drop into the mid 50 degree F. range or lower. Most will go dormant and some will simply not return the following year. As a result, we suggest you keep this species comfortably warm during the winter.

My thanks to Peter Boyce for verifying our specimen is Alocasia scalprum.

One personal note of explanation: Lord Hay legitimately posses his title as a result of family heritage, however he rarely uses the title with his name. Some in the aroid community have referred to Alistair, now retired, as Sir Hay. He recently informed me he is not a "Sir". Alistair resides several hours south of Sydney, Australia and currently grows Brugmansia. His website address is: http://www.MerooMeadowPerennials.com.au/

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