DENDROCHILUM | Herbarium Digital Library


» Herbarium Digital Library

DENDROCHILUM

Category: Plants and Orchids
Date Posted: 2006-10-16

THIS IS ONE OF THE LARGEST OF PHILIPPINE ORCHID GENERA and includes approximately seventy species. The only other groups which are larger are Dendrobium and Bulbophyllum with approximately eighty-four and eighty-six species, respectively. Although a large genus, only a few Dendrochilum have become prominent as horticultural plants, because the individual flowers seldom exceed a fraction of an inch in diameter. Nevertheless, the genus demands a general appraisal for it is one of the major Philippine Orchid genera.

Dendrochilum was established by the botanist Blume in 1840 and, as it is now understood, is a complex group which comprises three sections, EUDENDROCHILUM, ACORIDIUM, and PLATYCLINIS, In the past, various authorities have considered these sections as separate genera; however, Professor Oakes Ames, in Fascicle II, Orchidaceae, 1908, has grouped them all under the one genus, Dendrochilum. Some authorities have also been of the opinion that the sections of this group were more closely related to the genus Dendrobium and Bulbophyllum, but as it is presently understood, the group is thought to have a closer alliance to the genera Pholidota and Coelogyne.

There are approximately 150 species of this genus distributed throughout southeast Asia, and about sixty-nine of these are indigenous to the Philippines. The generic name is derived from the words dendron or "tree" and chilum meaning "lip." Generally, the plants of the genus have short pseudobulbs, which grow in clumps and are terminated by a single leaf. The florescence is long, pendulous, and in many species has a sharp bend. The flowers are numerous and alternately arranged along the threadlike flower stem.

D. filiforme is a medium-sized Dendrochilum with a pseudobulb about one to two inches long and less than one quarter in width, with a terminal leaf five to six inches long and one-half an inch wide. The inflorescence develops from the base of the new growth and is arching, about ten to twelve inches long. The first half of the flower stem is generally upright, and 'there is a distinct sharp bend at the middle and the flowers are formed on the drooping portion. Each flower is about one-quarter of an inch across and light yellow in color with a spicy fragrance. The minute floral parts are extremely delicate and fanciful and the specific name filiforme is derived from the Greek words meaning threadlike in reference, to the ~ thin flower stalk. D. fili f orme has approximately thirty to one hundred flowers on a stem and is in flower during July. The plant has been collected from the low-altitude forests along the mountainous east coast of Luzon.

D. Cobbianum (Platyclinis Cobbianum) is a mountain species that is common in the forests from four thousand to seven thousand feet elevation and is frequently seen growing as a semiterrestrial on the rocks and cliffs north of Baguio, Mountain Province. The pseudo-bulbs of this species are clumped about four inches long and half an inch thick. The petiole or leaf stalk is about two inches long and the leaf is coarser than most of the other species of this group. The flower stalk, which is twelve to fifteen inches long, is erect up to the point where the flowers are attached and from this point the rachis is pendulous. The flowers have a peculiar lip which minutely resembles a dancing girl with a.crown. Each flower is about one-half inch across; creamy white with a bright orange labellum. This species was discovered by William Boxall in 1879 and described by H. G. Reichenbach in 1880, from a plant grown by Walter Cobb for whom it was probably named. Its flowering season is from June through August.

The Dendrochilum are attractive plants and most have a spicy fragrance. It is unfortunate that the flowers are so small that they cannot be fully appreciated and their intimate details observed unless seen through a magnifying glass. However, the large number of flowers compensates somewhat for what they lack in individual size.