Bulbophyllum section Hirtula
The genus Bulbophyllum contains some of the most wonderful orchid species to be found in the world. Because
Bulbophyllum is such a large genus, with more than 2,000 species, its members are separated into sections of similar, or related, species.
Section Hirtula was established by the English botanist Henry Ridley in 1908, in his Materials for a Flora of the Malayan Peninsula, Singapore. The type of species for the section is the Malaysian species Bulb. hirtulum named by the same author. There are about 40 species in the section, of which four occur in the Philippines and these species are endemic, and do not occur in any other place on earth.
In 2002, Dr. Jaap Vermeulen, from the Netherlands, published a revision of the section in the Gardens’ Bulletin
Singapore. Species from this section can be distinguished by the distinct pseudobulbs, the swollen rachis of the
inflorescence (in Bulb. echinochilum), and the distinctly hairy edges of the labellum and the petals.
Bulbophyllum debrincatiae was only named in 2002. The first author (JC) went to Singapore in 2001, to check the proofs of his first book – The Orchids of the Philippines. JC also took the opportunity to visit Dr. Vermeulen at the Singapore Botanic Gardens to show him the
Bulbophyllum species which were to be included in the book. Upon seeing the picture of what JC had labelled as Bulb.
negrosianum, he immediately declared that this plant was an undescribed species, and the rest is history. An interesting feature of this plant is that the flowers start to open from the tip of the inflorescence, moving back towards the plant. This species is recorded from the mountains of central Luzon at elevations over 1,200 meters. It should be noted that Bulb. ebracteolatum and Bulb. saurocephalum, and its subspecies oncoglossum also have swollen inflorescences, but do not have the hairs around the edges of the petals or labellum. They belong in section Saurocephalum. Bulbophyllum echinochilum is a wonderfully bizarre species, with the swollen rachis of its inflorescence. In fact, this species was thought to be extinct, as no living specimens had been seen for more than 50 years. Then in the late 1990s a few plants arrived in Manila at the site of an orchid conference. At the time no one knew what this amazing species was! This species is now known to come from the mountains of central Luzon, and from Mindanao, at elevations over 1,200 meters. Bulbophyllum lasioglossum Robert Rolfe first described this species, but Professor Oakes Ames provided a more detailed description in 1905, in his
Studies in the Family Orchidaceae — Fascicle I. The specific epithet refers to the hairs on the labellum. H.N. Whitford collected the type specimens in the province of Bataan, on Luzon, in May 1904. Bulbophyllum lasioglossum is found in the provinces of Bataan, Laguna, and Nueva Ecija in Luzon. It grows as an epiphyte at elevations of about 1,000 meters above sea level. Bulbophyllum negrosianum Professor Oakes Ames named this species in 1912, in Elmer’s Leaflets of Philippine Botany. The specific epithet refers to the island of Negros where this plant was first collected.
Bulbophyllum negrosianum is endemic to the Philippines where it is found in the province of Nueva Vizcaya
in Luzon; and on the island of Negros in the Visayan Sea, growing epiphytically at elevations of about 1,400 meters above sea level. Of the species mentioned above,
Bulbophyllum echinochilum is the most commonly seen among traders. The other species remain mysterious, and one can only hope that this status is not due to over-collecting. As already explained, typical features are the hairy labella and petals, which would be almost constantly be in motion due to light breezes at higher elevations. This suggests, especially when observed in detailed macro pictures, that species in this section are mimicking insects, which most probably are their pollinators.