Dendrobium and its Relatives, Part 13: Dendrobium section Oxyglossum

Members of the section Oxyglossum are some of the most colourful orchids that we know. They also have the great advantage of usually being small plants that have large flowers. Another advantage is that for many of the species, the flowers are long-lasting.

This section was created by Rudolf Schlechter, in 1905, in Nachträge zur Flora der deutschen Schutzgebiete in der Südsee: mit Ausschluss Samoa’s and der Karolinen (Addendums on the flora of the German protected areas in the South Seas: excluding Samoa and the Caroline Islands). The sectional name refers to the pointed labellum of many of the species. The type species for the section is Dendrobium cyanocentrum Schltr. Plants from this section are found mainly in New Guinea, but there are species in Sulawesi, the Philippines, Maluku and many of the islands of the Pacific Ocean.

DENDROBIUM BRASSII Tom Reeves and Paddy Woods named this species in 1989 in A Revision of Dendrobium Section Oxyglossum (Orchidaceae). The specific epithet honors Mr. L.J. Brass, a prolific plant collector in New Guinea. Plants can reach 8 1⁄2 inches (22 cm) in height. Inflorescences are two-flowered. Blooms are about 1 1⁄4 inches (3.2 cm) long. This species is only known from eastern New Guinea. It grows as an epiphyte at elevations between 4,900 and 7,200 feet (1,500–2,200 m).

[1] Den. brassii; grower: Cynthia Hill.

DENDROBIUM CUTHBERTSONII Ferdinand von Mueller named this species in 1888 in the Transactions & Proceedings of the Royal Society Victoria. The specific epithet honors Mr Walter Cuthbertson, a collector from the late 1800s, who was also the collector of the type specimens. Plants can reach a height of up to 3 inches (7.5 cm). An attractive feature of this species is the warty surface of the leaves. The flowers are up to 1 3⁄4 inches tall by 1 3⁄8 inches wide (4.5 cm tall by 3.5 cm wide). The color variation within this species is nothing short of stunning. This species is found in New Guinea, New Britain and New Ireland. It grows as an epiphyte at elevations of about 6,500 feet (2,000 m), on mossy tree trunks. It receives frequent rain and constant breezes.

[2] Den. cuthbertsonii ‘Anna’, grown by Ron Parson.

[3] Den. cuthbertsonii; grower: Marni Turkel.

DENDROBIUM CYANOCENTRUM Rudolf Schlechter named this species in 1905 in Nachträge zur Flora der deutschen Schutzgebiete in der Südsee: mit Ausschluss Samoa’s and der Karolinen (Addendums on the flora of the German protected areas in the South Seas, excluding Samoa and the Caroline Islands). The specific epithet refers to the dark blue coloration of the mentum. Plants can reach 3 inches (7.5.cm) in height. The flowers are up to about 3⁄4 inch (1.8 cm) wide. An interesting feature of the flowers is the reflexed sepals and petals. This species is endemic to New Guinea. It grows as an epiphyte at elevations between 130 and 5,200 feet (40–1,600 m).

[4] A white form of Den. cyanocentrum; grower: Marni Turkel.

[5] A blue form of Den. cyanocentrum; grower: Marni Turkel.

DENDROBIUM DEKOCKII Johannes J. Smith named this species in 1911 in the Bulletin du Jardin Botanique de Buitenzorg (Buitenzorg Botanical Garden Bulletin). The specific epithet honors Mr. A.C. de Kock who was a medical officer, from the Netherlands, who collected the plants in New Guinea in the early 1900s. Plants are up to 3 inches tall (8 cm). Flowers are up to 1 3⁄8 inches tall (3.5 cm). An interesting feature of this species is that the pedicel and ovary are the same color as the flowers. This species is endemic to New Guinea. It grows as an epiphyte at elevations between 7,500 and 12,500 feet (2,300–3,800 m).

[6] Den. dekockii, grown by Ron Parsons.

DENDROBIUM HELLWIGIANUM Fritz Kränzlin named this species in 1892 in Botanische Jahrbücher für Systematik, Pflanzengeschichte, und Pflanzengeographie. Leipzig (Botanical yearbooks for systematics, plant history, and plant geography. Leipzig). The specific epithet honors Franz Hellwig, collector of the type species. Plants can reach 9 1⁄2 inches (24 cm) in height. Inflorescences can have up to three blooms to about 1 1⁄4 inches (3.2 cm) long. This species is endemic to eastern New Guinea. It grows as an epiphyte at elevations between 4,600 and 8,850 feet (1,400–2,700 m).

[7] A blue form of Den. hellwigianum; grower: Hanging Gardens.

[8] A pink form of Den. hellwigianum; grower: Hanging Gardens.

DENDROBIUM LAEVIFOLIUM Otto Stapf named this species in 1924 in the Botanical Magazine. The specific epithet refers to the shiny leaves of this orchid. Plants are up to 7 inches (18 cm) tall. The flowers are about 1 3⁄4 inch (4.5 cm) in diameter. There is also a form of this species with cream-colored flowers. This is a widely spread species, which has been recorded from New Guinea, the Solomon Islands, the Louisades Archipelago, Vanuatu and the Santa Cruz Islands. It grows as an epiphyte at elevations between 1,100 and 7,000 feet (360–2,135 m).

[9] Den. laevifolium; grower: Marni Turkel. This species occurs in a wide range of color forms from deep, saturated violet to almost white.

DENDROBIUM MASARANGENSE Rudolf Schlechter named this species in 1911 in Repertorium Specierum Novarum Regni Vegetabilis. Beihefte (Repertory of New Species of the Vegetable Kingdom. Beihefte). The specific epithet refers to Mount Masarang in Sulawesi. Plants grow to about 3 inches (7.5 cm) tall. Flowers are up to 7⁄8inch (2.2 cm) long, and there can be up to four flowers on the inflorescence. This species is widespread and has been recorded from New Guinea, Bougainville Island, the Solomon Islands, New Britain, Sulawesi, the Philippines, Fiji, Vanuatu and New Caledonia. It grows as an epiphyte at elevations between 980 and 10,500 feet (300–3,250 m).

[10] A white form of Den. masarangense; grower: Steve Beckendorf.

[11] A blue form of Den. masarangense, grown and photographed by Dr. MiguelDavid De Leon.

DENDROBIUM NEBULARUM Rudolf Schlechter named this species, in 1928, in Repertorium Specierum Novarum Regni Vegetabilis. Beihefte (Repertory of New Species of the Vegetable Kingdom. Beihefte). The specific epithet possibly refers to the misty conditions in which this species grows. Plants reach 8 inches (20 cm) in height. Inflorescences can carry up to five flowers to about 1 1⁄4 inches (3.2 cm) long. This species is widely spread and has been found in Maluku and New Guinea. It grows as an epiphyte at elevations between 4,500 and 9,000 feet (1,400–2,800 m).

[12] Den. nebularum; grower: Hanging Gardens.

DENDROBIUM PARVULUM Robert Rolfe named this species in 1899 in Bulletin of Miscellaneous Information. Kew. The specific epithet refers to the very small size of the plant. There are three subspecies, but it appears only two are in cultivation.

subspecies minutumminutum Rudolf Schlechter first named this species as Dendrobium minutum in 1912. Paul Ormerod transferred it to subspecific status in 2003 in Oasis. The Journal. The subspecific epithet refers to the tiny stature of the plant. Plants are up to about 3⁄4 inch (2 cm) tall. Inflorescences carry up to three flowers, which are less than 1⁄2 inch (1.2 cm) high. This orchid is found in New Guinea, the Solomon Islands, Caroline Islands, Fiji and Vanuatu. It grows as an epiphyte at elevations between 1,900 and 8,700 feet (600–2,650 m).

[13] Den. parvulum subsp. minutum; grower: John Leathers.

subspecies huliorumhuliorum Tom Reeve and Paddy Woods named this subspecies in 1981 in The Orchadian. The subspecific epithet honors the Huli people of the region. Plants are up to about 13⁄4 inches (4.5 cm) tall. Inflorescences have up to three flowers, which are less than 3⁄8 inch (1 cm) high. This subspecies has whitish yellow flowers that do not widely open. This orchid is only found in eastern New Guinea. It grows as an epiphyte at elevations between 4,600 and 5,900 feet (1,400–1,800 m).

[14] Den. parvulum subsp. huliorum; grower: Marni Turkel.

DENDROBIUM PENTAPTERUM Rudolf Schlechter named this species in 1905 in Nachträge zur Flora der deutschen Schutzgebiete in der Südsee: mit Ausschluss Samoa’s and der Karolinen (Addendums on the flora of the German protected areas in the South Seas, excluding Samoa and the Caroline Islands). The specific epithet refers to the five wings of the ovary. The plants are up to 8 inches (20 cm) tall. Inflorescences bear up to three blooms to 1 3⁄8 inch (3.5cm) long. This species is endemic to the northeast of New Guinea. It grows as an epiphyte at elevations between 2,600 and 6,500 feet (800–2,000 m).

[15] Den. pentapterum; grower: Marni Turkel.

DENDROBIUM PETIOLATUM Rudolf Schlechter named this species in 1912 in Repertorium Specierum Novarum Regni Vegetabilis. Beihefte. (Repertory of New Species of the Vegetable Kingdom. Beihefte). The specific epithet refers to the petiole (leaf stalk) of this orchid. Plants can get to be 10 inches (25 cm) tall. Inflorescences can have up to 20 flowers to 3⁄4 inch (2 cm) long. This species has been recorded from eastern New Guinea, New Britain and the Solomon Islands. It grows as an epiphyte at elevations between 2,600 and 7,800 feet (800–2,400 m.)

[16] Den. petiolatum; grower: Marni Turkel.

DENDROBIUM PRASINUM John Lindley named this species in 1858 in the Journal of the Proceedings of the Linnean Society. Botany. London. The specific epithet possibly refers to the color of the flowers. Plants reach 7 inches (18 cm) in height. The inflorescence usually bears a single bloom to 11⁄2 inches (4 cm) in diameter. This species is endemic to the Fijian islands, in the Pacific Ocean. It grows as an epiphyte at elevations between 2,000 and 3,700 feet (600–1,150 m).

[17] Den. prasinum; grower: Hanging Gardens.

DENDROBIUM PTEROCARPUM Oakes Ames named this species in 1923 in Schedulae Orchidianae VI (Orchid Cards). The specific epithet refers to the winged seed capsules. Plants reach 6 inches (15 cm) tall. Inflorescences are up to 1 1⁄8 inches (3 cm) long and the flower to 3⁄4 inch (2 cm) long. This species is endemic to the southern Philippine island of Mindanao. It grows as an epiphyte at elevations of about 6,500 feet (2,000 m).

[18] Den. pterocarpum grown and photographed by MiguelDavid De Leon.

Dendrobium puniceum Henry Ridley named this species, in 1886 in the Journal of Botany, British and Foreign. The specific epithet means purple-colored. The plant illustrated here is one of its many color variations. Plants reach 3 inches (7.5 cm) in height. Inflorescences are two- flowered. Flowers are up to 3⁄4 inch (2 cm) wide. This species is found in New Guinea, New Britain and the Solomon Islands. It grows as an epiphyte at elevations of between 1,300 and 5,500 feet (400–1,700 m).

[19] Den. puniceum ‘Madison F.’ CBR/AOS; grower: Doug Kubo.

DENDROBIUM RUPESTRE Johannes J. Smith named this species in 1911 in Bulletin du Jardin Botanique de Buitenzorg (Buitenzorg Botanical Garden Bulletin). The specific epithet refers to growing on rocks, which this species occasionally does. Plants reach 2 3⁄8 inches (6 cm) tall. Inflorescences can have up to three flowers to 1 1⁄4 inches (3 cm) long. This species is endemic to New Guinea. It grows as an epiphyte and as a lithophtye at elevations between 4,900 and 10,100 feet (1,500–3,100 m).

[20] Den. rupestre; grower: Hanging Gardens.

DENDROBIUM SERANICUM Johannes J. Smith named this species in 1928 in Bulletin du Jardin Botanique de Buitenzorg (Buitenzorg Botanical Garden Bulletin). The specific epithet refers to the island of Seram (also called Seran or Serang). Plants grow to between an inch (2.5 cm) and 4 3⁄4 inches (12 cm) in height. Inflorescences can have up to four flowers about an inch (2.5 cm) long. This species is endemic to the island of Ceram, the largest island of the Maluku province, in the Indonesian archipelago. It grows epiphytically at elevations between 3,200 and 6,200 feet (1,000–1,900 m).

[21] Den. seranicum grown by Ron Parsons.

DENDROBIUM SUBACAULE Caspar Reinwardt first mentioned this species, but it was John Lindley who did the valid description in 1858 in the Journal of the Proceedings of the Linnean Society. Botany. The specific epithet possibly refers to the almost stemless inflorescences. Plants are up to 2 inches (5 cm) high. Inflorescences can have up to three flowers to 3⁄4 inch (2 cm) long. This species has been recorded from Maluku, New Guinea and the Solomon Islands. It grows as an epiphyte at elevations between 2,400 and 8,200 feet (750–2,500 m).

[22] Den. subacaule.

DENDROBIUM SUBULIFERUM Johannes J. Smith named this species in 1911 in Bulletin du Jardin Botanique de Buitenzorg (Buitenzorg Botanical Garden Bulletin). The specific epithet refers to the awl-shaped leaves of this species. Plants get to 4 inches (10 cm) in height. Inflorescences bear a single flower up to 3⁄4 inch (2 cm) long. This species is endemic to New Guinea. It grows as an epiphyte at elevations between 980 and 6,500 feet (300–2,000 m).

[23] Den. subuliferum; grower: Cynthia Hill.

DENDROBIUM SULPHUREUM Rudolf Schlechter named this species in 1912 in Repertorium Specierum Novarum Regni Vegetabilis. Beihefte. (Repertory of New Species of the Vegetable Kingdom. Beihefte). The specific epithet refers to the coloration of the flowers. Plants reach 5 inches (13 cm) in height. Inflorescences can have up to four flowers an inch (2.5 cm) long. This species is endemic to New Guinea. It grows at elevations between 2,600 and 11,800 feet (800–3,600 m).

[24] Den. sulphureum; grower: Marni Turkel.

DENDROBIUM VEXILLARIUS J.J. Smith named this species in 1910 in Bulletin de Départment de l’Agriculture aux Indies Néerlandaises. Buitenzorg. (Bulletin of the Department of Agriculture in the Netherlands Indies. Bogor.) The specific epithet means “flag carrying” and possibly refers to the bright colors of the flowers. There are six named color forms of this species. Plants can reach 16 inches (40 cm) in height but are usually much shorter. Inflorescences are short, bearing up to seven flowers, but usually only one or two blooms are present. Flowers are up to 1 3⁄4 inches (4 cm) in diameter. This species is found in New Guinea, Maluku and the Bismarck Archipelago. It grows as an epiphyte, and occasionally as a terrestrial at elevations between 4,000 and 11,500 feet (1,200–3,500 m).

[25–28] Den. vexillarius occurs in a very wide range of color forms: [25] grower: Hanging Gardens;[26] grower: Cynthia Hill; [27] grower: Marni Turkel; [28] grower: Golden Gate Orchids.

DENDROBIUM VIOLACEUM Fritz Kränzlin named this species in 1910 in Engler’s Das Pflanzenreich (The Plant Kingdom). The specific epithet refers to the coloration of the flowers. Plants reach up to a foot (30 cm) tall. The inflorescence can have up to four flowers to 1 3⁄4 inches (4.5 cm) long. This species is endemic to New Guinea. It grows as an epiphyte at elevations between 2,400 and 6,500 feet (750–2,000 m).

[29] A pink form of Den. violaceum grown and photographed by the author.

subspecies cyperifoliumcyperifolium Tom Reeve and Paddy Woods named this subspecies in 1989 in A Revision of Dendrobium Section Oxyglossum (Orchidaceae). The subspecific epithet refers to the foliage, which resembles that of a Cyperus (umbrella sedge) species. The distinguishing features of this subspecies are the pendulous growth habit and the very narrow leaf, which is less than 1⁄8 inch (2.5 mm) wide. The flowers are similar to the nominate species. This subspecies is only known from northern and western New Guinea. It grows as an epiphyte at elevations between 4,000 and 6,000 feet (1,200–1,850 m).

[30] A beautiful blue form of Den. violaceum; grower: Hanging Gardens.

[31] A light pink form of Den. violaceum; grower: Hanging Gardens.

DENDROBIUM YULIANIAE André Schuiteman and Peter O’Byrne named this species in 2016 in Orchideen Journal (Orchid Journal). The specific epithet honors Yuliani Puji Hastuti, wife of the first author. Plants reach about 3 1⁄2 inches (9 cm) tall. Inflorescences carry two flowers about 3⁄4 inch (2 cm) long. Known only from the Indonesian province of Maluku. Further habitat information is unknown, but one could assume that it grows as an epiphyte at midrange elevations.

[32] Den. yulianiae; grower: Cynthia Hill.