Monday, December 17, 2018

[Botany • 2018] Dendrobium mizanii (Orchidaceae: Dendrobiinae) • A New Orchid Species of Dendrobium Sect. Calcarifera from Terengganu, Peninsular Malaysia

Dendrobium mizanii R.Go & E.E. Besi

in Besi, Nikong, Mustafa & Go, 2018. 
Photos by DigitalDome. 

Dendrobium mizanii, a new species to science belonging to Dendrobium Sect. Calcarifera was discovered in a summit region of a disturbed montane forest in Setiu, Terengganu, and named after His Majesty Sultan of Terengganu, Tuanku Mizan Zainal Abidin. A description, illustration, field and comparison with the closely related species D. crocatum from Peninsular Malaysia and D. doloissumbinii from Borneo are provided here.

Keywords: endangered, rescue, ex-situ, conservation, Dendrobium, new species, Monocots

Dendrobium mizanii R.Go et E.E. Besi, sp. nov.

 Type:— MALAYSIA. Terengganu: Setiu. ca. 1,300 m, ...

Diagnosis:—This species is very identical to Dendrobium crocatum Hook.f., a widely distributed species in Malaysia and Thailand, by having the plant almost similar morphologically with the stems slender, green-purplish, leaves lanceolate, flowers spreading with tip reflexed, and lip widely canaliculate but it clearly differs from the latter by having the lip 3- lobed, blade almost in the same length as the column (in natural position), midlobe widely rounded with apex decurved (curved downwards) and margin copiously undulate and crenate; mentum slightly bent downward; and roots distinctly thicker about 3 mm wide, white and covered with velamen. It shares similarities with D. doloissumbinii J.J. Wood on its stems up to 40 cm long, lip yellowish-green in with reddish-purple speckles and the midlobe apex wide, slightly decurved, but it differs by having the flower (less than 4 cm long) smaller, mentum (less than 2.5 cm long) shorter, and the lip distinctly 3-lobed with the apex copiously undulate. The D. doloissumbinii is also having blade much longer in length than the column (in natural position), similar to that observed in D. crocatum and other species in Sect. Calcarifera, including D. subflavidum Ridl. and D. lankaviense Ridl..  ...

FIGURE 1. Dendrobium mizanii, flower’s dissection.
A. Flower, top-lateral view showing the 3-lobed lip. B. Flower, lateral view showing decurved and copiously undulate lip apex. C. Flower, front view. D. Flower, closed-up lateral view. E. Flower, closed-up front view showing yellowish green with reddish purple speckles. F. Flowers at young stage during the pre-bloom period. G. Flowers at matured stage after the pre-bloom stage. H. Plant. I. Perianth. J. Lateral sepal. K. Petal. L. Dorsal sepal. M. Lip, flattened. N. Column apex showing stelids and rostellum. O. Anther-cap and pollinia. P. Column showing narrow foot.
Photos by DigitalDome.

Etymology:— This species is named after His Majesty Sultan of Terengganu, Tuanku Mizan Zainal Abidin. To commemorate His Majesty’s continuous dedications towards conservation ventures in Terengganu.

Distribution and Ecology:— The earliest specimen (holotype) was found in a summit of a montane forest in Setiu, Terengganu, at about 1,300 m above sea level, and growing terrestrially at the moist humus at the base of a tree. Then, the second specimen (isotype) was collected from the same area, but growing epiphytically on a medium-sized phorophyte tree.

  Edward Entalai Besi, Dome Nikong, Muskhazli Mustafa and Rusea Go. 2018. A New Orchid Species of Dendrobium Sect. Calcarifera from Terengganu, Peninsular Malaysia (Orchidaceae: Dendrobiinae). Phytotaxa. 383(2); 213–218. DOI: 10.11646/phytotaxa.383.2.7

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