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| Gastrodia gunatillekeorum Bandara, Priyankara & Kumar |
Abstract
Gastrodia gunatillekeorum, a new species in the family Orchidaceae, is described and illustrated from a tropical lowland rainforests of Sri Lanka. It is morphologically close to G. spatulata which is endemic to Indonesia owing to the white flower front with yellowish-orange colour on the inner wall of perianth tube and free part of perianth tube reflexed backwards. However, these two species can be very well differentiated on the basis of spathulate to linear petals which are shorter than sepals, fused only at the base and present inside the perianth tube; labellum elongate-elliptic and column broadest in the middle part in G. spatulata, whereas petals as long as sepals with apical 1/3rd part free (rest fused with sepals) and reflexed backwards, labellum rhomboid in shape, column broadest towards the apex in G. gunatillekeorum. Taxonomic account, line drawing, color photographs and conservation assessment are provided for the new species.
Keywords: Conservation, holomycoheterotrophic, potato orchid, Sinharaja MAB reserve, Neoclemensia, Monocots
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| FIGURE 1. Gastrodia gunatillekeorum Bandara, Priyankara & Kumar sp. nov. A. Plant (CB-201804-01-Holotype). B. Flowering plant. C. Front view of flower. D. Lateral view of flower. E. Dorsal view of flower. F. Flower bud with bract. G. Side view of lip and column. H. Ventral view of column. I. Dorsal view of lip. J. Dorsal view of column. K. Ventral view of lip. L. Capsule. M. Tuberous rhizome
(Scale bar = A-F 10 mm; G-K 5 mm; L,M 10 mm).
Photographs by Champika Bandara (A-L) and Anusha G. Atthanagoda (M).
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| FIGURE 2. Gastrodia gunatillekeorum Bandara, Priyankara & Kumar sp. nov. A. A flowering plant. B. Lateral view of flower. C. Dorsal view of flower. D. Front view of flower. E. Side view of lip and column. F. Ventral view of lip. G. Dorsal view of lip. H. Ventral view of column. I. Dorsal view of column. J. Dorsal view of anther cap. K. Ventral view of anther cap. L. Pollinia. M. Plant with fruits. N. Close up of fruit.
Illustrations by Champika Bandara and Pankaj Kumar.
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Gastrodia gunatillekeorum Bandara, Priyankara & Kumar, sp. nov.
Diagnosis: Gastrodia gunatillekeorum is close to Gastrodia spatulata, in having white coloured free frontal lobes of the perianth tube and yellow-orange colouration on the inner side of the perianth tube however, the former can be distinguished from latter in having perianth tube formed by fusion of both petals and sepals to almost 2/3rd of their length with 1/3rd of the apical lobe broadly ovate and slightly reflexed backwards (against perianth tube made mainly of sepals, with much shorter spathulate to linear petals fused to the sepals only at the base and upper part lying within the perianth tube in latter); labellum rhomboid shaped (against elongate-elliptic); column broadest towards the centre (against broadest towards the apex) and U-shaped stigma (against V-shaped).
Etymology: The species epithet is an eponym in the Latin genitive plural honouring the pioneer forest ecologists of Sri Lanka, Prof. Nimal Gunatilleke and Prof. Savitri Gunatilleke (University of Peradeniya) in appreciation of their dedication and decades of philanthropic work on the forest ecology and conservation in the region.
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| FIGURE 3. The typical habitat of Gastrodia gunatillekeorum; deep shaded terrain covered with thick leaf litter in Mesua-Shorea community, lowland tropical rain forest, Sinharaja MAB reserve, Sri Lanka.
Photograph by Champika Bandara.
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| FIGURE 4. Habit of A. & D. Thismia gardneriana B. & E. Burmannia championii C. & F. Aphyllorchis montana.
Photographs by Champika Bandara.
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Champika Bandara, Theja Priyankara, Anusha G. Atthanagoda, Tithira Lakkana, Sisira Ediriweera and Pankaj Kumar. 2020. Gastrodia gunatillekeorum (Gastrodieae, Epidendroideae, Orchidaceae), A New Species from A Lowland Rainforest of Sri Lanka. Phytotaxa. 436(1); 55–62. DOI: 10.11646/phytotaxa.436.1.5
