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Plagiostachys subsessiliflora Mazo. Plagiostachys longipetiolata Mazo. in Mazo, 2022. |
Abstract
Two new species of Plagiostachys from Zamboanga Peninsula, Philippines, are described and illustrated. Plagiostachys subsessiliflora Mazo and Plagiostachys longipetiolata Mazo, both have non-mucilaginous inflorescences. A distribution map, proposed conservation assessment, and an updated key to Philippine Plagiostachys species are provided.
Keyword: Alpinieae, IUCN, Plagiostachys escritorii, P. lourdesiae, P. strobilifera, taxonomy, Zamboanga
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| Plagiostachys subsessiliflora Mazo. A. Leaf attachment; B. Ligule; C. Bracteole; D. Calyx; E. Flower, calyx and bracteole removed; F. Longitudinal view of corolla tube showing epigynous glands, style, lateral staminodes and anther; G. Inflorescence, front view; H. Dorsal corolla lobe; I. Lateral corolla lobe; J. Inflorescence; K. Fruit. Drawn by J.P. Dalguntas. |
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| Plagiostachys subsessiliflora Mazo. A. Habit; B. Petiolate lamina showing inequilateral base; C. Ligule; D. Inflorescence, side view; E. Inflorescence, front view; F. Flower; G. Flower, calyx and bracteole removed; H. Longitudinal view of corolla tube showing epigynous glands, style, lateral staminodes and anther; I. Bracteole; J. Calyx; K. Corolla lobes; L. Dorsal corolla lobes; M. Labellum; N. Infructescence showing reddish to maroon immature fruits; O. Mature fruits. Photographs by K.R.F. Mazo. |
Plagiostachys subsessiliflora Mazo, sp. nov.
Diagnosis: Plagiostachys subsessiliflora is allied to P. escritorii Elmer and P. lourdesiae in having a gullet-type labellum. However, it significantly differs in having unequally 2(–3)-lobed ligules, lanceolate leaves, short pedicels, and trilobed anther crest.
Distribution and Habitat: Plagiostachys subsessiliflora occurs in semi-shaded of the municipality of Leon B. Postigo, Zamboanga del Norte, at 300–350 m elevation. It was observed growing on humus cover with fertile and moist soils near stream.
Etymology: The epithet subsessiliflora refers to the very short stalk of the flowers.
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| Plagiostachys longipetiolata Mazo. A. Leaf attachment; B. Inflorescence; C. Flower; D. Dorsal corolla lobe; E. Lateral corolla lobe; F. Calyx; G. Stamen, front view; H. Epigynous gland, style and stamen; I. Calyx; J. Dorsal corolla lobes; K. Corolla lobes; L. Stamen, side view. Drawn by J.P. Dalguntas. |
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| Plagiostachys longipetiolata Mazo. A. Habit; B. Terminal portion of the leafy shoot showing undulate leaves; C. Leaf adaxial view showing slender petioles; D. Ligule E. Inflorescence, inset front view of the flower; F. Flower; G. Flower, calyx and bracteole removed; H. Epigynous gland, style and stamen; I. Calyx; J. Dorsal corolla lobes; K. Corolla lobes; L. Labellum; M. Stamen, front and side view (preserved in ethanol). Photographs by K.R.F. Mazo. |
Plagiostachys longipetiolata Mazo, sp. nov.
Diagnosis: Plagiostachys longipetiolata is most similar to P. strobilifera var. strobilifera (Baker) Ridl. from Borneo, but differs significantly in having conspicuously petiolate lamina (6.8–8.0 cm long vs. sessile or subsessile), larger and emarginate ligules (4.5–6.0 mm vs. 3 mm, truncate), longer bracteoles (12–16 mm vs. 10 mm), and calyx tubes (13–15 mm vs. 10 mm), orbicular labellum (vs. ovate), and trilobed anther crest (vs. truncate).
Distribution and Habitat: Plagiostachys longipetiolata is only known from the type locality in the secondary lowland tropical rainforest of the municipality of Leon B. Postigo, Zamboanga del Norte, Mindanao. It was found along the river with shaded environment at 410 m elevation.
Etymology: The epithet longipetiolata refers to the long petioles of the leaf blades.
Kean Roe F. Mazo. 2022. Two New Species of Plagiostachys (Zingiberaceae) from Zamboanga Peninsula, Philippines. Taiwania. 67(2); 186-194. DOI: 10.6165/tai.2022.67.186
