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| Ridsdalea alba K.Khamm., in Khammongkol, Chamchumroon, Poopath, et al., 2018. |
Abstract
Ridsdalea alba, a new species of Gardenieae from southern Thailand, is described and illustrated. It differs from R. sootepensis in having narrowly elliptic-oblong to obovate leaf blades that are glossy dark green above, thickly leathery in texture, with rounded to acute leaf apices, and revolute leaf margins. Moreover, the corolla tube is without purple speckles inside.
Keywords: Eudicots, Ridsdalea, Rothmannia, Gardenieae, Rubiaceae, new species, Thailand
Ridsdalea alba, a new species of Gardenieae from southern Thailand, is described and illustrated. It differs from R. sootepensis in having narrowly elliptic-oblong to obovate leaf blades that are glossy dark green above, thickly leathery in texture, with rounded to acute leaf apices, and revolute leaf margins. Moreover, the corolla tube is without purple speckles inside.
Keywords: Eudicots, Ridsdalea, Rothmannia, Gardenieae, Rubiaceae, new species, Thailand
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| Ridsdalea alba K. Khammongkol. A. Habit and habitat. B. Foliage showing trifoliate leaf clusters. C. Abaxial leaf surfaces. D. and E. Inflorescences. F. Salverform corolla. G. Fruit. H. Cross-section of a fruit and seeds. |
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| Ridsdalea alba K. Khammongkol. A. Flowering branch. B. Node with stipule. C. Flower, with salverform corolla. D. Flower bud. E. Flower with corolla tube slit open. F. Inferior ovary. G. Dorsal, ventral and lateral views of anther. H. Numerous ovules in 2 rows. I. Bracts. J. Fruiting branch. K. Transverse section of a fruit. L. Fruit. Drawn by Ms. Benjaluk Chuencharoen (all based on K. Khammongkol et al. KK151). |
Ridsdalea alba K. Khammongkol sp. nov.
This species is superficially similar to Ridsdalea sootepensis but differs in that its leaf blades are narrowly elliptic-oblong to obovate, glossy dark green above, thickly leathery, rounded to acute leaf apices, and revolute leaf margins. The corolla tube is without purple speckles inside. In contrast, R. sootepensis has leaf blades that are lanceolate to oblong-lanceolate, matt green above, leathery, acute to acuminate leaf apices, and plane margins. The corolla tube of R. sootepensis is with purple speckles inside.
Etymology:—In Latin, “alba” means white; the specific epithet refers to the white corolla.
Common name:—Phut Hom Sawate - พุดหอมเศวต (Thai).
Kwanjai Khammongkol, Voradol Chamchumroon, Manop Poopath, Sarunya Vajrodaya and Sarawood Sungkaew. 2018. Ridsdalea alba (Rubiaceae), A New Species from southern Thailand. Phytotaxa. 365(1); 96–100. DOI: 10.11646/phytotaxa.365.1.5