Sunday, June 20, 2021

[Botany • 2021] Paraboea khotamiae (Gesneriaceae) ດອກລະຄັງໂຄຕະມີ • A New Species of Paraboea and A New Species Record of Middletonia (Gesneriaceae) from A Limestone Karst of Central Laos


Paraboea khotamiae Phonep. & Souvann. 

in Phonepaseuth, Souvannakhoummane, ... et Yahara, 2021. 
ດອກລະຄັງໂຄຕະມີ  ||  DOI: 10.20531/tfb.2021.49.1.17 

ABSTRACT
A new species of Paraboea (Gesneriaceae), Paraboea khotamiae, from a limestone karst in central Laos, is described and illustrated. The species resembles Paraboea bintangensis, P. prazeri and P. robusta, but differs in leaf shape and floral features, especially corolla shape and size, the interior of the corolla tube, and capsule characters. In addition, we report the occurrence of Middletonia reticulata (Gesneriaceae) for the flora of Laos for the first time.

Keywords: Angiosperms, Flora of Laos, limestone flora, taxonomy


Paraboea khotamiae Phonep. & Souvann.:
A. Flower (front view); B. Flower (lateral view); C. Calyx lobes; D. Corolla opened out (adaxial side); E. Pistil; F. Stamens (front view); G. Stamens (lateral view); H. Capsule with persistent stigma.
 Materials from Phonepaseuth P010 (FOF). 
Line drawing by K. Souvannakhoummane.

Paraboea khotamiae Phonep. & Souvann.:
A. Habitat; B. Flowering plant; C. Leaves adaxial side (below) and abaxial side (above); D. Inflorescences; E. Flower (front view); F. Flower (back view); G. Lateral view of flower bud (left) and flower (right); H. Dissected flower showing corolla, stamens, pistil and calyx; J. Fruits.
Photos (A–H) from Phonepaseuth P010 (FOF) and (J) Phonepaseuth et al. P015 (FOF) by P. Phonepaseuth.


Paraboea khotamiae Phonep. & Souvann., sp. nov.

This species is most similar to Paraboea bintangensis B.L.Burtt from Peninsular Malaysia in its almost stemless habit, ovate or ovate-oblong leaves, axillary inflorescences and white flowers but differs in having 6–8 pairs of lateral veins anastomosing (vs ca 5 veins in P. bintangensis), 3 upper calyx lobes fused ½–¾ lobes length and 2 lower lobes free (vs 5calyx lobes free), and larger corolla 1.6–1.8 cm long, 1.6–2.4 cm across (vs ca 1 cm long, ca 1.5 cm across). Paraboea khotamiae is also similar to P. prazeri (B.L.Burtt) C.Puglisi from Myanmar in having long petiolate leaves, cymose inflorescence, 3 upper calyx lobes fused, and lingulate stigma, but differs in havinga broader stem 1–1.5 cm in diameter (vs 3–3.5 mm in diam. in P. prazeri), leaf blade ovate to ovate-oblong, glabrescent above (vs elliptic, pubescent with short hairs above), non-twisted capsules (vs twisted capsule). It also shares some similar characters with Paraboea robusta (B.L.Burtt) C.Puglisi from Thailand(Northern region) such as a white corolla, lingulate stigma, 3 upper calyx lobes fused, and cymose inflorescence, but differs in its shorter stem 0.8–1.2 cm long(vs at least 6 cm long in P. robusta), smaller ovate or ovate-oblong leaf blade 7–10 × 5–6 cm, glabrescent adaxially (vs narrowly elliptic-oblanceolate, 12–25 × 2–5.5 cm, densely pilose-pubescent adaxially). 

Type: Laos. Khammouan Province, Gnommalat District, in limestone karst, 30 Aug. 2020, Phonepaseuth, P. P010 (holotype FOF[FOF0005194!]; isotype HNL!).

Etymology.— The specific epithet “khotamiae” is coined in honour of Khotamy Sayyasone - ໂຄຕະມີ ໄຊຍະສອນ, who was the teacher of the first author in the field of biology and taxonomy. 
ດອກລະຄັງໂຄຕະມີ

Ecology.— Paraboea khotamiae grows on shaded limestone cliffs, associated with Begonia spp. (Begoniaceae), Amorphophallus spp. (Araceae) and some lithophytic ferns; ca 200 m elev.

 

 
Phongphayboun Phonepaseuth, Keooudone Souvannakhoummane, Shuichiro Tagane, Phetlasy Souladeth and Tetsukazu Yahara. 2021. A New Species of Paraboea and A New Species Record of Middletonia (Gesneriaceae) from A Limestone Karst of Central Laos. Thai Forest Bulletin (Botany). 49(1), 135-141. DOI: 10.20531/tfb.2021.49.1.17