Research Article |
Corresponding author: Richard M.K. Saunders ( saunders@hku.hk ) Academic editor: Thomas L.P. Couvreur
© 2018 Junhao Chen, Piya Chalermglin, Richard M.K. Saunders.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Chen J, Chalermglin P, Saunders RMK (2018) Two new species and two new records of Artabotrys (Annonaceae) from Thailand. PhytoKeys 95: 71-81. https://doi.org/10.3897/phytokeys.95.23434
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Two new species of Artabotrys are described from Thailand. Artabotrys tanaosriensis J.Chen, Chalermglin & R.M.K.Saunders, sp. nov., is similar to A. oblanceolatus Craib but differs in its symmetrical, cuneate or decurrent leaf base, externally distinct outer petal blades and claws, deltoid and undulate outer petal blades, rhomboid and undulate inner petal blades and shorter, subsessile and slightly beaked monocarps. Artabotrys spathulatus J.Chen, Chalermglin & R.M.K.Saunders, sp. nov., is most similar to A. tanaosriensis but differs in having flat outer petal blades, broadly rhomboid outer petal claws, broadly spathulate and strongly concave inner petal blades and strongly beaked monocarps. Two new records for the Flora of Thailand are furthermore reported here: A. punctulatus C.Y.Wu ex S.H.Yuan and A. byrsophyllus I.M.Turner & Utteridge, which were previously confused with A. aeneus Ast and A. grandifolius King, respectively. A key to Artabotrys species indigenous to Thailand is provided here.
Annonaceae , Artabotrys , new records, new species, Thailand
Artabotrys R.Br. is one of the largest palaeotropical genera in the Annonaceae, with ca. 105 species (
The underlying floral Bauplan of Artabotrys species is rather uniform, with the exception of two African species, viz. A. thomsonii Oliv. (
Although Artabotrys is comparatively well-studied in Thailand, many names have been misapplied and several taxonomic and nomenclatural misunderstandings persist.
Examination of herbarium specimens and fieldwork in Thailand has revealed two new Artabotrys species, which are formally described here. In addition, two new records for Thailand are reported and past taxonomic errors rectified. A total of 15 species are recognised (excluding the aforementioned problematic taxa) and a key to the native species of Artabotrys in Thailand is provided.
The material studied comprises herbarium specimens of Artabotrys species from Thailand and neighbouring regions from the following herbaria: A, E, KUFF, KUN, L, NY, QBG, SING and US; high-resolution digital images of specimens (especially types) from JSTOR Global Plants (https://plants.jstor.org/) and other virtual herbarium websites; as well as fresh material collected during fieldwork in Thailand. Species delimitation was based on discontinuities (gaps) in morphological variation. The morphological gap is an indirect assessment of the underlying reproductive isolation because the lack of gene flow prevents two lineages from homogenising (
Similar to Artabotrys oblanceolatus Craib except with cuneate or decurrent (vs. rounded) leaf base, symmetrical (vs. asymmetrical) leaf base, externally distinct outer petal blades and claws, deltoid and undulate (vs. ovate and flat) outer petal blades, rhomboid and undulate (vs. ovate and flat) inner petal blades, shorter monocarps (1.5–2 cm vs. 2–2.5 cm), slightly beaked (vs. sharply beaked) monocarps and monocarps with shorter stipes (ca. 2 mm vs. ca. 4 mm).
THAILAND: Phetchaburi Province, Kaeng Krachan National Park, Phanoen Thung Ranger Station, 1000 m elev., 25 Aug 2004, I.C. Nielsen 1911 (holotype: L! [barcode L 3729228]; isotype: AAU, n.v.; SING! [barcode SING 0115634]).
Climbers, to 20 m in height. Twigs drying grey-brown, glabrous to sparsely hairy. Leaf laminas 9.5–15.5 cm long, 2.3–4.0 cm wide, oblong-elliptic, apex acuminate, base cuneate or decurrent, chartaceous, glabrous both ab- and adaxially; midrib glabrous to sparsely hairy abaxially, glabrous adaxially, prominent and raised on both surfaces; secondary veins 8–12 pairs per leaf, visible on both surfaces; tertiary venation reticulate, visible on both surfaces; petioles 2–5 mm long, ca. 1 mm in diameter, glabrous to sparsely hairy. Inflorescence hooks recurved, laterally compressed, with 1–3 flowers; flowering pedicels 7–9 mm long, ca. 1 mm in diameter, glabrous. Sepals ca. 4 mm long, 4–6 mm wide, triangular, subglabrous both ab- and adaxially, venation indistinct. Outer petals with externally distinct blades and claws; blades 10–12 mm long, 7–8 mm wide, deltoid, undulate, sparsely hairy both ab- and adaxially; claws ca. 4 mm long, 6–8 mm wide, broadly ovate, densely hairy abaxially, subglabrous adaxially. Inner petals with externally distinct blades and claws; blades 7–10 mm long, 4–5 mm wide, rhomboid, undulate, sparsely hairy both ab- and adaxially; claws ca. 6 mm long, ca. 4 mm wide, rhomboid, densely hairy abaxially, glabrous adaxially. Stamens ca. 90 per flower, ca. 1 mm long, ca. 1 mm wide; apex of connectives truncate. Carpels 24–30 per flower, ca. 1 mm long, ca. 1 mm wide; ovaries ovoid; stigmas ellipsoid, extending centrifugally. Fruiting pedicels 10–11 mm long, ca. 2 mm wide, glabrous. Monocarps 8–30 per fruit, 15–20 mm long, 9–13 mm wide, ellipsoid, glabrous, slightly beaked (beak less than 1 mm long), drying with longitudinal ridges, subsessile or with stipes up to ca. 2 mm long. Seeds 2 per monocarp, plano-convex, ca. 16 mm long, ca. 8 mm wide.
Flowering specimens collected in February and August; fruiting specimens collected in October.
So far only known from Thailand (Fig.
The specific epithet alludes to “Tanao Sri”, the Thai name of the Bilauktaung subrange of the Tenasserim Range where this species occurs.
Karawek Tanao Sri.
Thailand: Prachuap Khiri Khan Province, Hua Hin District, Huai Sat Yai, Pa La-U Village, 17 Oct 2016, P. Chalermglin 591017 (BKF, HKU, L, QBG); Phetchaburi Province, Kaeng Krachan District, Huai Mae Phriang Village, 14 Feb 2015, P. Chalermglin 580214 (BKF, HKU, L, QBG).
Similar to Artabotrys tanaosriensis J.Chen, Chalermglin & R.M.K.Saunders except with flat (vs. undulate) outer petal blades, broadly rhomboid (vs. broadly ovate) outer petal claws, broadly spathulate and strongly concave (vs. rhomboid and undulate) inner petal blades and strongly beaked monocarps.
Artabotrys spathulatus. A Flower with flat outer petal blades and broadly spathulate and strongly concave inner petal blades B Inflorescence with hooked peduncle and flower with externally distinct inner petal claw and blade C Fruit with distinctly beaked monocarps D Flower with externally distinct outer petal blade and claw E Leaves and habit (Photos: P. Chalermglin).
THAILAND: Krabi Province, Mueang Krabi District, Phruksa Sawan limestone hill, 100 m elev., 15 Mar 2015, P. Chalermglin 580315 (holotype: BKF!; isotypes: L!, QBG!).
Climbers, to 20 m in height. Twigs drying brown, glabrous to sparsely hairy. Leaf laminas 9.6–18.1 cm long, 3–4.5 cm wide, oblong-elliptic, apex acuminate, base cuneate or decurrent, chartaceous, subglabrous both ab- and adaxially; midrib glabrous to sparsely hairy abaxially, glabrous adaxially, prominent and raised on both surfaces; secondary veins 6–14 pairs per leaf, visible on both surfaces; tertiary venation reticulate, visible on both surfaces; petioles 2–6 mm long, ca. 1 mm in diameter, glabrous to sparsely hairy. Inflorescence hooks recurved, laterally compressed, with 1 or 2 flowers; flowering pedicels ca. 10 mm long, ca. 1 mm in diameter, subglabrous. Sepals 4–5 mm long and wide, triangular, subglabrous both ab- and adaxially, venation indistinct. Outer petals with externally distinct blades and claws; blades 8–10 mm long, 7–8 mm wide, deltoid, flat, sparsely hairy both ab- and adaxially; claws ca. 5 mm long and wide, broadly rhomboid, densely hairy abaxially, glabrous adaxially. Inner petals with externally distinct blades and claws; blades 6–7 mm long, 4–5 mm wide, broadly spathulate, strongly concave, sparsely hairy both ab- and adaxially; claws ca. 5 mm long, ca. 3 mm wide, narrowly rhomboid, densely hairy abaxially, glabrous adaxially. Stamens numerous per flower, ca. 1 mm long, ca. 1 mm wide; apex of connectives truncate. Carpels ca. 30 per flower, ca. 1 mm long, ca. 1 mm wide; ovaries ovoid; stigmas ellipsoid, extending centrifugally. Fruiting pedicels unknown. Monocarps (in fresh material) up to 30 per fruit, 19–26 mm long, 14–18 mm wide, obovoid, strongly beaked (beak ca. 2 mm long), sessile. Seeds 2 per monocarp, plano-convex, 12–14 mm long, 9–11 mm wide.
Flowering and fruiting specimens collected in March.
So far only known from Thailand (Fig.
The specific epithet reflects the morphology of the inner petals.
Karawek Phruksa Sawan.
The fruit and seeds are only known from fresh material and have not been preserved due to fungal infection.
The distinction between A. spathulatus and A. tanaosriensis is corroborated by unpublished phylogenetic analysis of combined chloroplast (matK, ndhF, psbA-trnH, trnL-F) and nuclear (AP3, carboxymethylenebutenolidase, GI, HMGS, LFY, mag1, ncpGS, NIA, PhyA, RPB2) DNA sequence data, which retrieved A. spathulatus as sister to A. uniflorus, with A. tanaosriensis sister to A. suaveolens (J. Chen et al. unpublished data).
Artabotrys byrsophyllus I.M.Turner & Utteridge, Nordic J. Bot. 33: 562 (2015). – TYPE: Malaysia, Peninsular Malaysia, Kelantan, Ulu Sungei Aring near Kuala Tapah, 21 Sep 1967, P.F. Cockburn FRI 7151 (holotype: K! [2 sheets, barcodes K 000607815, K 000607816], isotype: KEP, n.v.).
Karawek Bai Yai.
Thailand: Narathiwat Province, Kaluwotai, Khao Chana, 21 Sep 1985, C. Niyomdham et al. 1065 (AAU, BKF); Waeng district, T. Insura 77 (KUFF); idem, T. Insura 78 (KUFF); idem, T. Insura 90 (KUFF); idem, A. F. G. Kerr 14474 (BM); idem, S. Phusomsaeng 389 (BKF).
The name A. grandifolius is misapplied by
Artabotrys punctulatus C.Y.Wu ex S.H.Yuan, Acta Bot. Yunnan. 4: 260 (1982). – TYPE: China, Yunnan, Jinghong, 1015 m, 9 Apr 1957, Exped. Biol. Sino-Ross. ad prov. Yunnan 7654 (holotype: KUN! [barcode KUN 0045889]; isotypes: IBSC, n.v., PE! [barcode PE 00934500]).
Southern China (Yunnan) and Thailand (Khao Yai National Park and Phu Kradueng National Park), in lower montane forests, 1000–1500 m elev. (Fig.
Distributions of A. byrsophyllus, A. punctulatus, A. spathulatus and A. tanaosriensis in Thailand and surrounding areas. Localities of A. byrsophyllus in Peninsular Malaysia were retrieved from
Karawek Kra.
Thailand: Loei Province, Phu Kradueng National Park, 24 Dec 1971, 1300 m, van Beusekom et al. 4555 (L); Nakhon Ratchasima Province, Pak Chong District, Khao Yai National Park, 1200 m, T. Insura 43; idem, T. Insura 101; idem, T. Insura 102; idem, T. Insura 103; idem, T. Insura 104 (KUFF); idem, U. Thongpairoj 235 (CMU).
Specimens of this species were mistakenly recognised as a new species (“A. sp. 5 (Kao Yai)”) by
1 | Young branches velutinous; abaxial surface of leaves densely hairy | 2 |
– | Young branches glabrous to sparsely hairy; abaxial surface of leaves glabrous to sparsely hairy | 3 |
2 | Leaf apex acuminate; leaf laminas broadly elliptic and coriaceous; petal blades 10–15 mm wide | A. siamensis |
– | Leaf apex caudate; leaf laminas oblong and chartaceous; petal blades 2–5 mm wide | A. uniflorus |
3 | Pedicels less than a quarter of the length of the flower | 4 |
– | Pedicels slightly shorter, as long as, or longer than flower | 6 |
4 | Petal blades linear, 1–2 mm wide; sepals ca. 3 mm long, ca. 2.5 mm wide; leaf laminas 10.5–19 cm long, 4–9 cm wide | A. tipuliferus |
– | Petal blades oblong-elliptic, 7–12 mm wide; sepals 4–10 mm long, 4–8 mm wide; leaf laminas 7–14 cm long, 2.5–4.2 cm wide | 5 |
5 | Inflorescences with up to 5 flowers; petal blades chartaceous, 2.8–3.3 cm long, 0.7–1 cm wide; monocarps distinctly stipitate (stipes 3–5 mm long) and slightly beaked (beak 1–2 mm long) | A. brevipes |
– | Inflorescences with a solitary flower; petal blades coriaceous, 3.5–4 cm long, ca. 1.2 cm wide; monocarps sessile and sharply beaked (beak up to 1 cm long) | A. oxycarpus |
6 | Stamen connectives apiculate | 7 |
– | Stamen connectives truncate | 8 |
7 | Young branches often with spines; leaf apex retuse, truncate or mucronate; leaf laminas 6–8 cm long, 2.5–4.5 cm wide; monocarps ellipsoid, 3.5–4.5 cm long, 1–2 cm wide | A. spinosus |
– | Young branches without spines, leaf apex acuminate; leaf laminas 9–15 cm long, 3–7 cm wide; monocarps obovoid, 3–3.5 cm long, 2–2.5 cm wide | A. harmandii |
8 | Petal blades terete; monocarps 1–2(–4) per fruit | A. suaveolens |
– | Petal blades not terete; monocarps 4–30 per fruit | 9 |
9 | Inflorescences with 10–20 flowers; monocarps not beaked | 10 |
– | Inflorescences with up to 4 flowers; monocarps beaked | 11 |
10 | Petals chartaceous, yellow (in fresh material); adaxial surface of inner petals with a short, raised rim between claw and blade (ca. 1 mm long); leaf laminas coriaceous | A. multiflorus |
– | Petals coriaceous, green to beige with maroon patches (in fresh material); adaxial surface of inner petals with an elongated, raised rim between claw and blade (ca. 5 mm long); leaf laminas chartaceous | A. punctulatus |
11 | Outer petals with externally distinct blades and claws; inner petal blades rhomboid or spathulate | 12 |
– | Outer petals without externally distinct blades and claws; inner petal blades ovate or triangular | 13 |
12 | Outer petal blades undulate; outer petal claws broadly ovate; inner petal blades rhomboid and undulate; monocarps slightly beaked (beak less than 1 mm long) | A. tanaosriensis |
– | Outer petal blades flat; outer petal claws broadly rhomboid; inner petal blades broadly spathulate and strongly concave; monocarps strongly beaked (beak ca. 2 mm long) | A. spathulatus |
13 | Leaf laminas chartaceous, 3–4 cm wide; leaf base asymmetrical; flowering pedicels 4–6 mm long; monocarps 2–2.5 cm long, 0.8–1.2 cm wide | A. oblanceolatus |
– | Leaf laminas coriaceous, 4–13.5 cm wide; leaf base symmetrical; flowering pedicels 10–25 mm long; monocarps 3–4.5 cm long, 2–3.5 cm wide | 14 |
14 | Leaf laminas 9–15.5 cm long, 4–7 cm wide; outer petals 1.5–2 cm long; monocarps ca. 6 per fruit, 4–4.5 cm long, 2–3.5 cm wide | A. venustus |
– | Leaf laminas 21–32 cm long, 8.5–13.5 cm wide; outer petals 1.3–1.6 cm long; monocarps ca. 20 per fruit, 3–3.5 cm long, ca. 2 cm wide | A. byrsophyllus |
We are grateful to: the directors of A, AAU, BKF, E, IBSC, K, KUFF, KUN, L, NY, PE, QBG, SING, U and US herbaria for the loan of, or access to, specimens; and Alicia Musson (K), Dr Ende Liu (KUN) and Siti Nur Bazilah Mohamed Ibrahim (SING) for access to high-resolution digital images of selected specimens. This research was funded by project 17109417 from the Hong Kong Research Grants Council, awarded to RMKS.