Torreya dapanshanica X.F.Jin, Y.F.Lu & Zi L.Chen, 2022
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publication ID |
https://dx.doi.org/10.3897/phytokeys.192.79506 |
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persistent identifier |
https://treatment.plazi.org/id/70547570-5169-5861-BE75-8BA8E1AAC094 |
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treatment provided by |
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scientific name |
Torreya dapanshanica X.F.Jin, Y.F.Lu & Zi L.Chen |
| status |
sp. nov. |
Torreya dapanshanica X.F.Jin, Y.F.Lu & Zi L.Chen sp. nov.
Figs 1 View Figure 1 , 2 View Figure 2
Latin diagnosis.
Species nova haec T. jiulongshanensi (Z.Y.Li et al.) C.C.Pan et al. affinis est, sed a qua foliis apice acuminatis, basi cuneatis, seminibus late ovoideo-globosis vel globosis, basi obtusis, testis irregulariter et vadose canaliculatis differt.
Type.
China. Zhejiang: Pan’an, Mount Dapanshan, Huaxi , on slope under forest, 28°58'37.41"N, 120°30'00.01"E, alt. 420 m, 22 August 2017, Xiao-Feng Jin 4036B (holotype: ZM; isotypes: HTC, PE, ZJFC, ZM) GoogleMaps .
Trees evergreen, 5-8 m tall, with trunk to 25 cm d.b.h., dioecious; bark gray-brown, irregularly vertically fissured; branches glabrous, slightly shiny, with young branches green and biennial ones yellow-green or green. Leaves decussate, base coiled and 2-ranked; blade linear, (1.9-)3-5(-6.9) cm long, 2.7-3.2 mm wide, upper part slightly falcate, apex acuminate and spiculate, base cuneate, adaxially dark green, shinning, with mid-rib slightly concave, 2 grooves from base to near apex, abaxially green, with mid-rib slightly raised, 2 stomatal bands brown, each nearly equal to mid-rib in width, marginal band ca. 2 × as wide as stomatal band; petioles short, ca. 1 mm long, yellow-brown. Pollen cones solitary, axillary, ovoid-globose, 9-12 mm long, 7-9 mm wide, base shortly pedunculate; peduncles 3-3.5 mm long; bracts 5 or 6-pairs, decussate, abaxially ridged, lowermost 2 pairs smaller, green, papery, others yellow-green, thinly papery; microsporophylls 42-56, spiral in 6-8 whorls, triangular-ovate, membranous, 2-2.5 mm long, apex praemorse with 9 minute teeth, each with 4 pollen sacs abaxially; pollen sac yellow, ellipsoid, 1.2-1.5 mm long, ca. 0.8 mm wide, longitudinally divided. Seed-bearing structures borne in pairs in leaf axils, sessile, 6-7 mm long, each with 2 pairs of decussate bracts and 1 lateral bract; bracts sub-leathery, abaxially ridged. Aril succulent, base with persistent bracts; seed (including aril) obovoid, 3.5-4 cm long, 2-2.5 cm in diam., apex slightly convex with a mucro, seed (excluding aril) broadly ovoid-globose or globose, apex slightly emarginate, base obtuse-rounded; testa ligneous, stiff, with irregular shallow grooves; female gametophyte tissue deeply ruminate.
Distribution and habitat.
This new species is known only from Mount Dapanshan of Pan’an County, central Zhejiang. It grows at a single location on a forested slope by a stream margin at an elevation of 420-485 m.
Phenology.
Pollen cones observed from late early July to early the following April; ovules from mid-November to late the following April. Seeds mature from September to October.
Etymology.
The specific epithet ' Torreya dapanshanica ' refers to the type locality of the new species.
Conservation status.
Critically Endangered (CR) [B2ab(ii)D] (International Union for Conservation of Nature, IUCN 2019). The new species is only known from the type locality, Mount Dapanshan in Pan’an County, and occupies less than 1 km2 with about six mature individuals and two seedlings. Moreover, the habitat destruction and seed harvesting by local people still exist. This species is considered as Critically Endangered (CR) according to classification methods used by the IUCN Red List Categories and Criteria ( IUCN 2019) based on the current survey.
Specimen examined.
Zhejiang: Pan’an, Mount Dapanshan, Huaxi, in forest by stream, 28°58'37.41"N, 120°30'00.01"E, alt. 470 m, 24 November 2012, Xiao-Feng Jin & Ying-Ying Zhou 2938 (ZJFC, ZM), alt. 479 m, 24 November 2012, Xiao-Feng Jin & Ying-Ying Zhou 2940 (ZM); the same locality, on slope by stream, 28°58'33.39"N, 120°30'02.06"E, alt. 485 m, 7 April 2013, Xiao-Feng Jin 2953 (ZM), 25 July 2016, Xiao-Feng Jin 3831 (ZM), 3832 (ZM), 22 August 2017, Xiao-Feng Jin 4038B (ZM), 4039B (ZM); the same locality, in forest, alt. 450 m, 29 March 2020, Xiao-Feng Jin & Yi-Fei Lu 4547 (ZM), alt. 480 m, 29 March 2020, Xiao-Feng Jin & Yi-Fei Lu 4548 (ZM).
Comparison.
Teng et al. (2017) analyzed the leaf variation of all wild species of Torreya from Zhejiang, and found the leaves of T. grandis var. jiulongshanensis were different from those of T. grandis and T. jackii . Consequently, var. Torreya jackii jiulongshanensis was treated as an independent species and combined as T. jiulongshanensis . Within some populations identified as T. jiulongshanensis , Teng et al. (2017) mentioned that the leaves from the population in Pan’an were different from the others. Herein, we compared the leaf apex, and found that those from Pan’an ( T. dapanshanica ) are acuminate, whereas those from Suichang ( T. jiulongshanensis ) are acute (Fig. 3 View Figure 3 ).
Seed morphology of Torreya dapanshanica is also different from T. jiulongshanensis (Fig. 4 View Figure 4 ). The seeds of Torreya dapanshanica are broadly ovoid-globose or globose, 25.52 ± 3.52 mm × 15.62 ± 3.67 mm, apex slightly emarginate, base obtuse-rounded, testa with irregular shallow grooves. Torreya jiulongshanensis has seeds that are obovoid to narrowly obovoid, 22.56 ± 3.28 mm × 10.29 ± 2.23 mm, both apex and base acute, testa smooth or sometimes slightly concave.
A key to all known species of Torreya from China is shown below.
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