Terniopsis yongtaiensis X.X. Su, Miao Zhang & Bing-Hua Chen, 2022

Zhang, Miao, Zhang, Xiao-Hui, Ge, Chang-Li & Chen, Bing-Hua, 2022, Terniopsis yongtaiensis (Podostemaceae), a new species from South East China based on morphological and genomic data, PhytoKeys 194, pp. 105-122 : 105

Terniopsis yongtaiensis X.X. Su, Miao Zhang & Bing-Hua Chen sp. nov.

Figs 1 , 2 , 3 , 4

Type.

China. Fujian: Yongtai County, Fuquan Town , elevation 95 m, 25°51'N, 118°52'E, 2 January 2022, Bing-Hua Chen CBH 04587 (Holotype, FNU!, barcode FNU0041314; isotypes FNU!, Barcode FNU0041315) .

Diagnosis.

Terniopsis yongtaiensis is similar to T. heterostaminata , a remarkable species from Thailand, by having single flower per flowering ramulus, similar ovary length, same shape of stigma and capsule. However, T. yongtaiensis has 2 fertile stamens, less number (1 vs. 1-3) but longer (13.0-21.9 mm vs. 1.4-14 mm) vegetative ramuli, less (1-2 vs. 1-4) but shorter (1.8-5.5 mm vs. 1.2-15 mm) flowering ramuli, shorter (1.1-2.5 mm vs. 1.7-7 mm) pedicels, shorter (1.9-3.1 mm vs. 2.5-8 mm) capsule-stalk, and shorter (1.1-1.3 mm vs. 1.5-3 mm) stamens.

The variations in morphology between T. yongtaiensis and the other two Terniopsis species from China, T. sessilis and T. daoyinensis , are more obvious. T. yongtaiensis shows clear differentiation between vegetative and reproductive stems, the erectness of the ramuli, and the characteristics of flower and fruit are distinctive from those of T. sessilis from Changting County, Fujian Province (Table 1 , Suppl. material 1: Figs S2-S4). However, T. daoyinensis from Hainan differs significantly from other species of the genus by its long (up to 1 mm) and distinctly multi-furcated stigmas (Table 1 ).

Description.

Perennial herbs. Ribbon-like roots, flattened to subcylindrical, 0.59 (0.30-1.07) mm wide, 0.58 mm thick, monopodially branched, adhering to rock surface, dark green in water, turns purplish-red or brick-red at flowering or when water is shallow; vegetative ramuli on both flanks of roots, upright, 17.58 (3.00-21.90) mm long, ca. 0.28 mm wide; leaves 48 (39-55), elliptic or spatulate, flattened, sessile, entire, subdistichous; the top leaves are usually larger than the basal ones, 1.73 (0.96-1.66) mm long, 0.65 (0.56-0.76) mm wide, the basal leaves gradually fall off during growth; flowering shoots grow lateral to vegetative ramuli, with a single flower and 1-2 associated upright ramuli, 3.14 (1.76-5.53) mm long, 0.31 mm wide, each has 24 (17-32) leaves, 0.93 (0.61-1.24) mm long, 0.53 (0.35-0.75) wide, elliptic or broad-ovate, tristichous, subequal, smaller than leaves on vegetative remuli (Fig. 1 ), all ramuli and leaves wither when fruiting. Flowers bisexual, small, solitary, petiolate, grows in axils of first leaves at base of flowering shoots; bracts 2, helmet-shaped, thinly membranous, pink or light red, 1.27 (1.08-1.61) mm long, 1.09 (0.80-1.45) mm wide; pedicel, 1.58 (1.13-2.52) mm long, ca. 0.41 mm in diameter; tepals, ca. 1.05 mm long, ca. 1.12 mm wide, shallowly lobed, lobes 3, red purple, semicircular, ca. 0.42 mm long, ca. 0.68 mm wide, lower part of tepals unite urceolated, turns to white when flowering; stamens 2, 1.21 (1.14-1.33) mm long, with introrse anthers, less than the perianth lobes, short filaments, segregate, base attached to ovary, 0.59 mm long; anthers 4, elliptic, 0.61 mm long, endocentric, rounded at the base. Ovaries elliptic, 3-locular, 1.13 (0.94-1.39) mm long, 1.03 (0.90-1.22) mm wide; ovules, 34 per locule; stigmas 3, padded, cristate, 0.16 mm tall, 0.49 mm long, 0.43 mm wide (Fig. 2 ). Capsule, 9-ribbed, obovoid, 1.15 (1.01-1.52) mm long, 0.98 (0.78-1.25) mm wide, fissured into 3 equal pieces at maturity; Capsules stalked, 2.48 (1.87-3.07) mm long; seeds ca. 25, green, teardrop-shaped, slightly concave at top, 0.21 (0.19- 0.24) mm long (Fig. 3 ).

Florescence December to January, fruiting season January to February.

Distribution, habitat and conservation status.

Terniopsis yongtaiensis is only known from Yongtai, Fujian, China (Suppl. material 1: Fig. S1), where it grows on rocks in unpolluted streams, sometimes covering the entire surface of the rock. Many other plants grow in the surrounding habitat, whose tree layer includes Ficus microcarpa L. f. ( Moraceae ), Prunus mume Sieb. ( Rosaceae ), Rhus chinensis Mill. Anacardiaceae , Schefflera heptaphylla (Linnaeus) Frodin ( Araliaceae ) and others;the shrub layer includes Ficus erecta Thunb. ( Moraceae ), Callicarpa kochiana Makino ( Lamiaceae ), Buddleja asiatica Lour. ( Scrophulariaceae ), Adina rubella Hance ( Rubiaceae ) and others; the vegetation layer includes Polygonum lapathifolium L. ( Polygonaceae ), P. chinense L. ( Polygonaceae ), Rubus hirsutus Thunb.( Rosaceae ), Ludwigia epilobioides Maxim.( Onagraceae ), Colocasia antiquorum Schott ( Araceae ), Panicum repens L. ( Poaceae ), Miscanthus floridulus (Lab.) Warb. ex Schum et Laut. ( Poaceae ), Neyraudia reynaudiana (kunth.) Keng ( Poaceae ), Isachne globosa (Thunb.) Kuntze ( Poaceae ), Saccharum arundinaceum Retz. ( Poaceae ), Commelina communis L. ( Commelinaceae ), Musa nana Lour. ( Musaceae ) and others; the interlayer plants includes Cocculus orbiculatus (L.) DC. ( Menispermaceae ), Pueraria montana (Loureiro) Merrill ( Fabaceae ) and others; and some exotic plants includes Alternanthera philoxeroides (Mart.) Griseb. ( Amaranthaceae ), Myriophyllum aquaticum (Vell.) Verdc. ( Haloragaceae ), Bidens pilosa L. ( Asteraceae ) and others.

Conservation status: According to our investigation, Terniopsis yongtaiensis was only found in a stream in Yongtai County, Fujian Province, China and hence, we suggest its placement in the Data Deficient category of IUCN (2022). In addition, according to the Updated List of National Key Protected Wild Plants (Decree No. 15) by the country’s State Forestry and Grassland Administration and the Ministry of Agriculture and Rural Affairs, all of the known genera of Podostemaceae found in China are classified as under national secondary protection. This new species should also be included on the national secondary protection list during the upcoming revision process.

Etymology.

The epithet Terniopsis yongtaiensis (永泰) refers to Yongtai County, Fujian Province where this new species was found.

Figures

Figure 1. A habitat B vegetative ramulus, upright, subdistichous (photo in aquarium) C leaf on the vegetative ramulus D leaf on the fertile ramulus E vegetative ramulus (left, long) and fertile ramulus (right, short) F fertile ramulus with tristichous leaves G flattened ribbon-like roots, (dark green in water) H subcylindrical roots (purplish-red at flowering or when water is shallow). Scale bars: 4 mm (B, H); 0.4 mm (C, D); 2 mm (E, G); 0.2 mm (F).

Figure 2. A branched flattened root with vegetative ramuli (red arrow) and young flower (shoot) on flank (photo in aquarium) B, C flower bud above bracts associated with short shoots (2 - ramuli), showing leaves in 3 ranks D Young shoot associated with two ramuli and broken vegetative ramulus E flowers F two flowers at anthesis, showing withered ramuli G flower subtended with 2 bracts at base and associated with ramuli, showing pedicel and urceolate corolla H bract I tepal J flower with 2 stamens K stamen L top oblique view of flower, showing 3 cristate stigmas M cross section of the ovary, showing three locules. Scale bars: 5 mm (A, E); 1 mm (B-D, F, G); 250 μm (H, I, J, L); 100 μm (K); 200 μm (M).

Figure 3. Terniopsis yongtaiensis A plants attached to stone surfaces in patches, withered after fruiting, banded-roots visible, in the dry season when the river level is reduced B habitat, showing ripe or nearly ripe fruits and withered roots C, D stalked fruit E fruit with 9 ribs F ripe fruits with dehiscent capsule, showing 3 lobes G seeds. Scale bars: 2 mm (B); 1 mm (C); 0.5 mm (D, E); 100 μm (F).

Figure 4. Illustration of Terniopsis yongtaiensis A vegetative ramulus (left, long) and fertile ramulus (right, short) B flower bud above bracts associated with short shoots (2 - ramuli) C flower subtended with 2 bracts at base and associated with ramulus D flower at anthesis, showing withered ramuli E fruit with 9 ribs F flower with urceolate corolla removed, 2 stamens on side of ovary G cristate stigmas H cross section of the ovary I stamen J seeds. Scales bars: 1 mm (A); 500 μm (B); 250 μm (C-H); 100 μm (I); 50 μm (J).