Thalictrum tsawarungense Wang & Wang (1979a: 618)

Zeng, You-Pai, Yuan, Qiong & Yang, Qin-Er, 2022, Lectotypification of Thalictrum chayuense (Ranunculaceae), with its reduction to the synonymy of T. tsawarungense, both described from Zayu in southeastern Xizang (Tibet), China, Phytotaxa 548 (2), pp. 184-198 : 196

Thalictrum tsawarungense Wang & Wang (1979a: 618) . Figs. 1 , 2B , 6‒11 .

Type:— CHINA. Xizang (Tibet): Zayu county, Tsa-wa-rung (= Chawalong town), Dzer-nar, on dry slope at margins of woods, alt. 3000 m, September 1935, C.W. Wang 66523 (holotype PE00028284!; isotypes GH00057586!, KUN0690108!, NAS00070715!, PE00028283!). Fig. 6 .

= T. chayuense Wang (1982a: 136) , syn. nov.

Type:— CHINA. Xizang (Tibet): near Zayu county, in mixed woods in ravine, alt. 2700 m, 29 June 1980, Z.C. Ni et al. 297 [lectotype PE00470107 (only the right fragment)!, designated here; isolectotype XZ0001665!]. Figs. 1 , 2B .

Description:—Perennial herbs. Roots fibrous. Stem 30‒80 cm tall, distally branched, glandular-pubescent. Leaves 2‒3-ternate; blade triangular, 5‒15 cm long, 4‒15 cm broad; leaflets broadly obovate, obliquely broadly obovate, suborbicular or broadly ovate, 0.5‒2 cm long, 0.5‒2 cm broad, herbaceous, both sides densely glandular-pubescent, adaxially green and abaxially pale green, base rounded or subcordate, apex obtuse or acute, 3-lobate; lobes entire or 1‒2-crenate, apex obtuse or acute; veins submerged adaxially, raised abaxially; petioles glandular-pubescent, 1‒3 cm long; stipules sheath-like or free, obliquely broadly ovate, membranous, margin entire. Inflorescence a panicle, few-flowered, leafy; rachis glandular-pubescent. Pedicels 1‒1.5 cm long, glandular-pubescent. Flowers bisexual. Sepals 4 or 5, elliptic, broadly elliptic ovate or broadly ovate, 2.2‒3.5 mm long, 1.5‒2.5 mm broad, abaxially sparsely glandular-pubescent, whitish or tinged with pinkish; basal nerves 3. Stamens 7‒13, 2.5‒4 mm long; filaments narrowly oblanceolate-linear, 1.8‒3 mm long, white; anthers narrowly oblong, 0.7‒1 mm long, ca. 0.5 mm broad, apex obtuse, yellowish. Carpels 1‒6, 2.5‒3 mm long, glandular-pubescent, stipitate; stipe ca. 0.3 mm long; ovary obliquely narrowly obovate, ca. 1 mm long; style ca. 2 mm long, straight or apically slightly recurved; stigma linear. Achenes 4.5‒7 mm long, glandular-pubescent, conspicuously stipitate; stipe 1‒2 mm long; body broadly compressed-lunate, shallowly ribbed; style persistent, apically slightly recurved.

Phenology:—Flowering from June to August; fruiting from July to September.

Distribution and habitat:— Thalictrum tsawarungense is widely distributed in western Sichuan and southeastern Xizang, China ( Fig. 12 ). It grows, often together with Berberis , Clematis , Quercus , Ribes , Rosa , or Spiraea species, in bushes in ravine or on slopes, in forests, or at forest margins at elevations of 2000–3800 m above sea level.

Additional specimens examined:— CHINA. Sichuan: Barkam, Anonymous 205 (NAS00187781, NAS00187782), K.Y. Lang, L.Q. Li & Y. Fei 2126 (KUN0691915, PE01108922, PE01108923); Daocheng, Sichuan Econ. Plant Exped. 105 (CDBI0026303, CDBI0026304, CDBI0026305); Jinchuan, S. Jiang et al. 1078 (KUN0690107, PE00450428, PE01040617, SZ00092639), H. Li 77456 (IBSC0090552, NAS, herb. no. 525773, PE00450425, PE00450426, PE00450427, WUK, herb. no. 234513); Kangding, X.J. He & Q.S. Zhao 183636 (SZ00578505, SZ00578517, SZ00578518), Kangding-Dawu Exped. 247 (SM704604894, SM, herb. no. 0335371), Y.P. Zeng & Q.L. Huang 411 (IBSC, barcode unavailable), Z.J. Zhao, J.B. Shi & D.G. Fan 114328 (CDBI0026498, SZ00092081, SZ00092082); Xiangcheng, Xiangcheng Exped. 410 (SM704604614, SM, herb. no. 0034924). Xizang (Tibet): Bomi, Y.T. Chang & K.Y. Lang 462 (PE00450382, PE00450383), W.Q. Fei 60 (IBSC, barcode unavailable), Inst. Bio. Xizang Exped. 376 (HNWP, herb. nos. 37148, 83680, 83681), Inst. Bio. Xizang Exped. 658 (HNWP, herb. nos. 37732, 84063), P.C. Kuo & W.Y. Wang 21884 (HNWP, herb. no. 66668), T. Naito et al. 983 (PE 02032612), Z.C. Ni et al. 127 (PE00450376, PE00450377, XZ0001695, XZ0001736), L. Wang, X.Q. Guo & Y.P. Zeng 3313 (IBSC, barcode unavailable), L. Wang, X.Q. Guo & Y.P. Zeng 3317 (IBSC, barcode unavailable), L. Wang, X.Q. Guo & Y.P. Zeng 3351 (IBSC, barcode unavailable), L. Xie BM 08 (PE00471599, PE00471600, PE00471601), Xizang Inst. Bio. Plant Res. Exped. 3976 (PE01040620, XZ0001698), T.S. Ying & D.Y. Hong 650136 (PE01962275, PE01962276), T.S. Ying & D.Y. Hong 650171 (PE00450399, PE00450400, PE00450401), T.S. Ying & D.Y. Hong 650251 (PE00450396), T.S. Ying & D.Y. Hong 650502 (PE00450402, PE00450403); Lhunze, Qinghai-Xizang Exped. Suppl. Group 750500 (HNWP, herb. nos. 51135, 96700, KUN0689479, PE00450386, PE00450387), Qinghai-Xizang Exped. Suppl. Group 750543 (HNWP, herb. nos. 51177, 77736, KUN0690358, KUN0690359, PE00450384, PE00450385); Mainling, B.S. Li & S.Z. Cheng 5394 (PE00450408, PE00450409), Qinghai-Xizang Exped. Suppl. Group 750915 (KUN0689475, KUN0689476, PE00450388); Markam, W.Q. Fei 17 (IBSC, barcode unavailable); Nyingchi, W.Q. Fei 66 (IBSC, barcode unavailable), J. Luo & S.L. Wang LuoJian-XZ-09113 (PE01900257); Zayu, Y.P. Zeng & Q.L. Huang 540 (IBSC, barcode unavailable), Y.P. Zeng & Q.L. Huang 553 (IBSC, barcode unavailable), Y.P. Zeng & Q.L. Huang 565 (IBSC, barcode unavailable), Y.P. Zeng & Q.L. Huang 568 (IBSC, barcode unavailable).

Figures

FIGURE 1. Holotype (A) sheet and close-ups of some parts (B‒I) of Thalictrum chayuense (= T. tsawarungense), showing that the sheet is mixed, consisting of two taxa. A. Left fragment (a): T. nepalense; right fragment (b): lectotype of T. chayuense (= T. tsawarungense). B. Portion of stem (glabrous) of the left fragment (a). C. Portion of leaf rachis (glabrous) of the left fragment (a). D. Portion of adaxial side of leaflet (glabrous) of the left fragment (a). E. Portion of abaxial side of leaflet (glabrous) of the left fragment (a). F. Portion of stem (glandular-pubescent) of the right fragment (b). G. Portion of abaxial side of leaflet (glandular-pubescent) of the right fragment (b). H. Flower of the right fragment (b). I. Aggregate fruit of the right fragment (b).

FIGURE 2. Two specimens numbered Z.C. Ni et al.297 and belonging to Thalictrum nepalense (A) and T. chayuense (= T.tsawarungense) (B, isolectotype) respectively. Inset: flower with sepals having fallen off.

FIGURE 6. Holotype and isotype sheets of Thalictrum tsawarungense.A. Holotype sheet (PE00028284) (inset a: flower; inset b: stamens; inset c: achene). B. Isotype sheet (GH00057586). C. Isotype sheet (NAS00070715). D. Isotype sheet (PE00028283).

FIGURE 7. Selected specimens of Thalictrum tsawarungense previously misidentified as T. rostellatum. A. China, Sichuan, Jinchuan, S. Jiang et al. 1078 (PE00450428) (inset: aggregate fruit). B. China, Sichuan, Kangding, Kangding-Dawu Exped. 247 (SM704604894) (inset: flower). C. China, Xizang, Bomi, Inst. Bio. Xizang Exped.376 (HNWP) (inset: aggregate fruit).D. China, Xizang, Lhunze, Qinghai- Xizang Exped. Suppl. Group 750543 (PE00450384) (inset: aggregate fruit).

FIGURE 8. Thalictrum chayuense (= T. tsawarungense) in the wild (China, Xizang, Zayu, the type locality). A. Habitat. B. Habit. C. Roots. D. Portion of stem. E. Leaf (left: adaxial side; right: abaxial side). F. Leaflet (adaxial side). G. Portion of adaxial side of leaflet. H. Portion of abaxial side of leaflet. I. Flower. J. Sepal (left: adaxial side; right: abaxial side). K. Stamens. L. Carpels. M. Aggregate fruits (immature). N. Achenes (immature). Photographed by Y.P. Zeng.

FIGURE 9. Specimens of Thalictrum chayuense (= T. tsawarungense), Y.P. Zeng & Q.L. Huang 565 (IBSC), from the type locality, i.e. Zayu in southeastern Xizang, China. Inset a: flower; inset b: aggregate fruit.

FIGURE 10. Thalictrum tsawarungense in the wild (China, Xizang, Zayu county, Chawalong (= Tsawarung), the type locality). A. Habitat. B. Habit. C. Roots. D. Portion of stem. E. Leaf (left: adaxial side; right: abaxial side). F. Leaflet (adaxial side). G. Portion of adaxial side of leaflet. H. Portion of abaxial side of leaflet. I. Flower. J. Sepal (left: adaxial side; right: abaxial side). K. Stamens. L. Carpels. M.Aggregate fruits (immature). N. Achenes (immature). Photographed by Y.P. Zeng.

FIGURE 11. Specimens of Thalictrum tsawarungense, Y.P. Zeng & Q.L. Huang 540 (IBSC), from the type locality, i.e. Chawalong (= Tsawarung) in Zayu, southeastern Xizang, China.A. Inset: flower. B. Inset: aggregate fruit.

FIGURE 12. Distribution of Thalictrum tsawarungense. Arrow indicates the type locality of both T. chayuense (= T. tsawarungense) and T. tsawarungense, i.e. Zayu in southeastern Xizang, China.