Delphinium bhutanicum Munz (1967: 507)

Yuan, Qiong & Yang, Qin-Er, 2023, Taxonomic studies on the genus Delphinium (Ranunculaceae) from China (XXIII): Reduction of D. conaense to the synonymy of D. bhutanicum, a species newly reported for China, Phytotaxa 599 (5), pp. 291-300 : 292-299

publication ID	https://doi.org/ 10.11646/phytotaxa.599.5.3
DOI	https://doi.org/10.5281/zenodo.8044243
persistent identifier	https://treatment.plazi.org/id/039F87BA-FFBE-FFDA-6AF2-C0A9FECCFCA6
treatment provided by	Plazi
scientific name	Delphinium bhutanicum Munz (1967: 507)
status

Treatment

Delphinium bhutanicum Munz (1967: 507) View in CoL . Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 , 7 View FIGURE 7 .

Type:— BHUTAN. Trashi Yangtse, Me La, alt. 13000 ft, among scrub jungle, 25 August 1934, F. Ludlow & G. Sherriff 887 (holotype BM000570580!, isotype E00168757!). Fig. 1 View FIGURE 1 .

= Delphinium conaense Wang in Wang & Li (1987: 34), syn. nov.

Type:— CHINA. Xizang: Cona, southern slope of Bo Shan, alt. 3400–3500 m, moist places in forest, 10 September 1975, Qinghai-Xizang Supplement. Exped. 75–1959 (holotype PE00026974!, isotype KUN 1203909!). Fig. 3 View FIGURE 3 .

Description:—Perennial herbs. Rootstock often slightly thickened. Stems erect, slender, ca. 0.5−1 m high, distally laxly branched, more or less retrorsely strigulose throughout, scattered leafy. Lower leaves withered by anthesis; upper leaves 4−10 cm broad, divided almost to base into cuneate-rhombic segments, adaxially finely strigulose, abaxially more or less pubescent especially along the veins; segments 3-lobed about halfway, then lobulate into linear-lanceolate to lanceolate lobules 5−15 mm long, 2−5 mm broad; petioles 10−20 cm long, slightly dilated at base; uppermost leaves much reduced and bractlike. Inflorescence lax, 2- to few-flowered, subcorymbose, strigulose; upper bracts lanceolate, ca. 1 cm long; pedicels 2−5 cm long, suberect, strigulose; bracteoles broadly linear, 4−6 mm long, slightly below the flower. Flowers blue; sepals strigulose abaxially, the upper sepal broadly obovate, 1.5−1.6 cm long, 1.1−1.2 cm broad, subtruncate at apex, spur 1.5−1.6 cm long, ca. 3 mm broad at base, spreading-decurved, lateral sepals oblongobovate, ca. 1.6 cm long, ca. 8 mm broad, rounded at apex, lower sepals slightly shorter and wider; petals blue, lamina somewhat oblique, ca. 9 mm long, ca. 3 mm broad, glabrous, entire at the somewhat rounded tip, spur ca. 1.5 cm long; staminodes obovate, 8−9 mm long, 5−7 mm broad, bifid ca. 3 mm into 2 rounded-oblong lobes, white-bearded, the claw ca. 5 mm long; stamens 5−6 mm long, glabrous; carpels 3, densely pubescent. Follicles densely pubescent.

Distribution and habitat:— Delphinium bhutanicum is distributed in Bhutan and China (southern Xizang) ( Fig. 6 View FIGURE 6 ). It grows on alpine grassy slopes, in scrubs or in forests at altitudes of 3400–4000 m above sea level.

Phenology:—Flowering from August to September; fruiting from September to October.

Additional specimens examined:— BHUTAN. Bumthang, R.E. Cooper 2239 (E), F. Ludlow & G. Sherriff 19686 (BM); Trashi Yangtse, F. Ludlow & G. Sherriff 1016 (BM).

CHINA. Xizang: Cona, F. Ludlow & G. Sherriff 873 (BM), L. Wang et al. WL3146 (IBSC), L. Wang et al. WL3168 (IBSC); Lhunzê, F. Ludlow & G. Sherriff 2495 (BM000926556, BM000926557); Mêdog, F. Ludlow & G. Sherriff 2671 (BM000926561).

Notes:— Munz (1967) described Delphinium bhutanicum on the basis of five collections. These include R.E. Cooper 2239 (E; Fig. 2A View FIGURE 2 ), F. Ludlow & G. Sherriff 887 (BM, E; Fig. 1 View FIGURE 1 ), F. Ludlow & G. Sherriff 1016 (BM; Fig. 2B View FIGURE 2 ) and F. Ludlow & G. Sherriff 19686 (BM; Fig. 2C View FIGURE 2 ), all from Bhutan, and F. Ludlow & G. Sherriff 873 (BM; Fig. 2D View FIGURE 2 ) from Cona in southern Xizang, China, with the BM sheet of the second collection designated as holotype ( Fig. 1A View FIGURE 1 ). Grierson (1984) recognized this species, recording its occurrence only in northern Bhutan. Although one of the paratypes, F. Ludlow & G. Sherriff 873 ( Fig. 2D View FIGURE 2 ), was collected from Cona county in southern Xizang, China ( Fletcher 1975), the occurrence of this species in China has been previously totally overlooked. It was not recorded in any of the accounts of Delphinium in the Flora Reipublicae Popularis Sinicae vol. 27 ( Wang 1979), Flora Xizangica ( Wang 1985), and Flora of China ( Wang & Warnock 2001).

Wang in Wang & Li (1987) described Delphinium conaense on the basis of a single specimen, Qinghai-Xizang Supplem. Exped. 75-1959 (PE; Fig. 3A View FIGURE 3 ), also from Cona county in southern Xizang, China. In the protologue, the author stated that it was probably related to D. sparsiflorum Maximowicz (1877: 307) , but readily differed by having stems shorter, ca. 60 cm tall, densely white appressed puberulous (vs. taller, glabrous), inflorescence simple, short, densely white appressed puberulous (vs. compound racemose, glabrous), sepaline spur longer, 1.5 cm long (vs. shorter, 6–11 mm long), and pubescent (vs. glabrous) carpels. Our survey of Delphinium specimens at KUN resulted in discovery of an isotype of D. conaense (KUN; Fig. 3B View FIGURE 3 ), which has more flowers arranged in a subcorymbose inflorescence. Wang & Warnock (2001) and Wang (2020) recognized D. conaense as an independent species. A critical comparison of the type and non-type specimens, together with our critical observations on living plants in two populations in Cona ( Figs. 4 View FIGURE 4 , 5 View FIGURE 5 ), indicates that Delphinium conaense is indeed remarkably distinct from D. sparsiflorum , a species characterized by having glabrous stems, petioles, inflorescence axis, pedicels and carpels and also by having very small flowers with a short sepaline spur and distributed in eastern Qinghai, central and southern Gansu and southern Ningxia, China ( Wang 1979, 2020; Yuan & Yang 2016). In fact, the only point of superficial similarity between D. conaense and D. sparsiflorum lies in their 3-sect leaves. However, D. conaense is not essentially different from D. bhutanicum in any characters. The stems are rather slender, scattered leafy ( Figs. 4A View FIGURE 4 , 5 View FIGURE 5 ), retrorsely white puberulent ( Figs. 4B View FIGURE 4 , 5 View FIGURE 5 ); the leaves are 3-sect ( Figs. 4C View FIGURE 4 , 5 View FIGURE 5 ); the inflorescence is 2- to few-flowered, subcorymbose ( Figs. 4D, E View FIGURE 4 , 5 View FIGURE 5 ); the inflorescence axis and pedicels are appressed white puberulent ( Figs. 4F, G View FIGURE 4 , 5 View FIGURE 5 ); the bracteoles are broadly linear, slightly below the flower ( Figs. 4 I, J View FIGURE 4 , 5 View FIGURE 5 ); the carpels are pubescent ( Figs. 4J View FIGURE 4 , 5A View FIGURE 5 ). We therefore place D. conaense in synonymy with D. bhutanicum and report D. bhutanicum as a newly recorded species for China herein. In addition to the collection from Cona, our survey of specimens at BM resulted in discovery of another two collections of D. bhutanicum from southern Xizang, one from Lhunzê county and the other from Mêdog county ( Figs. 6 View FIGURE 6 , 7 View FIGURE 7 ).

Munz (1968) referred Delphinium bhutanicum to his informal group VI of the Asian species of Delphinium , placing it in the neighborhood of D. caeruleum Jacquemont ex Cambessedes in Jacquemont (1844: 7), a species widely distributed and very common in the Sino-Himalayan region ( Wang 1979, Wang & Warnock 2001, Yonekura 2008, Wang 2020). Morphologically D. bhutanicum is similar to D. caeruleum in having appressed puberulent stems, inflorescence axis and pedicels and usually a subcorymbose inflorescence, but differ immediately by the usual absence (vs. presence) of basal leaves and by having finely (vs. grossly) laciniate leaves and 3 (vs. 5) follicles per flower. From a morphological perspective it seems that these two species are only distantly related to each other and their relationship needs a further study.

In his recently published treatise on Chinese Delphinium, Wang (2020) cited a collection from Cona, PE Xizang Exped. 6212 (PE; Fig. 8A, B View FIGURE 8 ), under D. conaense , and he identified another collection from Cona, FLPH Tibet Exped. 12-0849 (PE; Fig. 8C, D View FIGURE 8 ), as D. conaense on the determination slip in 2013, but he did not cite it in this treatise. From their habit, leaf division and shape, inflorescence shape, and position of bracteoles, these two collections certainly do not belong to D. bhutanicum and may represent a hitherto undescribed species. We will describe this new species elsewhere. In addition, judging from the long, 20-flowered raceme and the leaf shape, the color photograph referred to D. conaense by Wang (2016) should belong to D. gyalanum Marquand &Airy-Shaw in Marquand (1929: 156), a species fairly common in Xizang.Although Wang (2016) stated that D. conaense was endemic to Cona in southern Xizang, this photograph was not taken in Cona, but in Lhunzê in southern Xizang by Dr. You-sheng Chen. Two voucher specimens of this photograph, Y.S. Chen et al. 13-0872 (PE02000415, https://www.cvh.ac.cn/spms/detail.php?id=e8244242; PE02000417, https://www.cvh.ac.cn/spms/detail.php?id=e82441b9), are kept at PE. Both specimens indeed belong to D. gyalanum .