BERBERIS EXTENSIFLORA (BERBERIDACEAE): A NEW RANK FOR BERBERIS CONCINNA VAR. EXTENSIFLORA

The new rank and combination Berberis extensiflora (Ahrendt) Bh.Adhikari & Harber is proposed based on morphological and molecular studies of the Himalayan species of Berberis (Berberidaceae). Morphologically, Berberis extensiflora differs from B. concinna Hook.f. by its much longer (3–4 cm) inflorescence with 2 or 3 flowers in umbels (vs < 2 cm long solitary flowers) and 10-to 13-seeded berries (vs 5-to 9-seeded berries). A detailed taxonomic description, notes on habitat and ecology, and colour photographs are provided.


Introduction
Berberis L., the largest genus of Berberidaceae, is likely to contain 400-500 species (see Harber, 2020, for more details), but the total number worldwide is uncertain. Berberis is represented by 21 species in Nepal (Adhikari et al., 2012), 55 in India (Rao et al., 1998a(Rao et al., , 1998b, and at least 278 in China (Harber, 2020).

Materials and methods
This report is based on field observations, DNA studies, and examination of herbarium specimens of Himalayan species of Berberis. The second author (J. Harber) also studied living collections of Berberis concinna Hook.f. and B. concinna var. extensiflora Ahrendt. Additionally, herbarium specimens (including types) from BM, E and KATH (herbarium codes follow Thiers et al., continuously updated) were examined, and the relevant literature (Adhikari et al., 2012;Harber, 2020) was consulted. All the specimens collected were deposited at E and KATH herbaria.

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A new rank for Berberis concinna var. extensiflora The descriptions in Hooker andThomson (1855, 1872) were even briefer. Neither of the descriptions gave the length of the pedicels. Ahrendt (1945) published Berberis concinna var. brevior (as breviora) on the basis that it had shorter pedicels and narrower fruit than B. concinna, with its type being from Nepal. Subsequently, Ahrendt (1961) provided the first full description of Berberis concinna, while also maintaining Berberis var. brevior and publishing a further variety, Berberis var. extensiflora Ahrendt, whose type and four additional specimens cited (all with berries) were from Nepal. Berberis var. extensiflora was distinguished from Berberis var. concinna and Berberis var. brevior by having an umbellate infructescence. Adhikari et al. (2012) The conclusion that Berberis var. extensiflora represents a separate species came from two independent morphological and molecular studies. The first author (B. Adhikari) examined wild populations of Berberis var. concinna and Berberis var. extensiflora in the Nepal Himalaya, while the second author (J. Harber) studied living collections of both varieties concinna and extensiflora at Foster Clough, Mytholmroyd, West Yorkshire. In 2018, Harber observed that the flower structures of two plants from Nepal in his living collection, both grown from wild-collected seed, differed significantly.
Following Schneider's little-known observations (in German) on the importance of flower structures as key criteria in differentiating species of Berberis (Schneider 1916(Schneider , 1939(Schneider , 1942reported in Harber, 2020), Harber concluded that despite some similarity of their leaves (Figure 1), these were in fact two separate species.
Quite independently, Kreuzer (2017) found that molecular analysis also showed Berberis var. concinna and Berberis var. extensiflora to be genetically distantly related. The phylogeny of Berberis from the Himalaya and Hengduan mountains, which was based on nuclear and plastid genes, placed Berberis var. concinna and Berberis var. extensiflora in two different clades (Kreuzer, 2017).

Morphological differences between Berberis concinna and B. extensiflora
The Table summarises morphological differences between Berberis concinna and B. extensiflora. It should be noted that the description of the apex of the petals of Berberis   Figure 2.
Distribution. Berberis extensiflora has been collected in central and western Nepal.
Habitat and ecology. Berberis extensiflora is found among slash vegetation, in open areas on dry slopes, and in Rhododendron forests at 3150-3350 m. It has been collected in flower from June to August and in fruit in October.