[Bournea]
Important notes
The genus Bournea is presently not accepted. It has been included in Oreocharis by Möller et al., Phytotaxa 23: 1-36 (2011). The recent suggestion of Chen et al. (PhytoKeys 157: 27-41, 2020) to keep Bournea separate, is not followed here (for the reasons see Möller et al., Edinburgh J. Botany (2023) and the notes below).
The names of the two species of erstwhile Bournea now read: Oreocharis leiophylla W.T.Wang, O. sinensis (Oliv.) Mich.Möller & A.Weber.
Bournea (in its traditional sense)
Bournea sinensis Oliv., type species
T.S.Ying et al. (1993), The endemic genera of seed plants of China, Fig. 104.1; with permission
Bournea sinensis Oliv., type species
Z.Y.Li & Y.Z.Wang (2004), Plants of Gesneriaceae in China, Fig. 1.7; with permission
Bournea sinensis Oliv., type species
Z.Y.Li & Y.Z.Wang (2004), Plants of Gesneriaceae in China, Fig. 1.7; with permission
Bournea leiophylla (W.T.Wang) W.T.Wang & K.Y.Pan
Z.Y.Li & Y.Z.Wang (2004), Plants of Gesneriaceae in China, Fig. 1.5; with permission
Bournea leiophylla (W.T.Wang) W.T.Wang & K.Y.Pan
Z.Y.Li & Y.Z.Wang (2004), Plants of Gesneriaceae in China, Fig. 1.4; with permission
Bournea (in its traditional sense)
Full name and orig. publication: Bournea Oliv., in Hook. f., Icon. pl., ser. 4, 23, tab. 2254 (May 1893).
Etymology: Named after F.S.A. Bourne, a British businessman and botanical collector in China (between 1896 and 1898).
Synonyms: -
Infrafamilial position: Didymocarpoid Gesneriaceae - "Advanced Asiatic and Malesian genera" (Weber 2004).
Description: Perennial, acaulescent rosette herbs. Leaves petiolate; petiole densely strigose or villose; lamina ovate to oblong-ovate, margin entire or crenate-sinuate, both surfaces strigose. Cymes umbelliform, peduncle long, densely strigose; bracteoles fairly long, linear-lanceolate. Sepals 4 or 5, narrowly triangular, puberulous outside. Corolla equalling calyx in length, purple, campanulate, 4- or 5-lobed, lobes equal, rounded. Stamens 4 or 5, slightly exserted; filaments inserted in throat between the corolla lobes; anthers dorsifixed, thecae parallel, locules apically not confluent. Nectary cyathiform. Ovary slender cylindrical; style short; stigma bilobed. Capsule linear-oblanceolate, bivalved, dehiscence loculicidal.
Chromosome number: Unknown.
Species number: 2.
Species names: (1) B. leiophylla (W.T.Wang) W.T.Wang & K.Y.Pan, (2) B. sinensis Oliv.
Type species: Bournea sinensis Oliv.
Distribution: SE China (Guangdong, SW Fujian).
Ecology: Growing on rocks in forests, in shady places and by the sides of streams; 300-1000 m.
Notes:
(1) The genus Bournea has been synonymised with Oreocharis by Möller et al. (2011), based on the analysis of two DNA sequences (trnL-F and ITS) and on the result that the two species appeared in separate positions of the phylogenetic tree. On grounds of the similarity of the two species (habit, umbelliform inflorescences and actinomorphic flowers) and the analysis of seven sequences Chen et al. (2020) recently produced a new phylogeny in which the two species formed a clade sister to all remaining species of Oreocharis. Consequently, the authors suggested to keep Bournea separate from Oreocharis (but did not take formal-nomenclatural action). While the morphological arguments are plausible, it was shown most recently by Möller et al. (2023) that the available molecular data are not sufficient to provide unambiguous evidence for separation. It is, therefore, recommended to leave Bournea in synonymy until the relationships of the two species and the more than hundred species of Oreocharis become better known.
(2) Characteristic of traditional Bournea are the regular, 4- or 5-merous campanulate corolla, which scarcely overtops the calyx, and the scapose, umbelliform cymes with long bracteoles.
Selected references: Wang et al. in Wu & Raven (eds.), Fl. China 18: 249-250 (1998); Möller et al., Phytotaxa 23: 1-36 (2011), inclus. in Oreocharis; Chen et al., PhytoKeys 157: 27-41 (2020), see Notes.
Tax. details, cytology, and bibliography: Gesneriaceae Resource Centre (GRC). Royal Botanic Garden Edinburgh.
Page content responsibility/contact: Michael Möller.
The page is not updated as long as Bournea remains in synonymy.