Restringing some coral beads — nomenclatural notes on Nertera (Rubiaceae)

Geophila humifusa is reduced to the synonymy of Nertera granadensis. A new combination, Nertera major, is proposed to replace Nertera assurgens, as the name for a species endemic to Tristan da Cunha. Nine lectotypes are designated.


Introduction
The genus Nertera Banks ex Gaertn.(Rubiaceae: Rubioideae: Anthospermeae: Coprosminae) consists of about 12 species of small, creeping herbs, bearing fleshy, often brightly coloured berries.Like its larger sister genus Coprosma J.R.Forst.& G.Forst., it exhibits a trans-Pacific distribution with a centre of diversity in New Zealand (6 species) (Gardner 1999), though Nertera also occurs on mainland South America, in the Caribbean and on some South Atlantic islands.The one widespread species in the genus, Nertera granadensis (Mutis ex L.f.) Druce, the coral-bead plant, is cultivated as a pot plant for the decorative nature of its persistent berries, and cultivars with white, yellow, orange or red fruits are now available.
A research project on Chassalia Comm.ex Poir.and Geophila D.Don required a review of all the published names in these two genera.The work on Geophila uncovered a new synonym of Nertera granadensis.While confirming the details of the synonymy and typification of this taxon, it was also noticed that there is a longstanding nomenclatural problem with another of the Nertera species, which is also addressed here.
Nertera granadensis is treated in the broad sense here, however, it is beyond the scope of this study to revise the species across its entire range.Many local forms have been given formal taxonomic identities, but these have mostly been relegated to synonymy by subsequent workers (Wagner et al. 1999).
Gaertner (1788: 124) referred to "Ex herbario Banksiano.Habitat in regionibus antarcticis" in the protologue of Nertera depressa, which was described solely in terms of its fruit and seed characters.Andersson (1993) referred to the holotype of N. depressa as a Banks specimen from Antarctica in K.There is no such specimen, so this typification is not considered effective.There is no material in TUB (U.Grünert pers.Comm.) either, where Gaertner's carpological collection is now located.There is a Banks and Solander specimen from Tierra del Fuego in BM.The specimen does not currently bear fruits, but there is a painting (TF33), made by Sydney Parkinson (Banks's draughtsman), of a fruiting specimen from Tierra del Fuego (Diment et al. 1987) and there is also a specimen and illustration from New Zealand, but this is of a flowering plant, so it seems most likely that Gaertner's material came from Tierra del Fuego.Therefore, as there are no fruits or seeds available from the original collection to verify the description, Gaertner's illustration is here selected as a lectotype.
A Junghuhn specimen, with a label in Miquel's hand giving the taxon name, is designated here as a lectotype for Nertera depressa f. acutifolia.
The true identity of Geophila humifusa King & Gamble has likely escaped attention because apparently no material was distributed from the Calcutta Herbarium.The late F. R. Fosberg saw the material in CAL and annotated one sheet as type, but never published these findings.This sheet is here designated as a lectotype and the formal recognition of a new synonym of Nertera granadensis confirmed.Brown (1905) reported a syntype of his Nertera depressa var.obtusa to have been collected on 16 Aug.1873, but the only specimen that otherwise fits the citation is noted as being collected on 16 Oct. 1873.I take this to be a citation error on Brown's part and select the specimen as a lectotype.
Hochreutiner (1934) referred a number of his collections to Nertera granadensis var.javanica.The best specimen in G is here selected as a lectotype.
Fosberg annotated a specimen in BISH as a lectotype of Nertera granadensis var.insularis, but this selection was never published.To avoid future confusion, the specimen is here designated as a lectotype.the species number in the text for Erythrodanum majus.'Nertera assurgens Thouars' does not therefore class as an alternative name, as Petit-Thouars clearly accepted Erythrodanum majus as the correct name for the species and did not accept Nertera assurgens.This is reflected on p. 47 where the index of generic names lists Erythrodanum in the style of an accepted name, listing the numbers 92 and 93 associated with the two species in the account, and omits Nertera altogether.Therefore, the oldest name for the species is Erythrodanum majus and this is here transferred to Nertera, to assign the correct name to the species.Groves (1981) referred to the Petit-Thouars specimen, in P, as the holotype of Nertera assurgens Thouars, but, as this name is not validly published, it cannot stand as a lectotypification.I, therefore, here select the P specimen as lectotype of Erythrodanum majus Thouars, and there is also a Petit-Thouars specimen in BM, which may, or may not, be a duplicate.