Boronia section Boronella (Baill.) Duretto & Bayly

Duretto, Marco F., Heslewood, Margaret M. & Bayly, Michael J., 2023, A molecular phylogeny of Boronia (Rutaceae): placement of enigmatic taxa and a revised infrageneric classification, Australian Systematic Botany 36 (2), pp. 81-106 : 102

Boronia section Boronella (Baill.) Duretto & Bayly , Austral. Syst. Bot. 28: 119 (2015)

Boronella Baill. , Adansonia 10: 302 (1872).

Type: Boronella pancheri Baill. [≡ Boronia pancheri (Baill.) Duretto & Bayly ].

Hairs simple. Branches, including cortex, strongly articulated at nodes, glabrous or with hairs at nodes, smooth or cuticle slightly exfoliating, not obviously glandular. Leaves verticillate in whorls of three or opposite–decussate, simple. Inflorescence a terminal cyme or pseudo-umbel, many-flowered; peduncle absent or present; bracts and bracteoles deciduous or apparently absent or so minute they are obscured by hairs at base of pedicels. Sepals imbricate or valvate in bud, persistent. Petals imbricate or valvate in bud, usually with a subterminal apiculum on abaxial surface, mostly multiveined from base or with steeply ascending basal lateral veins, persistent. Staminal filaments glabrous or hairy, swollen and verrucose towards apex, tip usually appearing subterminal adaxially. Stigma minute, not or slightly wider than style. Seed shiny, with a smooth sclerotesta, although cell walls visible; hilum usually adaxial and linear; raphe small and covered by brown outer testa; cotyledons elliptic or suborbicular, wider than hypocotyl.

A section of at least five species, of which four have been formally described, that is confined to Grande Terre, New Caledonia. A key to the described species of the genus Boronella has been provided by Hartley (1995). Here we present the first infrageneric classification for section Boronella , which includes two series.

Key to the series of Boronia section Boronella

1. Leaves verticillate in whorls of 3, sometimes also opposite–decussate on the same plant; branches glabrous apart from a dense indumentum in leaf axils and at base of inflorescence; petals imbricate in bud...................................................................series Boronella

Leaves opposite–decussate; branches glabrous; petals valvate in bud..........................................................................series Glabrae