Virotia azurea (Proteaceae: Macadamieae), a striking new species endemic to New Caledonia and notes on V. francii and V. leptophylla

Helen C.F Hopkins,Yohan Pillon

doi:10.15553/c2020v751a9

Abstract

Hopkins, H.C.F. & Y. Pillon (2020). Virotia azurea (Proteaceae: Macadamieae), a striking new species endemic to New Caledonia and notes on V. francii and V. leptophylla. In English, English and French abstracts. Candollea 75: 89–98.Virotia azurea H.C. Hopkins & Pillon (Proteaceae), the seventh species in the endemic genus Virotia L.A.S. Johnson & B.G. Briggs from New Caledonia is described and illustrated. A distribution map and preliminary conservation assessment are provided. This new species occurs principally on non-ultramafic substrates in a restricted area of central Grande Terre. It has relatively long narrow leaves, often with distally undulate-sinuate or bluntly toothed margins and a pointed apex, plus blue flowers and laterally flattened, markedly beaked fruits containing seeds with blue to mauve cotyledons. Its characters are compared with those of other species of Virotia and a key to species is provided. A handful of specimens previously identified as Virotia francii (Guillaumin) P.H. Weston & A.R. Mast are determinated mostly as Virotia leptophylla (Guillaumin) L.A.S. Johnson & B.G. Briggs and other species; the former is now confined to ultramafic substrates in southern Grande Terre and the latter is more widespread, principally occurring on non-ultramafic substrates though occasionally found on ultramafic ones in the south of the island as well.

Highlights

We describe here a seventh species of Virotia from New Caledonia, V. azurea H.C
Some material of Virotia azurea was previously identified as V. francii
These two species are not sympatric and morphologically, V. francii can be distinguished by its leaves, which typically have shorter blades, usually borne on longer petioles, and they have an intramarginal vein that extends along the entire length of the leaf

Summary

Introduction

Virotia L.A.S. Johnson & B.G. Briggs is a genus of Proteaceae endemic to Grande Terre, the main island of New Caledonia (Weston & Barker, 2006; Weston, 2007). Virot (1968) regarded the stem of the Y as fused pedicels and the scales at the junction between the free and fused sections as bracteoles, but Johnson & Briggs (1975) considered these misnomers They referred to the stem of the Y as a peduncle (called a common peduncle by Weston, 2007) and the scales as floral bracts. Three collections of this new species at P (MacKee 15159, 18031, 28793) bear determination slips on which Virot indicated the name Macadamia francii (Guillaumin) Sleumer ( Virotia francii (Guillaumin) P.H. Weston & A.R. Mast) and a few additional specimens have been equated with V. francii by other botanists.

Key to the species of Virotia

Taxonomic treatment

NUM central