Subiculum not seen. Stromata (500)530 ± 27(550) µm high, (550)80 ± 21(600) µm wide ( n = 5), conical with a large, wide conical top, black, solitary or crowded in small groups, sometimes up to three fused together, some of them with stromatal margin, confluent over the whole substrate in crowded areas. Ostioles undifferentiated. Ectostroma 25-50 µm thick, black. Entostroma absent in mature material. Perithecia remaining attached to the stromata. Ascus apical rings (10.5)11.5 ± 0.7(12.5) µm long, upper width 7.6-8.6 µm, lower width 6.7-7.7 µm (n = 5), J+, dark blue. Ascospores (38.4)42.2 ± 2.3(47) µm long, (9.1)10.3 ± 0.7(11.5) µm wide (n = 30), inequilaterally ellipsoidal, dark brown, with straight germ slit extending over the whole spore length, both extremities and convex side surrounded by a slimy sheath, 2-3 µm thick and 5-6 µm wide at spore ends.
ANAMORPH: Unknown.

HOST: Rhopalostylis baueri var. cheesemanii.
MATRIX: Rachides.

Subiculum non visum. Stromata (500)530 ± 27(550) µm alta, (550)580 ± 21(600) µm lata, conica, apice magno, late conico praedita, nigra, solitaria ad gregibus parvis gregaria, interdum ad tria stromata connata, margine stromatico interdum presenti, in regiones substrati totius conferta. Ostiola indistincta. Annulus apicalis asci (10.5)11.5 ± 0.7(12.5) µm altus, parte superiore 7.6-8.6 µm et inferiore 6.7- 7.7 µm latus, iodo valde coerulescenti. Ascosporae(38.4)42.2 ± 2.3(47) µm longae, (9.1)10.3 ± 0.7(11.5) µm latae, asymmetrice ellipsoideae, atrobrunneae, fissura germinativa recta totam ascosporam recurrenti praeditae, vagina mucosa 2- 3 µm crassa 5-6 µm ad apicibus lataque circumdatae.

ETYMOLOGY: According to the host family.
NOTES: Rosellinia palmae is characterised by conical stromata with distinctive tops and undifferentiated ostioles. Ascospores are mid-sized with two slimy caps and a long germ slit. Only the type collection is known and does not show a subiculum. The ascus apical ring, however, is typical of Rosellinia spp.This species differs from R. radiciperda by stromatal characters, the absence of a subiculum in mature material, and ascospores without a cellular appendage. In addition to stromatal characters, R. palmae can be distinguished from R. longispora by smaller ascospores and ascus apical rings and from R. novae-zelandiae by larger ascospores of different shape without a cellular appendage. Rosellinia lamprospora Syd. resembles R. palmae; however, the former has larger, pear-shaped stromata and larger ascospores lacking a slimy sheath (L. E. Petrini unpubl. data). R. formosana has stromata of a similar shape as R. palmae, but they are larger and the ascospores are more than twice as long (Ju & Rogers 1999)

HOLOTYPUS (hic designatus): New Zealand, Kermadec Islands, Raoul Island, on Rhopalostylis baueri var. cheesemanii, orchard, 20 Sep 1988, E. H. C. McKenzie, PDD 54730.