Australian Journal of Taxonomy

Xylosma craynii W.E.Cooper is newly described from the Wet Tropics bioregion of north-eastern Queens-land. The new species is illustrated and notes on habitat and distribution are provided.


Introduction
Xylosma G.Forst. has previously been classified within the family Flacourtiaceae Rich. ex DC. Recent molecular work has shown Xylosma to belong to the willow family Salicaceae Mirb. Chase et al. (2002). According to Christenhusz et al. (2017) the genus Xylosma comprises about 85 species occurring in South East Asia, Malesia, the Pacific, Australia and America. Jessup (1984) revised Xylosma in Australia and recognised four species, with X. ovata Benth. and X. terraereginae C.T.White & Sleumer occurring in Qld and NSW (Jessup 1982) and X. maidenii Sleumer and X. parvifolia Jessup being endemic to Lord Howe Island. Specimens of a previously undescribed taxon have been collected since that revision and with this publication there are now five Xylosma species described from Australia.
The new Xylosma described herein was first collected by G. Sankowsky in 1985. Xylosma craynii W.E.Cooper sp. nov. flowers and fruits during the prolonged wet season typical of the mountain rainforests in the tropics, making access to the plants difficult. However, in recent years collections of fertile material of both sexes have been successful.
The specific delimination of this rather large genus is very difficult, as neither flowers nor fruits yield good or distinctive characters. However, the differences, though small, or even minute, seem to hold (Sleumer 1954:66). Malesian Xylosma species as revised by Sleumer (1954) possess some features which differ variously from all Australian species. Australian specimens lack spines, have stipules, a rudimentary ovary is sometimes present in male flowers, and the disk may be 7-18-lobed rather than 4-8-lobed. Features that are consistent with previously published Xylosma descriptions include articulate pedicels, imbricate sepals, the lack of petals, a glandular disk, flowers seemingly perfect in some specimens, a rudimentary ovary present in some flowers within each inflorescence, a berry that is fleshy not dry, and seeds usually few to 12 (with the exception of X. craynii, which has approximately 40 seeds per fruit).

Phenology. Flowers have been recorded in March and
May, and fruit in September and November. Notes. Xylosma congesta (Loureiro) Merrill, which occurs in India, China, Taiwan, Japan and Korea, is more similar to X. craynii than any other Australian species and has therefore been used for comparison in the diagnosis of the new species. X. craynii is unusual in the number of ovules and seeds (c. 40) compared with other Xylosma species, which have up to 12.

Conservation status.
There are no immediate threats evident for the species. Using GeoCat (Bachman et al 2011) based on known locations, Extent of Occurrence is estimated at 27 km 2 , and Area of Occupancy is estimated at 32 km 2 . A suggested conservation status for Xylosma craynii is Endangered [ENB1ab(i, iii)+B2ab(i, iii)] (IUCN 2012).

Notes on typification.
There are two herbarium sheets and one spirit sample of W. Cooper 2752 + R. Jensen held at CNS, all clearly labelled as being parts of a single specimen. They thus constitute holotype material rather than being duplicates (see ICN Art. 8.3;Turland et al. 2018).

Disclosures
There are no disclosures or conflicts of interest to be declared.