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Telopea 8(4): 2000 
Phenology: flowers chiefly October to November; ripe fruit recorded mostly February 
to April. 
Conservation Status: listed as 'Davidsonia sp A Mullumbimby-Currimbin [sic] Ck (A.G. 
Floyd 1595)' in New South Wales as an endangered species on Schedule 1 of the 
Threatened Species Conservation Act, 1995; 2ECi on the ROTAP list (Briggs & Leigh 
1996).This species is only known to occur in one gazetted reserve. Snows Gully Nature 
Reserve in New South Wales. Tire largest populations at Huonbrook and Upper 
Burringbar are on private properties; present owners are actively involved in the 
conservation and rehabilitation of disturbed rainforest. Threats to the species include 
general clearing of remnant pockets of rainforest and the likely narrow genetic base in 
a limited set of small populations. 
There are some important questions arising as to the dispersal of the species and its 
future in the wild. Flowers are formed regularly and prolifically, but as indicated in the 
species description no pollen has been detected in mature anthers and ovaries are 
small or lacking, sometimes vestigial and often the styles are reduced or absent. 
Ovules are usually absent — but in one collection two or three abortive shrivelled 
ovules were present in each of the two loculi. Fruit are produced abundantly and are 
well-developed but the pyrenes are always empty and no seed has ever been found. 
From our own field observations and communications with others that are familiar 
with field populations (G. Watson, A.G. Floyd, D.L. Jones) the species relies on root 
suckers for reproduction. This vegetative reproductive process readily enables present 
stands to propagate, but it does not account for the species distribution in populations 
scattered over 120 kms. Unless, as suggested by Watson (1987), aboriginal people were 
involved with the vegetative spread of this species over its geographic range. Or, 
alternatively is it possible that very rarely fertile seeds are formed, with subsequent 
dispersal and establishment of seedlings. 
Derivation of name: named in honour of the late Dr L.A.S. Johnson who during the 
past 49 years made outstanding contributions to systematic botany, rainforest floristics 
and to the understanding of the Australian flora while on the staff and as Director, and 
latei as Director Emeritus, of the Royal Botanic Gardens Sydney. Lawrie Johnson 
annotated specimens of this taxon in 1949, the year after he joined the staff of the 
Gardens, as 'clearly a new species'. 
Discussion: a specimen of this taxon collected in 1936 at Nimbin by King (BRI) was 
cited by Bange (1952) as 'variety dubious'. Specimens deposited at Coffs Harbour 
Forestry Herbarium (now CFSHB) collected by Floyd and Hayes at The Pocket in 1958 
and Watson at Thieles Gate, Huonbrook in 1978 were originally not separated as a new 
taxon. It was not until Watson brought the plants to the attention of the authors in 1978 
that it was further investigated and the differences from the other two taxa were 
clarified. 
Common names: Smooth Davidsonia (Williams et al. 1984), Smooth Davidson's Plum 
(Floyd 1989, Harden 1990), Small4eaved Davidson's Plum (Floyd 1989). 
Selected specimens (from 21 examined): Queensland: Moreton: Olson's Property, Currumbin 
Valley, Jones s.n., 10 Jan 1982 (NSW 389182, BRI, CANB, NE). 
SctfuT, l !lu Wal t!;, NOrth C ° aSt: Ho § ans Sc* -1 *' North Tumbulgum, Floyd 1827, 8 Dec 1981 (NSW, 
CFSHB); Whian Whian, Chee! s.n., 6 Sept 1926 (NSW 104890); Mooball, near Murwillumbah, Flowers 
s „"’' 2 Ma y 1944 (NSW 104891); 5.2 km west of Burringbar on property of M. Lickfold, Williams, 
mp pp 1980 (NSW 389176 ' A ' AD ' B ' BR1 ' CANB '™, HO. K, L, LE, MO, 
G.,'‘ b ' 1 RE 'V S 'Burringbar Range, end of track 1.7 km N of Upper Burringbar, 22°25'S 
153 27 E, Davws 1564a & Richardson, 27 Feb 1990 (CANB, NSW, BRI, MEL); Nimbin, King s.n., 2 Mar 
