Samples of M. ericifolia leaves were obtained from 19 locations as follows: DL3104- 3110, Coopernook, New South Wales (NSW), 31° 49′ 31″ S, 152° 36′ 48″ E (Site No. 1); DL3114-3120, Hawks Nest, NSW, 32° 40′ 09″ S, 152° 10′ 12″ E (Site No. 2); DL3240-3244, Hexham, NSW, 32° 48′ 50″ S, 151° 42′ E (Site No. 3); DL3245-3249, The Entrance, NSW, 32° 22′ 24″ S, 151° 28′ 19″ E (Site No. 4); DL3397-3401, Tuggerah Lake, NSW, 33° 21′ S, 151° 27′ E (Site No. 5); DL3250-3254, Georges River, NSW, 33° 58′ 42″ S, 151° 00′ 14″ E (Site No. 6); DL3255-3259, Berry, NSW, 34° 46′ 37″ S, 150° 45′ 27″ E (Site No. 7); DL3260-3264, Lake Durras, NSW, 35° 36′ 00″ S, 150° 16′ 17″ E (Site No. 8); DL3265- 3269, Wallaga Lake, NSW, 36° 23′ 43″ S, 150° 03′ 04″ E (Site No. 9); DL3270-3274, Wallagoot, NSW, 36° 44′ 50″ S, 149° 55′ 46″ E (Site No. 10); DL3275-3279, Genoa, Victoria (Vic), 37° 25′ 56″ S, 149° 38′ 41″ E (Site No. 11); BVG3024- 3028, West of Lakes Entrance, Vic, 37° 48′ S, 148° 03′E (Site No. 12); BVG3014-3018, West of Lang Lang, Vic, 38° 13′ S, 145° 30′ 13″ E (Site No. 13); BVG3019-3023, East of Welshpool, Vic, 38° 38′ 28″ S, 146° 30′53″ E (Site No. 14); ACC1019/1-2, 5-7, Nelson on the Glenelg River, Vic, 38° 03′ S, 141° 00′ E (Site No. 15); KJ1-5, Airport Flinders Island, Tasmania (Tas), 40° 05′ S, 148° 00′ E (Site No. 16); KJ6-10, Lackrana Road Flinders Island, Tas, 40° 18′ S, 148° 06′ E (Site No. 17); ACR1848/1-3, Woolnorth Point, Tas, 40° 38′ 30″ S, 144° 43′ 30″ E (Site No. 18); JB4509, Robins Island Track, Tas, 40° 45′ S, 144°53′E (Site No. 19). The majority of samples were collected during June to December 1999 with the exceptions being sites 5, 15 and 18, which were collected during July to October 2000. Leaf material totaling about 100 g of fresh leaves and twigs was obtained mainly from five widely spaced individual trees per location.

Oil composition varied quantitatively throughout the species range rather than qualitatively in an apparent association with latitude of occurrence. Linalool and linalool oxide were abundant in the oils from the north of the species range in New South Wales with a gradual southerly decline in these compounds to central Victoria with concomitant increase in the proportions of 1,8-cineole, alpha-terpineol and limonene. The most southerly populations sampled in southern Victoria and Tasmania gave oils containing relatively high proportions of 1,8-cineole (mean 34.5%) and low proportions of linalool (3%). Four populations from the Central Coast of NSW (Coopernook, Hawks Nest, The Entrance and Tuggerah Lake) provided the greatest opportunity of identifying seed trees that combine the attributes required for plantation development. The tree that had the best combination of oil traits (DL 3116 from Hawks Nest) had an oil yield of 4.5%, a linalool content of 60% and a 1,8-cineole content of 16%.