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Blandfordia nobilis Smith (Liliaceae) is a small herbaceous monocotyledon that resprouts from a rhizomatous corm after fire. The complex pattern of flowering shown in the five years following a fire in January 1987 was investigated for five populations near Sydney. This pattern was then related to concurrent changes in soil chemistry. Most (60%) plants flowered in the first post-fire flowering season (November-January), but this dropped to fewer than 20% of the plants flowering by the third or fourth season. Most plants flowered only once, but almost all plants did flower. Consequently, 35% of the flowering events were by plants that flowered only within the first year. Flowering in the first season produced more flowers per plant in that season, and was also correlated with increased chance that a plant would flower again. Repeat flowering produced fewer flowers per plant in the subsequent seasons, but multiple flowering did increase the total number of flowers produced per plant. This form of pulse flowering and short secondary juvenile period after fire seems to be typical of resprouting monocotyledons in Australia, but is much less common among resprouting dicotyledons. The pulse of flowering appears to be closely associated with changes in the soil chemistry during the post-fire period. Many of the soil attributes measured show either a characteristic decrease or increase during the 3-4 years following the fire, with a subsequent reversal in the trend. The plants thus flower prolifically during these changing soil conditions, but almost cease flowering when these changes are reversed, thereby taking advantage of soil conditions that are not available throughout most of the inter-fire period.

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Evidence is presented for the existence of two genecoiogically differentiated groups in Leptospermum flavescens in the Sydney region. A morphologicai study of 18 attributes of herbarium specimens indicates three groups of plants: one small-leaved, one large-leaved and one intermediate. Comparative cultivation under standard conditions and seed germination experiments indicate only two discrete groups, because the intermediate group behaves similarly to the large-leaved group. Correlation of population distribution with soil nutrient status suggests that organ size in the large-leaved group is phenotypically plastic in relation to low soil nutrients. This is confirmed by comparative cultivation under high and low nutrient regimes. Reciprocal transplanting of cuttings on a small scale suggests that the two groups are intolerant of each other's habitats.

In the Sydney region, many plants from populations on windswept headlands have a more prostrate growth habit compared with plants from populations of the same species occurring away from the coast. To determine whether these different growth habits are genetically determined, plants from four populations of each of five species (Acacia rnyrtifolia, Acacia suaveolens, Banksia ericifolia, Casuarina distyla, Hakea teretifolia) were grown under uniform glasshouse conditions. Multivariate analyses of six morphological characteristics indicate that, for four of these species, the offspring are similar to their maternal parent; we thus conclude that the habit differences are genetically fixed in these populations. The same trend is apparent for C. distyla, although significant variation occurs in the offspring. Univariate analyses indicate that different characteristics reflect the habit differences in different species. For conservation biology, the implications of this intra-specific variation are that attempts should be made to conserve viable populations of all genetically isolated taxa within a species.