Acacia redolens

Overview

Acacia redolens occurs at Western Australian salt-lake margins and on mildly saline or alkaline soils. Craig et al. compared seedlings from different saltland provenances and reported source-soil ECe, irrigation-water ECw, survival and biomass separately. [S2, S4]

Names and classification

Acacia redolens Maslin. The native-range material includes populations on salt-lake margins and on mildly saline or alkaline soils. The experiment separately identified higher- and lower-salinity seed sources, including Ravensthorpe. [S1, S2, S4, S5]

Morphology and identification

This Western Australian species is a prostrate to low shrub with flattened phyllodes, yellow spherical flower heads and flat pods. Phyllode form, venation, inflorescences and pods help distinguish similar wattles in the field; salinity-response differences among provenances are not taxonomic characters. [S2, S4]

Distribution, habitat and phenology

Flora-derived Wattle records place the species on mildly saline or alkaline loams, clays and clay loams, often at salt-lake margins. Craig et al. also compared seed sources from differently saline Ravensthorpe sites. [S1, S2, S4, S5]

The regional sources cited here do not report a consistent flowering or fruiting season. [S5]

Salinity in natural habitats

Western Australian records support an association with salt-lake margins and mildly saline habitats. Craig et al. further linked source-site salinity with seedling responses among provenances; this is provenance-level evidence, not a continuous root-zone exposure for an individual plant. [S1, S2, S4]

Salinity studies

The higher- and moderate-salinity source areas were reported at ECe >2200 and about 1100 mS/m, respectively. Craig et al. measured natural source soils by saturated-paste extract at depths of 50–600 mm; Table 2 reports EC variation by site, year and soil layer. These provenance comparisons are not continuous root-zone exposures for individual plants. [S1]

Ravensthorpe-source seedlings had 100% survival after 12 weeks of saline irrigation at final ECw 9500 mS/m; Figure 5 separately reports shoot biomass. [S1]

eHALOPH’s maximum-salinity field lists 9.5 dS/m and cites Craig et al. (1990). This converts to 950 mS/m, one-tenth of the paper’s final irrigation-water ECw of 9500 mS/m. The database does not identify the material or endpoint represented by its field, and the unit or transcription discrepancy remains unresolved. [S3]

Reported mechanisms and ecological adaptations

Seedlings from higher- and moderate-salinity provenances differed in leaf sodium accumulation, indicating variation among sources. Survival and biomass after 12 weeks are separate endpoints and do not establish a whole-life-cycle tolerance mechanism. [S1, S2, S4]

Conclusions and evidence gaps

Salt-lake-margin records and Craig et al.’s provenance experiment support an association with Western Australian saltlands. Ravensthorpe-source seedlings all survived salt-only irrigation at final ECw 9500 mS/m, and Figure 5 separately reports shoot biomass. eHALOPH’s 9.5 dS/m converts to 950 mS/m, tenfold lower than the paper’s reading; the reason is unresolved. [S1, S2, S3, S4]