Assessment of Leitneria floridana in Disjunct Native Habitats: Implications for Horticulture and Conservation

Abstract

Tolerance of shade, flooding, drought, and nutrient-poor substrate is desirable among ornamental plants installed in managed landscapes. Many attractive native taxa have not been evaluated for their resistance to environmental stressors. We assessed Florida corkwood (Leitneria floridana Chapman) in its natural habitat in four disjunct populations in the United States and tested the physical and chemical properties of the soil at the study sites. Measures at all sites were made within two weeks in late June, 2003. Leaf area, plant height, length of new shoots, and the rate of photosynthesis were higher among plants receiving more than 600 μmol·m-2·s-1 of photosynthetically active radiation (PAR) compared to plants that occurred where maximum PAR was lower. Soil texture ranged from clay loam to fine sand, and soil pH across sites was 4.5 to 6.6. Concentration of nitrate-nitrogen, phosphorus, and potassium ranged from 3 to 75 mg·L-1, 7 to 11 mg·L-1, and 3 to 64 mg·L-1, respectively. Bases of plants in Florida were submersed in water, while soil moisture percentages in Missouri and Texas were 6 to 30. The apparent tolerance of L. floridana to shade, low and high soil moisture, and nutrient-poor soil in native habitats indicates that it could be used in a wide range of managed landscapes. Its capacity to adapt to shade may permit the use of L. floridana as an understory species in managed landscapes, but stewards of natural areas may need to maintain open sites within its native habitat to allow expansion of populations. Because this assessment of L. floridana included native populations across the natural range of the species, our results are uniquely suited for both horticultural and ecological interpretation and application.