Hypericum microsepalum
| Hypericum microsepalum | |
|---|---|
| |
| Photo taken by Gil Nelson | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Magnoliophyta - Flowering plants |
| Class: | Magnoliopsida – Dicotyledons |
| Order: | Theales |
| Family: | Clusiaceae ⁄ Guttiferae |
| Genus: | Hypericum |
| Species: | H. microsepalum |
| Binomial name | |
| Hypericum microsepalum (Torr. & A. Gray) A. Gray ex S. Watson | |
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| Natural range of Hypericum microsepalum from USDA NRCS Plants Database. | |
Common name: flatwoods St. Johnswort
Synonym: Crookea microsepala (Torr. & A. Gray) Small
Contents
Taxonomic notes
Description
Hypericum microsepalum is an evergreen, arborescent plant that occurs along coastal ecoclines of the Florida panhandle (nomenclature follows Godfrey 1988).[1]
“Usually glabrous herbs or shrubs. Leaves usually punctate, simple, opposite, entire, usually sessile or subsessile, exstipulate. Inflorescence basically cymose; flowers perfect, regular, bracteates, subsessile or short-pedicellate, sepals 2, 4, or 5, persistent; petals 4 or 5, usually marcescent, yellow or pink; stamens 5-numerous, separate or connate basally forming 3-5 clusters or fascicles, filaments usually persistent; carpels 2-5, stigmas and styles separate or fused, ovary superior, 1-locular or partly or wholly 2-5 locular, placentation axile or parietal. Capsules basically ovoid, longitudinally dehiscent, styles usually persistent; seeds numerous, lustrous, areolate, cylindric or oblong. In general our species form a polymorphic complex with many intergrading taxa.” – Radford et al 1964
Distribution
Ecology
Hypericum microsepalum and H. brachyphyllum are shrubby in habit, producing multiple shoots from the base, whereas H. chapmanii produces a single stem with thick, flaky bark (Godfrey 1988; Robson 2003).[2] Hypericum microsepalum, in particular, has high survival when transplanted in lowland areas, but the populations quickly decline in the absence of fire.[3]
Habitat
Hypericum microsepalum (obligate resprouter) was associated with upland, drier pine savannas where fires are frequent and typically burn uniformly across landscapes (2–3 year fire frequency). Hypericum species had habitat associations with different elevation categories along ecoclines. Hypericum microsepalum had positive associations with upland plots and negative associations with intermediate and lowland plots.[3] It is found in Pine savanna and seepage bog community types of Florida.[4] H. microsepalum is also one of the most abundant seepage savanna shrubs that resprout from root crowns.[5] It generally occurs in sandy soil, and in addition to the native habitat types mentioned above, it can be found in some disturbed habitat, including roadsides (FSU Herbarium). Associated species includes Cyrilla parvifolia, Vaccinium darrowi, V. myrsinites, Ilex glabra, Polygala lutea, P. nana, Xyris brevifolia, Lyonia mariana, Myrica cerifera, Gaylussacia nana, Lobelia paludosa, Salix caroliniana Hypericum galioides, Myrica, Vaccinium, Aristida stricta, Ilex glabra, Pinus palustris, and Serenoa repens (FSU Herbarium).
Phenology
Flowering and fruiting have been observed in January through May, as well as in July (FSU Herbarium).
Seed dispersal
All species produce perfect flowers and dehiscent, septicidal capsules containing numerous seeds. Seeds are dispersed by gravity and occasionally by birds (Robson 2003).[6]
Seed bank and germination
All species have life spans 10 years and persistent seed banks.[3]
Fire ecology
“Biennial dormant and growing season fires affected Hypericum microsepalum. Stem densities were eight times greater after dormant season than growing season fires, but not significantly (P = 0.218). They also changed with time (P < 0.001), and were affected by treatment interactions (P = 0.039). Densities were 5 times greater after a first set of dormant season than growing season fires, but responses were variable (P = 0.258; Fig. 1b). Compared to initial levels, densities were 7 times greater after repeated dormant season fires (P < 0.001). After biennial growing season fires, densities were similar to those initially (P = 0.654). Densities were 13 times greater after repeated dormant season than growing season fires; this difference was not significant (P =0.060).”[5]
Pollination
Use by animals
Diseases and parasites
Conservation and Management
Cultivation and restoration
Photo Gallery
References and notes
Florida State University Robert K. Godfrey Herbarium database. URL: http://herbarium.bio.fsu.edu. Last accessed: June 2014. Collectors: John Jensen, Carl Noedman, Preston Adams, Robert K. Godfrey. Sidney McDaniel, Mark A Garland, Preston Adams, Walter S. Judd, Kent D. Perkins, Scott Zona, Loran C. Anderson, William P. Adams, Robert Kral, H. E. Grelen, M. Knott, L. B. Trott, Steve L. Orzell, M. Davis, K. M. Meyer, and A. Townesmith. States and Counties: Florida: Bay, Calhoun, Dixie, Franklin, Gulf, Jackson, Jefferson, Lafayette, Liberty, Madison, Marianna, Okaloosa, Santa Rosa, Taylor, Wakulla, and Walton. Georgia: Thomas.
- ↑ citations needed
- ↑ citations needed
- ↑ 3.0 3.1 3.2 Crandall, R. M. and W. J. Platt (2012). "Habitat and fire heterogeneity explain the co-occurrence of congeneric resprouter and reseeder Hypericum spp. along a Florida pine savanna ecoline." Plant Ecology 213: 1643-1654.
- ↑ Drewa, P., W. Platt, et al. (2002). "Community Structure along Elevation Gradients in Headwater Regions of Longleaf Pine Savannas." Plant Ecology 160(1): 61-78.
- ↑ 5.0 5.1 Drewa, P. B., J. M. Thaxton, et al. (2006). "Responses of root-crown bearing shrubs to differences in fire regimes in Pinus palustris (Longleaf pine) savannas: exploring old-growth questions in second-growth systems." Applied Vegetation Science 9: 27-36.
- ↑ citations needed
