Identity
Unique IDELEMENT_GLOBAL.2.132707
Element CodePDMAL0H0E0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderMalvales
FamilyMalvaceae
GenusHibiscus
Other Common NamesNeeches River Rose-Mallow (EN)
Concept ReferenceKartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic CommentsGenetic studies confirm that Hibiscus dasycalyx is a valid species, distinct from other sympatric Hibiscus species (Mendoza 2004 in Parris 2009).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2020-03-18
Change Date1989-09-21
Edition Date2020-03-18
Edition AuthorsBrown, B.A. (1985), rev. Poole/Maybury (1996), rev. Maybury (2002), rev. L. Morse (2005), rev. A. Tomaino (2010), rev. Treher (2020)
Threat ImpactVery high
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences1 - 5
Rank ReasonsHibiscus dasycalyx is a Texas endemic found only in wetlands of the East Texas Pineywoods Ecoregion. Eight extant populations are known but three of those are historic. The species has been introduced numerous sites. Populations have been subjected to heavy herbicide use in the past, and that, along with mowing, continues to be a threat. In addition, all of the occurrences are subject to genetic swamping by more common Hibiscus species that are perhaps better adapted to human-disturbed conditions. One of the biggest threats to the species is competition with other plants including non-native species and aggressive, woody native species.
Range Extent CommentsHibiscus dasycalyx is endemic to east Texas and known only from Cherokee, Harrison, Houston, and Trinity counties(Poole et al. 2007). Extent of occurrence is calculated using occurrences natural occurrences with plants seen within the last 20 years (EO data in the NatureServe central database as of November 2020).
Occurrences CommentsThere are eight natural populations are known to be extant or thought to be extant. One occurrence is extirpated. In addition, the species has been introduced at eight sites (USFWS 2018).
Threat Impact CommentsHibiscus dasycalyx is primarily threatened by competition and displacement by invasive (Chinese Tallow, Triadica sebifera) and aggressive native species, like sweetgum (Liquidambar styraciflua). It is also threatened by herbicide use and inappropriate mowing on highway right-of-ways and private lands (USFWS 2010). All right-of-way populations are small or have been extirpated (USFWS 2010). Also seriously threatened by hybridization with other Hibiscus species that are invading some sites due to habitat alteration (USFWS 2010). Other major threats include cattle grazing resulting in soil compaction and trampling, wetland drainage and filling, wetland conversion to stock ponds, and water-table changes (USFWS 2010). Drought can also be threatening: extreme drought occurred in 1998-2001 and short-term droughts have continued to occur in recent years (USFWS 2010).