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CEGL007083 Isoetes lithophila - Isoetes melanopoda - Crassula aquatica - Callitriche peploides Granite Pool Vegetation
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Rock Quillwort - Blackfoot Quillwort - Water Pygmyweed - Matted Water-starwort Granite Pool Vegetation
Colloquial Name: Central Texas Granite Ephemeral Pool Vegetation
Hierarchy Level: Association
Type Concept: This vegetation is endemic to freshwater rock pools on granitic flatrocks and domes of the Llano Uplift of central Texas. These are characterized by Isoetes lithophila, Isoetes melanopoda, Anagallis minima, Bacopa rotundifolia, Callitriche heterophylla, Crassula aquatica, Elatine brachysperma, Heteranthera limosa, Lepuropetalon spathulatum, Mimulus glabratus var. jamesii, Pilularia americana, Juncus diffusissimus, and Plantago heterophylla.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This is a very distinctive vegetation type which is restricted to seasonally flooded pools on granitic outcrops in the Central Mineral Region of the Edwards Plateau of central Texas.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This granitic pool vegetation is dominated by emergent herbaceous annuals and perennials which tolerate flooding. These central Texas examples occur in freshwater rock pools on granite outcrops of the Llano Uplift. Pools may be dominated by Isoetes spp., including Isoetes lithophila and Isoetes melanopoda, which are emergent or submerged fern allies, but which look like graminoid plants. The pool vegetation is additionally characterized by Anagallis minima, Bacopa rotundifolia, Callitriche heterophylla, Callitriche peploides, Crassula aquatica, Elatine brachysperma, Heteranthera limosa, Leptochloa fusca ssp. fascicularis (= Leptochloa fascicularis), Lepuropetalon spathulatum, Mimulus glabratus var. jamesii, Pilularia americana, Plantago heterophylla, Juncus diffusissimus, and Riccia nigrella (a perennial liverwort) (Whitehouse 1933, Walters and Wyatt 1982, Holmes et al. 2005, as cited in Poole et al. 2007, Singhurst et al 2007).
Dynamics: No Data Available
Environmental Description: This vegetation is restricted to seasonally flooded pools on granitic outcrops of the Llano Uplift of the Edwards Plateau in central Texas. These can occur on granitic domes, or on granite flatrock outcrops. These pools hold water for several weeks in the winter and spring, but dry out in late spring and become very dry in summer. The temperature, dissolved oxygen, dissolved carbon dioxide, and pH of the water in vernal pools can vary significantly over a 24-hour period (Keeley and Zedler 1998b). At the surface of the outcrops, summer temperatures can reach 120°F. This combination of flooding for several weeks and very hot and dry summer conditions represents an extreme habitat. Singhurst et al. (2007) documented 34 vernal pools at Mason Mountain Wildlife Management Area (Mason County, Texas). These seasonal isolated wetlands form in depressions of the Katemcy Granite Formation (late Precambrian), and are restricted to eroded depressions in the granite domes within the Sedum nuttallianum - Selaginella peruviana granite outcrops. Each pool has an independent hydrology.
The Llano Uplift, also known as the Central Mineral Region of Texas, is generally lower in elevation than the surrounding Edwards Plateau, though named as an uplift because it is an intrusion of Precambrian metamorphic rocks and large granitic massifs (Walters and Wyatt 1982, Riskind and Diamond 1988). At a regional scale, it is a topographic bowl, though rock outcrops such as Enchanted Rock often produce dramatic increases in elevation at a local scale. Aside from these massif intrusions, topography is generally level to rolling. The substrate is composed of granites, gneisses and schists. Elevation ranges from 251 to 686 m above sea level (825-2250 feet). Rainfall averages about 76 cm (30 inches), peaking in May or June and September. The Central Mineral Region occupies approximately 1.5 million hectares in central Texas (Riskind and Diamond 1988). Mineralogy of the granitic material varies, with hornblende schist, graphite schist, quartz-feldspar gneiss and quartz-plagioclase-microcline rock common (Riskind and Diamond 1988).
The Llano Uplift, also known as the Central Mineral Region of Texas, is generally lower in elevation than the surrounding Edwards Plateau, though named as an uplift because it is an intrusion of Precambrian metamorphic rocks and large granitic massifs (Walters and Wyatt 1982, Riskind and Diamond 1988). At a regional scale, it is a topographic bowl, though rock outcrops such as Enchanted Rock often produce dramatic increases in elevation at a local scale. Aside from these massif intrusions, topography is generally level to rolling. The substrate is composed of granites, gneisses and schists. Elevation ranges from 251 to 686 m above sea level (825-2250 feet). Rainfall averages about 76 cm (30 inches), peaking in May or June and September. The Central Mineral Region occupies approximately 1.5 million hectares in central Texas (Riskind and Diamond 1988). Mineralogy of the granitic material varies, with hornblende schist, graphite schist, quartz-feldspar gneiss and quartz-plagioclase-microcline rock common (Riskind and Diamond 1988).
Geographic Range: This vegetation is restricted to the Llano Uplift of the Edwards Plateau in central Texas.
Nations: US
States/Provinces: TX
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.949675
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: G1?
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.C Shrub & Herb Wetland Subclass | S44 | 2.C |
| Formation | 2.C.4 Temperate to Polar Freshwater Marsh, Wet Meadow & Shrubland Formation | F013 | 2.C.4 |
| Division | 2.C.4.Nd Eastern North American Temperate Freshwater Marsh, Wet Meadow & Shrubland Division | D323 | 2.C.4.Nd |
| Macrogroup | 2.C.4.Nd.2 Broadleaf Cattail - White Snakeroot - Rush species Marsh, Wet Meadow & Shrubland Macrogroup | M069 | 2.C.4.Nd.2 |
| Group | 2.C.4.Nd.2.c Quillwort species - American Pillwort - Greater Water-starwort Granite Outcrop Pool Group | G803 | 2.C.4.Nd.2.c |
| Alliance | A1817 Quillwort species - Poolsprite Granitic Outcrop Pool Alliance | A1817 | 2.C.4.Nd.2.c |
| Association | CEGL007083 Rock Quillwort - Blackfoot Quillwort - Water Pygmyweed - Matted Water-starwort Granite Pool Vegetation | CEGL007083 | 2.C.4.Nd.2.c |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: < Ponds, Springs, and Vernal pools (Singhurst et al. 2007)
= Vernal pool (Singhurst et al. 2007)
= Vernal pool (Singhurst et al. 2007)
- Keeley, J. E., and B. A. Morton. 1982. Distribution of diurnal acid metabolism in submerged aquatic plants outside the genus Isoetes. Photosynthetica 16:546-553.
- Keeley, J. E., and P. H. Zedler. 1998b. Characterization and global distribution of vernal pools. Pages 1-14 in: C. W. Witham, E. T. Bauder, D. Belk, W. R. Ferren, Jr., and R. Ornduff, editors. Ecology, conservation, and management of vernal pool ecosystems. Proceedings from the 1996 conference. California Native Plant Society, Sacramento, CA.
- Poole, J. M., W. R. Carr, D. M. Price and J. R. Singhurst. 2007. Rare plants of Texas. Texas A & M University Press, College Station, Texas. 640 pp.
- Riskind, D. H., and D. D. Diamond. 1988. An introduction to environments and vegetation. Pages 1-15 in: B. B. Amos and F. R. Gehlbach, editors. Edwards Plateau vegetation: Plant ecological studies in central Texas. Baylor University Press, Waco, TX.
- Shure, D. J. 1999. Granite outcrops of the southeastern United States. Pages 99-118 in: R. C. Anderson, J. S. Fralish, and J. M. Baskin, editors. Savannas, Barrens, and Rock Outcrop Plant Communities of North America. Cambridge University Press.
- Singhurst, J. R., L. L. Sanchez, D. Frels, Jr., T. W. Schwertner, M. Mitchell, S. Moren, and W. C. Holmes. 2007. The vascular flora of Mason Mountain Wildlife Management Area, Mason County, Texas. Southeastern Naturalist 6(4):683-692.
- Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.
- Walters, T. W., and R. Wyatt. 1982. The vascular flora of granite outcrops in the Central Mineral Region of Texas. Bulletin of the Torrey Botanical Club 109:344-364.
- Whitehouse, E. 1933. Plant succession on central Texas granite. Ecology 14:391-405.