Leavenworthia aurea var. texana
|Texas Golden Glade Cress, golden gladecress|
|David C. Berkshire|
The following Participating Institutions are custodians for this species in the CPC National Collection:
Mercer Arboretum and Botanic Gardens
The conservation of Leavenworthia aurea var. texana is fully sponsored.
David C. Berkshire contributed to this Plant Profile.
A pretty little winter annual less than 1 dm tall. Leaves in a basal rosette, lyrately lobed with a large terminal lobe and several smaller lateral lobes, to about 5 cm long, glabrous, the terminal lobe usually wider than long, the margin usually angularly toothed. Flowers borne on scapes 3-9 cm or, later in the season, in racemes on lateral decumbent branches; sepals 4, 4-5 mm long; petals 4, bright golden-yellow with a slightly darker base, narrowly obovate, 7-10 mm long, emarginate at the apex (with aging); stamens 6; style 2-3.5 mm long. Fruit a silique flattened parallel to the septum, erect, 1.5-3 cm long and about 5 mm wide, with sinuous rather than straight margins (somewhat constricted between the seeds), containing several orbicular seeds 3.5-4.5 mm in diameter (Correll & Johnston 1979; Mahler 1987).
U.S Army officer, Dr. M. C. Leavenworth, discovered the Texas Golden Glade Cress and another rare endemic, White Bladderpod, Lesquerella pallida, on small prairies near San Augustine, Texas in the 1830s. Both Texas Golden Glade Cress and White Bladderpod only occur in the wild on shallow calciumcontaining soils on ironstone outcrops of unusual geological regions called the Weches Formation. The Weches Formation is composed of bands of ancient marine sediments that lie parallel to the Gulf Coast from Sabine to Frio Counties. In East Texas, these alkaline "islands" of soil contrast the surrounding acid soils of the Pineywoods. The thin top layer of these alkaline sediments contains fossilized calcium-containing marine shells and the mineral glauconite. The glades remain saturated during rainy periods and then become very dry during the heat of the summer (W.F. Mahler, 1981).
The seeds of these species normally begin to germinate on the glades during fall rains and the plants over winter as small tap-rooted plantlets.
FLOWER PHENOLIOGY: Flowering and fruiting late February to April or May
Distribution & Occurrence
Occurs within oak-hickory-pine forests within the Pineywoods of the Coastal Plain region of East Texas. L. aurea var. texana is found within these forests on rocky outcrops of an unusual geological region called the Weches formation. The Weches formation is a band of ancient marine sediments that lies parallel to the Gulf Coast from Sabine to Frio Counties. In East Texas, these alkaline "islands" of soil contrast the surrounding acid soils in this region of the Pineywoods. The thin top layer of these alkaline sediments contains fossilized calcium, potassium and magnesium-containing marine shells and covers a layer of grayish-green impermeable glauconite clay that oxidizes to a reddish-brown color. This clay traps water and remains saturated during rainy periods and becomes very dry during the heat of the summer. The soils of the Weches outcrops are of the Trawick and Nacogdoches series (R. Turner 2001).
|4 sites, numbers range from a few hundred to a few thousand plants per site|
Conservation, Ecology & Research
Rare East Texas plants found in Weches outcrops include Sedum pulchellum, Calylophus drummondianus, Liatris mucronata, Paranychia virginica, Petalostemum pulcherrimum, Heliotropium tenellum, Eleocharis compressa and Cuphea viscosissima (George and Nixon 1990; Correll and Johnston 1979; Berkshire 1998). Other plants found as companions to L. pallida may include: Asclepias verticillata, Boerhaavia erecta, Calylophus berlandieri ssp. berlandieri, Cahamaecrista fasciculata, Cuphea viscosissima, Dracopsis amplexicaulis, Erigeron strigosus, Galactia volubilis, Mirabilis collina, Modiola caroliniana, Monarda citriodora, Oxalis dillenii, Palafoxia rosea, Polanisia dodecandra ssp. trachysperma, Polanisia erosa var. erosa, Portulaca oleracea, Sabatia campestris, Solanum carolinense, Stachys crenata, Triodanis perfoliata and Verbena haleiand others (Correll and Johnston 1979; Berkshire 1998). Woody species common to the deeper soil strata of the Weches outcrops include Gleditsia triacanthos, Liquidambar styraciflua, Rosa bracteata, Juniperus virginiana, Forestiera ligustrina, Rhamnus lanceolata, Cornus drummondii and Cissus incisa (George and Nixon, 1990).
Also extremely vulnerable to:
Trampling, overgrazing, herbicides for treatm
Mercer, Lady Bird Johnson Wildflower Center, Austin, TX and the National Seed Storage Laboratory in Ft. Collins, CO maintain seed banks for this species
Selection of reintroduction sites maintenance of suitable sites.
Encourage landowners to preserve existing populations.
Controlled burns and targeted herbicide treatments limited to July-October should be conducted wherever possible.
Selected logging around populations to increase its range with concurrent management of competitive vegetation.
Controlled grazing may be utilized to suppress competing vegetation where possible.
Surveys for unknown populations.
Continue monitoring sites.
Continued selection of potential reintroduction sites.
Continued research to determine life history, pollination and germination requirements.
Correll, D.S.; Correll, H.B. 1975. Aquatic and wetland plants of southwestern United States. 2 vols. Stanford. Stanford University Press.
Poole, J.M.; Carr, W.R.; Price, D.M.; Singhurst, J.R. 2007. Rare Plants of Texas. College Station, TX. Texas A&M University Press. 640p.