Species of Greatest Conservation Need

**Species of Greatest Conservation Need** (Updated: 06/16/2025)
Scientifc Name	Common Name	Taxonomic Group	SGCN Status	Federal Status	State Status	Global Rank	State Rank	Endemic	General Habitat Type(s)
Cirsium wrightii	Wright's marsh thistle	Plants	Yes	T 05/25/2023	Not Listed	G2	S1	No	Marshy wetlands (cienegas) near springs in otherwise semi-arid to arid areas. It requires saturated soils with surface or subsurface water flow (USFWS 2015).
Clematis carrizoensis	Carrizo Sands leather-flower	Plants	Yes	Not Listed	Not Listed	G2	S2	Yes	Occurs in the margins of post oak woodlands on deep sands of Carrizo formation (Carr 2015). Flowering April-August (sometimes as late as October).
Clematis texensis	scarlet leather-flower	Plants	Yes	Not Listed	Not Listed	G3G4	S3S4	Yes	Usually in oak-juniper woodlands in mesic rocky limestone canyons or along perennial streams; Perennial; Flowering March-July; Fruiting May-July
Cleomella longipes	stalked rhombopod	Plants	Yes	Not Listed	Not Listed	G3G4	S3	No	Locally common in sparingly vegetated sandy or alkaline soils and along margins of seasonal wetlands in the Trans-Pecos (Carr 2015).
Colubrina stricta	Comal snakewood	Plants	Yes	Not Listed	Not Listed	G2	S1	No	In El Paso County, found in a patch of thorny shrubs in colluvial deposits and sandy soils at the base of an igneous rock outcrop; the historic Comal County record does not describe the habitat; in Mexico ,found in shrublands on calcareous, gravelly, clay soils with woody associates; flowering late spring or early summer
Coreopsis intermedia	goldenwave tickseed	Plants	Yes	Not Listed	Not Listed	G3	S3	No	In deep sandy soils of sandhills in openings in or along margins of post oak woodlands and pine-oak forests of east Texas; Perennial; Flowering/Fruiting May-Aug
Coryphantha macromeris var. runyonii	Runyon's cory cactus	Plants	Yes	Not Listed	Not Listed	G5T2T3	S2S3	No	Gravelly to sandy or clayey, calcareous, sometimes gypsiferous or saline soils, often over the Catahoula and Frio formations, on gentle hills and slopes to the flats between, at elevations ranging from 10 to 150 m (30 to 500 ft); ?late spring or early summer, November, fruit has been collected in August
Coryphantha nickelsiae	Nickels' cory cactus	Plants	Yes	Not Listed	Not Listed	G2	SH	No	Limestone outcrops and nearby alluvial or gravelly soils on hills or plains in grasslands or shrublands at low elevations; known sites in Mexico have been described as Chihuahuan Desert scrub; flowering August through September
Coryphantha ramillosa ssp. ramillosa	bunched cory cactus	Plants	Yes	T 11/06/1979	T 04/01/2005	G2G3T2T3	S2S3	No	Rocky slopes, ledges, and flats in the Chihuahuan Desert, most frequently on exposures of Santa Elena or Buda limestones or the Boquillas Formation between 400-1070 m (1300-3500 ft) in elevation; flowering August-November, perhaps as early as April in response to rainfall.
Coryphantha scheeri var. uncinata	Scheer's cory cactus	Plants	Yes	Not Listed	Not Listed	G4TUQ	S2	No	Rocky hillsides (Carr 2015).
Crataegus mollis var. viburnifolia	sawtooth hawthorn	Plants	Yes	Not Listed	Not Listed	G3	S3	Yes	Rich alluvial soil, brushy habitats (Phipps 2015); Borders of woods and low ground (Correll and Johnston 1970); Flowering Mar; fruiting Sep�Oct.
Crataegus nananixonii	Nixon's dwarf hawthorn	Plants	Yes	Not Listed	Not Listed	G1	S1	Yes	Found in open upland post oak-bluejack oak, scrubby woodland, or shortleaf pine-oak woodland on the Carrizo Sands and other formations.
Crataegus turnerorum	Turner's hawthorn	Plants	Yes	Not Listed	Not Listed	G3	S3	Yes	Brush, dwarf oak scrub, stream banks, 300-600 m elevation; Perennial; Flowering April-June; Fruiting April-Sept
Crataegus viridis var. glabriuscula	green hawthorn	Plants	Yes	Not Listed	Not Listed	G5T3T4	S3	No	In mesic soils of woods or on edge of woods, treeline/fenceline, or thicket. Above\near creeks and draws, in river bottoms. Flowering Mar-Apr; fruiting May-Oct.
Croton alabamensis var. texensis	Texabama croton	Plants	Yes	Not Listed	Not Listed	G3T2	S2	Yes	In duff-covered loamy clay soils on rocky slopes in forested, mesic limestone canyons; locally abundant on deeper soils on small terraces in canyon bottoms, often forming large colonies and dominating the shrub layer; scattered individuals are occasionally on sunny margins of such forests; also found in contrasting habitat of deep, friable soils of limestone uplands, mostly in the shade of evergreen woodland mottes; flowering late February-March; fruit maturing and dehiscing by early June
Croton coryi	Cory's croton	Plants	Yes	Not Listed	Not Listed	G3	S3	Yes	Grasslands and woodland openings on barrier islands and coastal sands of South Texas, inland on South Texas Sand Sheet; Annual; Flowering July-Oct; Fruiting July-Nov
Croton pottsii var. thermophilus	leatherweed croton	Plants	Yes	Not Listed	Not Listed	G5T1	S1	No	Sparingly vegetated desert grasslands on extremely xeric sites at low elevations (500-800 m [1650-2640 ft), on substrates ranging from sand to limestone and basalt; flowering spring-fall
Croton suaveolens	scented croton	Plants	Yes	Not Listed	Not Listed	G3	S2	No	Grasslands at middle elevations in mountains; Perennial; Flowering April-Nov; Fruiting June-Nov
Cryptantha paysonii	Payson's hiddenflower	Plants	Yes	Not Listed	Not Listed	G3	S1	No	Rocky limestone slopes in mountains; Perennial; Flowering May; Fruiting May-June
Cuscuta attenuata	marsh-elder dodder	Plants	Yes	Not Listed	Not Listed	G1G3	S2	No	Parasitizes a particular sumpweed (Iva annua) almost exclusively as well as ragweed and heath aster. Host plants typically found in open, disturbed habitats like fallow fields and creek bottomlands; Annual; Flowering late summer through October
Cuscuta exaltata	tree dodder	Plants	Yes	Not Listed	Not Listed	G3	S3	No	Parasitic on various Quercus, Juglans, Rhus, Vitis, Ulmus, and Diospyros species as well as Acacia berlandieri and other woody plants; Annual; Flowering May-Oct; Fruiting July-Oct
Cyperus cephalanthus	giant sharpstem umbrella-sedge	Plants	Yes	Not Listed	Not Listed	G3?Q	S1	No	In Texas on saturated, fine sandy loam soils, along nearly level fringes of deep prairie depressions; also in depressional area within coastal prairie remnant on heavy black clay; in Louisiana, most sites are coastal prairie on poorly drained sites, some on slightly elevated areas surrounded by standing shallow water, and on moderately drained sites; soils include very strongly acid to moderately alkaline silt loams and silty clay loams; flowering/fruiting May-June, August-September, and possibly other times in response to rainfall
Cyperus grayoides	Mohlenbrock's sedge	Plants	Yes	Not Listed	Not Listed	G3G4	S3S4	No	Deep sand and sandy loam in dry, almost barren openings in upland longleaf pine savannas, mixed pine-oak forests, and post oak woodlands; Occurs primarily in deep, periodically disturbed sandy soils in open areas maintained by factors such as wind, erosion, or fire. This species does not occur in shaded areas or in areas of high competition with other herbaceous species. Habitats include remnant sand prairies, sandy fields, sand blow outs, sandhill woodlands, pine barrens, and open barrens in which the slope is sufficient to produce sand erosion. May also occur in areas where the soils have been disturbed by logging or road construction; Perennial
Cyperus onerosus	dune umbrella-sedge	Plants	Yes	Not Listed	T 03/30/2020	G2	S2	Yes	Moist to wet sand in swales and other depressions among active or partially stabilized sand dunes; flowering/fruiting late summer-fall
Cypripedium kentuckiense	Southern lady's-slipper	Plants	Yes	Not Listed	Not Listed	G3	S1	No	Primarily restricted to calciphilic hardwood slope forests, mesic ravines, hardwood terraces above floodplains, and seepage slopes; flowering late March-May