Pecos Sunflower

Helianthus paradoxus

Description

The Pecos sunflower, also known as the puzzle sunflower, and as the paradox sunflower, is a tall, annual plant. It grows up to 4.3 to 6.5 ft (1.3-2 m) tall and is branched at the top. Its leaves are arranged in opposite fashion on the lower part of the stem, and alternate near the top. The leaves are lance-shaped, with three prominent veins, and are up to 6.9 in (17.5 cm) long and 3.3 in (8.5 cm) wide. The stem and leaf surfaces have a few short stiff hairs. The flower heads are 2-2.8 in (5-7 cm) in diameter, with bright-yellow ray florets and darker disk florets. The Pecos sunflower flowers from September to November.

Habitat

The Pecos sunflower inhabits desert wetlands. It grows in permanently saturated soils, such as desert wetlands (or cienegas) associated with springs, as well as the margins of streams and lakes. The soil is often saline and alkaline in character, although seeds of the Pecos sunflower germinate and establish best when a high water table reduces salinity near the surface. Associated plants include the Transpecos sea lavender (Limonium limbatum ), limewater brookweed (Samolus cuneatus ), Olney bulrush (Scirpus olneyi ), common reed (Phragmites australis ), alkali sacaton (Sporobolus airoides ), and alkali muhly (Muhlenbergia asperifolia ).

Distribution

The Pecos sunflower is known from 22 sites in Cibola, Valencia, Guadalupe, and Chaves Counties, New Mexico, and from three sites in Pecos and Reeves Counties, Texas.

Threats

The Pecos sunflower is threatened by various factors, particularly: the destruction or degradation of wetlands by filling; draining through diversion to provide water for livestock or irrigation; the construction of impoundments; the drying of its habitat through the depletion of local groundwater; excessive livestock grazing or mowing; the effects of local highway maintenance; and competition from non-native plant species (particularly saltcedar, Tamarix spp.). Compared with 200 years ago, the area of wetland in New Mexico has decreased by about 33% and that in Texas by 52%. In the late 1990s, the Pecos sunflower was known from 25 sites in five general areas. These areas are: Pecos and Reeves Counties, Texas; the vicinity of Fort Stockton and Balmorhea, Chaves County, New Mexico, from Dexter to just north of Roswell; Guadalupe County, New Mexico, near Santa Rosa; Valencia County, New Mexico, along the lower part of the Rio San Jose; and Cibola County, New Mexico, in the vicinity of Grants. There are three sites in the Fort Stockton-Balmorhea area, 11 in the Dexter to Roswell area, eight in the Santa Rosa area, one along the lower Rio San Jose, and two in the Grants area. Various federal, state, tribal, municipal, and private interests own and manage land containing habitat of the Pecos sunflower. Managing federal agencies include the U. S. Fish and Wildlife Service, Bureau of Land Management, and National Park Service. Plants are located in one New Mexico state park. Other populations are located on municipal property within the cities of Roswell and Santa Rosa, and the Laguna Indian Tribe owns and manages one site. Seven private individuals or organizations own sites or parts of sites. Some plants grow on state or federal highway rights-of-way. Most sites are less than 5 acres (2 hectares) in area, and some are only a fraction of a hectare. Two sites, one near Fort Stockton and one near Roswell, are considerably larger. The number of plants per site ranges from fewer than 100 to several hundred-thousand in the two largest sites. Because the Pecos sunflower is an annual plant, its abundance can vary greatly from year to year with changes in water conditions. However, if its wetland habitat dries out permanently, even a large population will soon disappear.

Conservation and Recovery

Five critical habitats of the Pecos sunflower are on property managed principally for wildlife and the conservation of endangered species. Two major sites are on Bitter Lake National Wildlife Refuge near Roswell, New Mexico, where there are six spring-fed impoundments totaling about 750 acres (300 hectares). These impoundments are managed with high water levels in winter, followed by a spring and summer drawdown that simulates a natural water regime. This management provides abundant habitat for the Pecos sunflower, allowing it to grow in dense stands at the edge of some impoundments. The Nature Conservancy of Texas owns and manages two sites, one near Fort Stockton, and the other near Balmorhea. Large, natural desert springs are the principal features of both preserves. The spring near Fort Stockton harbors a large population of the Pecos sunflower, which extends for about 0.75 mi (1.2 km) along the spring run. Two springs near Balmorhea owned by the Nature Conservancy sustain a population of several thousand Pecos sunflowers. Additional habitats of the rare sunflower should be protected, either by acquisition and establishment of ecological reserves, or by the negotiation of conservation easements. The abundance of the non-native saltcedar in its habitats should be reduced. Its populations should be monitored, and research undertaken to develop improved management practices.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
P.O. Box 1306
Albuquerque, New Mexico 87103-1306
Telephone: (505) 248-6911
Fax: (505) 248-6915
http://southwest.fws.gov/

U. S. Fish and Wildlife Service
New Mexico Ecological Services Field Office
2105 Osuna Road, N. E.
Albuquerque, New Mexico 87113-1001
Telephone: (505) 346-2525
Fax: (505) 346-2542

Reference

U. S. Fish and Wildlife Service. 20 October 1999. "Endangered and Threatened Wildlife and Plants: Determination of Threatened Status for the Plant Helianthus paradoxus (Pecos Sunflower)." Federal Register 64 (202):56581-56590.