Polyctenium fremontii var. fremontii

Polyctenium williamsiae Rollins:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Polyctenium fremontii (S. Watson) Greene:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Type of Residency: Year-round

Global Range: Endemic to the Blue Mountains of Oregon (Kartesz, discussion, 15Mar98). Reports from Nevada made between 1997 and 1999 were false, based on a misidentification (Jim Morefield, pers. comm. March 2000).

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

POLYCTENIUM FREMONTII is the only other member of the genus and differs from P. WILLIAMSIAE in having taller stems, 5-15 cm long; linear, elongate siliques 6-13 mm long and 1-1.5 mm wide; larger flowers with petals 5-6 mm long; styles up to 1 mm long, and greyish instead of greenish herbage (Rollins 1938). POLYCTENIUM FREMONTII is most abundant in eastern Oregon (Rollins 1992) and also occurs in parts of southern Idaho, eastern California, and northern Nevada (Davis 1952, Hitchcock & Cronquist 1973, Munz 1968). POLYCTENIUM FREMONTII is not found with P. WILLIAMSIAE but occurs in similar habitat as well as in rocky washes and seeps.

In describing POLYCTENIUM as a new genus, Greene (1912) intuitively separated it from SMELOWSKIA on the superficial basis of herbage texture, and recognized three species, P. BISULCATUM, P. FREMONTII, and P. GLABELLUM. Rollins (1938) lumped the group together into a single species consisting of two varieties, P. FREMONTII VAR. BISULCATUM and P. FREMONTII VAR. FREMONTII. Variety BISULCATUM is known only from the type collection in the Silvies Valley, Oregon and differs from VAR. FREMONTII in being densely pubescent and having flat, somewhat bisulcate pods. Rollins further clarified many differences between the two related genera POLYCTENIUM and SMELOWSKIA. In summary, POLYCTENIUM is a low elevation intermountain genus, with an absence of whitish pubescence, and has non-petiolate, highly dissected leaves, while SMELOWSKIA is an arctic-alpine genus extending from Alaska to southern portions of the Rocky Mountains and Cascade Range, and eastern Nevada, with a dense whitish tomentum, and petiolate, often lobed leaves (Rollins 1938). Munz (1968) distinguished POLYCTENIUM and SMELOWSKIA primarily by fruit type, the former with siliques and the latter with turgid silicles.

POLYCTENIUM belongs to a large group of closely related genera. Velichkin (1979) determined the extent of the genus SMELOWSKIA using a complex of anatomical and morphological characters, he then pointed out affinities and differences of these characters, which were often confused, to the genera HEDINIA, SOPHIOPSIS, CAPSELLA, HUTCHINSIA, AND POLYCTENIUM. Distribution data from this group suggested that SMELOWSKIA was the oldest and originated in the mountains of Asia.

Comments: POLYCTENIUM WILLIAMSIAE is found along the outer margins of four undrained depressions (locally known as the dry lakes) (BLM 1986) that are covered with shallow water during periods of runoff, however, the lakes may persist for extended periods following wet winters. These intermittent lakes are within ¼ to ½ mile of each other at elevations between 5,670 and 5,760 feet in the Virginia Range, Washoe County, Nevada. Sagebrush steppe with some scattered Utah juniper covers the surrounding slopes and ridges.

All the lakes are separated from each other by low ridges and have unique closed watersheds. The largest drainage of approximately 1200 acres feeds an oblong-shaped basin formed along a north-south trending fault easily seen on aerial photographs (Bell 1980, Slemmons 1972). The waterline in this basin encompasses a lake surface area ranging from 12 acres (½ ft. deep) to 106 acres (3 ft. deep). The other three lakes have minimum surface areas of between 2 and 4 acres with a combined watershed area of about 500 acres.

In the western United States fault activity is a common cause of intermittent pool topography (Norwick 1991). Bonham (1992) points out that many similar fault-bounded basins occur to the north in the Virginia Range. These can be easily identified on the geologic map of the Vista quadrangle as recent landforms of only a couple million years old. These areas are generally between 4,500 and 6,000 feet in elevation, bounded by north-south trending faults, and associated with quaternary age lacustrine sediments.

The peaks and ridges surrounding the basins are part of the Kate Peak Formation and consist of a thick sequence of tertiary volcanic rocks composed of flows, conglomerates, and tuff breccias consisting of andesite, dacite, and rhyolite (Bonham, 1969). Weathering of these volcanic rocks has produced fine-grained, poorly drained clay soils resulting in hardpan formation on the basin floors.

Soil surveys of the area classify the bottoms of the dry lake beds as playas and describe them as consisting of very deep, somewhat poorly drained and moderately well drained soils in nearly level undrained basins (Baumer 1979). The soil materials are mostly clay, silty clay, and silty clay loam often forming dense surface crusts. RUMEX LACUSTRIS and POLYGONUM AVICULARE, plants commonly of alkaline situations, cover the lake bottoms, however the former is restricted to the largest lake which receives a greater amount of water.

POLYCTENIUM WILLIAMSIAE is found mostly within the Sagouspe Variant soil series which extends from the outer edge of the lakebeds to the extreme high water line associated with dead sagebrush. The Sagouspe Variant consists of very deep, poorly drained soils on flood plains and lake terraces mostly derived from alluvium. The soil profile is more than 60 inches thick and characterized by a loose surface layer of very fine loamy sand 5 inches thick. The upper 17 inches of the underlying material is sand. The lower part, to a depth of 60 inches, is stratified sand and silt loam. Clay or silty clay is the underlying material. Effective rooting depth is 60 inches for water tolerant plants but is limited to 20 to 36 inches (the seasonal high water table depth) for water sensitive plants. Reaction throughout the profile ranges from slightly acid to neutral (Baumer 1979).

The lakes periodically fill with water following intense periods of rain or runoff from melting snow. One unusual event in February 1986 resulted in a maximum high water level that drowned a band of mature sagebrush (Wolfe 1992). Between 1969 and 1991 average annual precipitation was 23.2 inches at Fort Franktown, a weather station seven miles southwest of the lakes basin at 5,250 feet. In this period a maximum of 47.1 inches was recorded in 1982 and a minimum of 10.1 inches in 1988. For the month of February 1986, 21.1 inches of rain fell at the station. Klieforth (1992) notes that in 1986 a weather pattern developed that produced precipitation amounts in western Nevada equal to that of the western slope of the Sierra Nevada, ie. very little rain shadow effect. Thus, climate data from the Fort Franktown site in 1986 can be used to calculate water levels in the lakes basin.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 1 - 5

All the specimens of P. FREMONTII deposited in the University of Nevada Reno herbarium were collected between early May and late June. Plants collected in early May had flower buds in the upper axils and immature fruits at the base of the inflorescence, while late June plants had well-developed fruits in the lower axils and a few flowers toward the stem apex. Collections of P. WILLIAMSIAE from early June to early July generally match the phenology seen in P. fremontii. During a visit to the dry lakes in mid July Knight (1990) observed the majority of plants were fruiting, with only a few flowers blooming at the tips of inflorescences. In early March, 1992 P. WILLIAMSIAE was already emerging with tufts of new leaves. It is likely that the flowering period of P. WILLIAMSIAE starts in early May.

During a recent reconnaissance trip to the area two additional populations of P. WILLIAMSIAE were discovered at sites that had been previously searched but no plants found. These new occurrences were found along the margins of two dried lakes of similar physiography a short distance from the other lakes. Nachlinger and Heise (1992) made a conservative estimate of 1-3 plants per square meter or 1,000 individuals at each site, noting an even distribution of plants around the margin of the lakes.

Knight (1990) made a total population estimate of 3,000 - 5,000 plants in July 1990, noting only 32 individuals at the west end of the largest lake versus several thousand at the east end. She states, "The difference in topography between the two shore lines may account for this numerical anomaly" (Knight, 1990). In addition, Knight (1992a) noted that the population appeared more sporadic in 1990 than it did in 1988.

Year-to-year fluctuations in precipitation provide a highly variable water regime to intermittent pools with resulting annual shifts in the water table that ultimately effect plant distribution (Holland and Jain 1977). In 1983 P. WILLIAMSIAE was observed growing below the lower most band of big sagebrush, which was alive at the time, surrounding the two lakebeds where it was discovered (Tiehm 1983), while Knight (1992a) noted the plants higher up within the dead sagebrush zone a couple years after the heavy rains of 1986. Recent observations indicate that P. WILLIAMSIAE has shifted downward again toward the lake bottoms as a result of a lowering water table and is more common just below the dead sagebrush zone (Nachlinger and Heise 1992). Tiehm (1992) has observed large populations of P. FREMONTII that have completely disappeared the following year after an unusually wet winter, suggesting that P. FREMONTII is probably a water sensitive plant, surviving only as a rootstock or seed when conditions are too wet to grow. This intermittent growth may be responsible for P. WILLIAMSIAE going undiscovered in two nearby pools of similar physiography in the Virginia Range and several others to the south in the Pine Nut Range.

Currently, P. WILLIAMSIAE is found along a zone 10-100 feet wide between the wetter soils supporting POLYGONUM AVICULARIE and the inner edge of the drowned sagebrush. At all sites P. WILLIAMSIAE is strongly associated with MUHLENBERGIA RICHARDSONIS, a dense mat-forming perennial considered an important forage grass and good soil binder (Cronquist, et al. 1977). Other associated species include CAREX DOUGLASII, JUNCUS BALTICUS, CAMISSONIA TANACETIFOLIA, and POTENTILLA NEWBERRYI. POLYCTENIUM WILLIAMSIAE is most common on patches of ground lacking other species and infrequent where C. DOUGLASII forms a nearly continuous mat.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1

Rounded Global Status Rank: T4 - Apparently Secure

Rounded Global Status Rank: T2 - Imperiled

Rounded Global Status Rank: G4 - Apparently Secure

United States

Rounded National Status Rank: N2 - Imperiled

Rounded Global Status Rank: G2 - Imperiled

Reasons: Considered in the strict sense, this taxon is endemic to Nevada. However, it may not be distinct from P. fremontii var. confertum (which would become a synonym), a taxon that is known from 1 large population (about 420,000 plants) in eastern California. There are 23 much smaller Nevada populations that could be assigned to either taxon. Considering the 2 taxa together, the 24 known sites have a total of about 425,000 plants. The plants are restricted to the margins of lakes and ponds and water development has been documented to have impacted 1 site and is considered a threat to most others. Off-road vehicles and grazing by livestock and wildlife have also impacted several sites.

United States

Rounded National Status Rank: N4 - Apparently Secure

United States

Rounded National Status Rank: N2 - Imperiled

United States

Rounded National Status Rank: NH - Possibly Extirpated

Rounded Global Status Rank: TH - Possibly Extinct

Reasons: Known only from the Blue Mountains of Oregon, where not recently seen, according to John Kartesz (North Carolina Botanical Garden). No information from Oregon Heritage on this variety. Nevada Heritage reports that reports of this variety are false due to misidentification. Considered an extinct endemic of Oregon by Kartesz in 1999 Floristic Synthesis.

United States

Rounded National Status Rank: N4 - Apparently Secure

Comments: It is not known to what extent livestock grazing has affected the population status of POLYCTENIUM WILLIAMSIAE. A case history study (Bureau of Land Management, (BLM) 1988) for the Jumbo allotment dates the first use of cattle back to 1929, but it is likely that sheep grazed the area beginning as early as 1860 (Short 1965). Currently, 87 cattle utilize the allotment between May 1 and August 31 and 5,860 sheep between May 1 and June 30. The present livestock forage allocation is 1,998 animal unit months (AUM) (an animal unit month is the forage required to sustain one cow or its equivalent for a period of 1 month) (Raffetto 1992). Grazing use appears to be heavy following wet winters. During a "range readiness ride" in early April, 1986, Cub Wolfe noted that the dry lakes had plenty of water and range conditions were two weeks behind that of the lower canyon. In late August of the same year he observed heavy grazing use around the lakes (BLM 1986).

The Jumbo allotment is classified into a "C" (Custodial) category as part of the Rangeland Management Program (RMP), which receives the lowest priority for funding range improvements. Trend studies based on range utilization maps have shown a downward movement for the Jumbo allotment indicating a deteriorating range condition. However, the present RMP implementation is to maintain present grazing practices on the allotment (BLM 1982, BLM 1989, Raffetto 1992). Both Ramakka (1992) and Raffetto (1992) agree that evaluation procedures should begin to change the Jumbo allotment classification from "C" to "M" (Maintain) based on the fact that P. WILLIAMSIAE is a category 1 candidate for federal listing (Federal 1990).

Wolfe (1992) remarks that sheep probably pose more of a threat to P. WILLIAMSIAE than cattle do because of their higher numbers in the allotment and less discriminate eating habits. However, it is unlikely that P. WILLIAMSIAE is palatable to sheep. Kennedy and Doten (1901) report that even hungry sheep will not touch members of the mustard family.

Soils are shallow to moderately deep and well-drained and are susceptible to extensive erosion from over grazing, leading to an increase in runoff and sedimentation (Baumer 1979).

Off-road vehicles (ORV) pose a potential threat because of the easy access into the basin. Currently, the area is classified by the BLM as open to ORVs, but only slight use is evident around the lakebeds. There are no restrictions concerning ORV use other than a tacit obligation of responsible operator conduct. Knight (1992b), a BLM recreation planner, remarks that no monitoring of ORV traffic has been conducted in the area of interest.

A road along the east side of the largest lake runs directly through P. WILLIAMSIAE habitat. Any activity along the road or road improvements could substantially impact the population.

Part of the main drainage that feeds the largest lake passes through private land. Diverting water could exacerbate the effects of drought in lowering the basin's water table further. Knight (1992a) observed P. WILLIAMSIAE well up into the dead sagebrush zone in 1988, followed by several years of drought. In 1992 it has established itself mostly outside of the dead sagebrush zone (Nachlinger and Heise 1992) closer toward the lake centers where it could encounter severe competition with the annual POLYGONUM AVICULARE. Wolfe (1992) remarks that there is evidence of an old diversion ditch above the large lake, possibly an attempt by a past grazing permit holder to create additional watering areas for livestock.

As a result of the 1910 Public Water Reserve Act, a 40 acre parcel was put into a federal water reserve in 1955 (Huffnagel 1992). The closure ensures that no transfer of the land out of federal ownership can occur or any other activity take place with the exception of gold and silver mining. One of the small lakes is within the 40 acres of T17N, R20E, s16, NW¼, NE¼. The BLM Carson City District recommended the opening of this public water reserve during withdrawal review procedures in 1981 (Huffnagel 1992). At that time they were unaware of an occurrence of a rare and endangered plant.

The BLM has not received any proposals for potential site-disturbing activities near the intermittent lakes. A portion of an AT&T fiber optic transmission line is being relocated east of U.S. HWY 395 but runs no where near section 16 (Huffnagel 1992).

A number of introduced plant species occur with POLYCTENIUM WILLIAMSIAE but competitive relationships are unknown (Knight 1990).

Preserve Selection and Design Considerations: The 2.5 square miles of the four watersheds feeding the lakes deserve special consideration. Crucial habitat should be defined as an entire lake up to the highest water line as the distribution of P. WILLIAMSIAE appears to follow a widely fluctuating water table. If trampling becomes a concern, a crescent shape exclosure around the most dense area of the population would add a measure of protection and allow livestock access to water.

Management Requirements: Three of the lakes are located on BLM land within section 16 of Township 17 N, Range 20 E. A checkerboard ownership pattern has put the eastern most lake on private land within section 15 belonging to: Gloria Laborde, Overhill Lane, Davis, CA. 95616. Section 16 is part of the 15,389 acre Jumbo grazing allotment managed under the BLM Carson City District. Gloria Laborde also owns section 21 which lies south of section 16 and includes the principal road accessing the area, and part of the main drainage that feeds the largest lake.

Monitoring Programs: On the Jumbo allotment BLM monitoring studies in the lakes basin have typically focused on three key forage plant species, SITANION HYSTRIX, ORYZOPSIS HYMENOIDES, and STIPA THURBERIANA. These key plant species are the most important forage species on this part of the allotment and provide the bulk of the forage (Raffetto 1992). Range utilization is measured yearly on these key species and use pattern maps made to determine if use is too heavy or light to meet management objectives (Handbook 1984).

Actual use reports are written yearly by the allotment operators and reflect general livestock use patterns and range condition.

Two permanent sagebrush-grass photo plots were established in the allotment in 1968. A vertical view of a 3'X3'plot and an oblique view of the plot and surrounding vegetation were taken every 3-5 years. The technique was discontinued several years ago due to it's ineffectiveness to accurately monitor vegetation change (Raffetto 1992).

Biological Research Needs: Biosystematic studies are needed to ensure the status of P. WILLIAMSIAE as a unique genetic and morphological entity deserving protection and legal recognition.

Habitat requirements need to be studied. What is P. WILLIAMSIAE'S ecological and physiological optimum? Where is it establishing itself and where is it dying? Is it typically associated with severely disturbed areas opened up for invasion by cattle or sheep?. What are its tolerance ranges to sheep and cattle grazing, salt, and flooding? How extensive is P. WILLIAMSIAE'S seed bank in the lakes basin and what are its seed dormancy requirements? How are watershed hydrology dynamics and plant distribution related; most importantly, what is the climatic history of the area?

Life history characteristics are limited to generalities that P. WILLIAMSIAE is an herbaceous perennial. Details should be known on seed production and viability, conditions promoting germination, habitat requirements for seedling establishment, seral stage preferences, survivorship patterns, phenology, growth rates, pollinators, and seed dispersal vectors.

POLYCTENIUM WILLIAMSIAE is considered to be one of the rarest and most endangered species in Nevada because of its small population size, narrow geographical distribution, proximity to an urban area, and high disturbance potential (Tiehm 1992). The smaller the population, the more likely extinction is in any given period of time (Shaffer 1987). Therefore, knowledge of minimum viable population size and its area requirements would be valuable. How much larger than minimum viable size is best for effective management?

Can POLYCTENIUM FREMONTII be used as an appropriate model for P. WILLIAMSIAE in manipulative physiological studies, where large numbers of plants may have to be sacrificed?

Future inventory efforts should concentrate on nearby topographic features with similar geologic and hydrologic characteristics. Areas where negative searches were conducted (Knight 1990) should be resurveyed.

Stewardship Overview: POLYCTENIUM WILLIAMSIAE is a small herbaceous perennial in the mustard family that grows along the edges of four intermittent lakes in the Virginia Range in western Nevada. The population has persisted through periodic flooding and drought, and a long history of frequent disturbance from cattle and sheep grazing. Detailed studies in demography and physiological ecology that can document population trends and habitat requirements are needed to support decisions on its management.