(DRAFT) - Taxonomy
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
TAXONOMY
NAME - DOGWEED, ASHY
OTHER COMMON NAMES - DOGWEED and ASHY
ELEMENT CODE -
CATEGORY - Angiosperm
PHYLUM AND SUBPHYLUM - MAGNOLIOPHYTA,
CLASS AND SUBCLASS - MAGNOLIOPSIDA,
ORDER AND SUBORDER - ASTERALES,
FAMILY AND SUBFAMILY - ASTERACEAE,
GENUS AND SUBGENUS - DYSSODIA,
SPECIES AND SSP - TEPHROLEUCA,
SCIENTIFIC NAME - DYSSODIA TEPHROLEUCA
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Ashy Dogweed
Dyssodia tephroleuca Blake
KINGDOM: Plant GROUP: Angiosperm
DIVISION: Magnoliophyta CLASS: Magnoliopsida
ORDER: Asterales FAMILY: Asteraceae
Perennial herb to 30 cm tall, spreading, woody near the base,
covered with soft ashy-white wooly hairs; leaves alternate, linear,
entire or somewhat trifid at the apex, 10-15 mm long, 0.3-0.8 mm wide,
with glands hidden in the pubescence; peduncles 1-3 cm long, with 0-3
foliaceous bracts; calyculum of 3-4 linear bracts about half as long
as the phyllaries, with a gland near the base and often a second near
the middle, wooly beneath, almost glabrous above; involucre
campanulate, 5-10 mm high, 8 mm across, white-wooly; phyllaries
12-13, joined about three-quarters of their length, apex triangular,
1.5-2 mm long, with glands in the upper half to third; receptacle flat
convex to nearly hemispheric, naked or with a few fine bristles; ray
florets 10-15, bright golden yellow, tube about 2 mm long, lamina
oblong-oval, 6-8 mm long, 3-4 mm wide, with 2-3 teeth at tip; disc-
florets 30-70, yellow, 4.5-5 mm long, funnelform, lobes ovate to
triangular, erect; style branches with deltoid, hispidulous, cuspidate
Taxonomy - 1 (DRAFT) - Taxonomy
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
appendages; pappus of 10-11 subequal scales, about as long as disc
floret, each scale with a central awn and 2-4 shorter lateral ones;
achene cylindric-clavate, 2-4 mm long, black, striate, sparsely
pubescent; n=8 (01,02,03).
Dyssodia tephroleuca was described by Dr. S.F. Blake in 1935
(04). Dr. John Strother monographed the genus Dyssodia for his Ph.D.
dissertation in 1967, and placed D. tephroleuca in the subgenus
Hymenatherum section Gnaphalopsis, partially based on chromatographic
work (05). Fifteen years later Strother divided Dyssodia into several
genera because these genera were more closely allied with other genera
in the Tageteae than Dyssodia (06). The ashy dogweed is now
Thymophylla tephroleuca (Blake) Strother (06).
The holotype of Dyssodia tephroleuca is housed at the U.S.
National Herbarium with an isotype at the University of Michigan
Herbarium (02,03,04,05,07). No illustrations are currently available.
Taxonomy - 2 (DRAFT) - Status
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
STATUS
Coded Status
E: Federal Endangered
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The ashy dogweed (Dyssodia tephroleuca) has been designated an
Endangered species pursuant to the Endangered Species Act
of 1973 (50 CFR 17.12; P.L. 93-205, 87 Stat. 884; 16 U.S.C.
1531-1540), as amended. The species has this status wherever found
including the State of Texas.
This species is protected by the Lacey Act (P.L. 97-79,
as amended; 16 U.S.C. 3371 et seq.) which makes it unlawful
to possess any wild plant (including roots, seeds, and other
parts) within U.S. territorial or special maritime jurisdiction
(as defined in 18 U.S.C. 7); or to import, export, transport, sell,
receive, acquire, or purchase in interstate or foreign commerce any
wild plant (including roots, seeds, and other parts) taken, possessed,
transported, or sold in violation of any State law or regulation. It
is also unlawful to import, export, transport, sell, receive, acquire,
or purchase any wild plant (including roots, seeds, and other parts)
taken or possessed in violation of any U.S. law, treaty, or regulation
or in violation of Indian tribal law.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
STATE: Texas
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: Texas Parks and Wildlife Department
STATE STATUTE: Chapter 88 of the Texas Parks and Wildl. Code,
Sections 57.401-57.413
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
None.
ECONOMIC STATUSES:
Status - 1 (DRAFT) - Status
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
The species has value as a component of Texas' natural heritage
of biotic diversity.
75/07/01:40 FR 27823/27924 - Notice of Review
76/06/16:41 FR 24523/24572 - Proposed Rule
79/12/10:44 FR 70796/70797 - Withdrawl of Proposed Rule
80/12/15:45 FR 82480/82569 - Revised List of Plants Under Review
83/07/22:48 FR 33501/33503 - Proposed Rule
84/07/19:49 FR 29232/29234 - Final Rule - Listed as Endangered
85/09/27:50 FR 39526/39527 - Notice of review
Status - 2 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
LAND USE -
Transportation, communications, and Util
Cropland and Pasture
Mixed Rangeland
COMMENTS ON HABITAT ASSOCIATIONS -
The ashy dogweed occurs on mixed rangeland commonly used for
grazing in the Texas savanna. This region is also known as the South
Texas Plains (08) or the ceniza-blackbrush-creosote bush brush (09).
Turner speculated that the area may have originally been a grassland
(03).
According to Turner, the ashy dogweed grows in open areas of fine
sandy-loam (03). Although the soils of Zapata County have not been
finely mapped, the general soil map shows the site to be on the
Maverick-Catarina soils association (10).
Such soils are clayey, saline, deep to shallow, fine textured and
slowly permeable (10). The ashy dogweed occurs on the Laredo
Formation (Eocene sandstones and clays) (11).
The ashy dogweed grows on an extremely gentle south-facing slope.
The elevation varies from 400 to 415 feet (01).
The climate is hot, semi-arid, and suffers from droughts.
Average annual precipitation is about 20 inches with peaks in
September and May to June (12). The temperature averages 73 degrees F
annually (13).
The known population of ashy dogweed grows along a two-lane U.S.
highway and extends into the adjacent pasture on both sides of the
road (01). The plants also occur along the fenceline and near a
culvert (01).
Habitat Associations - 1 (DRAFT) - Food Habits
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
AUTOTROPH
Food Habits - 1 (DRAFT) - Environment Associations
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G
G Availability of fence rows: roadside ditches and grassy
G
G
G
Environment Associations - 1 (DRAFT) - Life History
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
LIFE HISTORY
HABIT:
The ashy dogweed is an herb (01,02,03,04,05,07).
LIFE CYCLE:
Perennial (01,02,03,04,05,07,08).
TYPE OF REPRODUCTION:
The type of reproduction in the ashy dogweed is not known, but is
assumed to be sexual.
REPRODUCTIVE PHENOLOGY:
The phenology of this species is unknown, but flowering is
believed to occur probably anytime, especially after rains (03).
SEX OR SPORE STATUS:
Monoecious (01,02,03,04,05,07).
POLLINATION, SPORE AND SEED DISSEMINATION:
Unknown.
SEED BIOLOGY:
Unknown.
POPULATION BIOLOGY:
In his status report, Dr. B.L. Turner stated that the population
consisted of about 35 plants along or near the fenceline (03). He
returned to the site with Dr. Alan Zimmerman on November 15, 1980, and
counted almost 900 plants (14). About 500 of these were within a
pasture east of Highway 83 (14). Poole visited the locality in the
fall of 1985, and found approximately 250 individuals primarily
between the highway and the fenceline on either side of the road (01).
Although the area east of the highway was not surveyed directly, the
pasture appeared to have been recently cleared of brush and planted to
buffelgrass (01).
ECOLOGICAL/EDAPHIC FACTORS:
The ashy dogweed grows in full sunlight on xeric, finely textured
soils (01). Although Turner characterized the soils as a fine sandy-
loam (03), the general soil map of Zapata County shows the area as
being of the Maverick-Catarina soils association (10). Such soils are
clayey, saline, deep to shallow, fine textured and slowly permeable
(10).
The underlying geologic formation in the area is the Laredo
Formation, composed of sandstones and clays from the Eocene (11). The
population grows on an extremely gentle south-facing slope, at
elevations between 400 to 415 feet (01).
The climate is hot, semi-arid, and prone to droughts. Average
annual temperature is 73 degrees F (13). Precipitation averages about
20 inches annually, with a peak in August-October, in particular
September, and a lesser peak in May-June (12).
Life History - 1 (DRAFT) - Life History
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
TROPHIC STATUS:
Phototrophic (01,02,03,04,05,07).
CHARACTERISTIC DOMINANCE:
Component (01,03).
COMMUNITY ECOLOGY:
The ashy dogweed is a member of the ceniza-blackbrush-
creosotebush brush community (09). Although Turner commented that the
site may have been a grassland originally (03), the site has been, and
will remain, a brushland.
SPECIES INTERRELATIONSHIPS:
None.
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 2 (DRAFT) - Management Practices
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Restricting/regulating human disturbance of populations
Beneficial Controlling/Restricting Road Maintainance Actions
Beneficial Land Acquisition
Beneficial Controlling/Restricting Herbicide Use
Beneficial Controlling/Restricting Agricultural Practice
Beneficial Controlling/Removing Nonnative Vegetation
Beneficial Stocking captive-reared wild-strain animals
Beneficial Transplanting wild animals
Beneficial Transplanting Wild Eggs/Wild Seeds
Beneficial Controlling/Removing Domestic Animals
Adverse Collecting
Existing Collecting
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Highway/Railroads
Existing Highway/Railroads
Adverse Soil compaction by heavy equipment in mine areas
Existing Soil compaction by heavy equipment in mine areas
Adverse Applying herbicides
Existing Applying herbicides
Adverse Competition
Existing Competition
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Erosion
Existing Erosion
Adverse Grazing
Existing Grazing
Adverse
Existing
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
COMMENTS ON MANAGEMENT PRACTICES -
Habitat destruction and alteration has had the most impact on
the ashy dogweed. The management practices of the ranching industry
and the Texas Highway Department have destroyed or altered the habitat
of the ashy dogweed (01).
A common range management technique in the ashy dogweed's habitat
is to clear the land of brush (01). Usually after the clearing, the
area is reseeded (01). The exotic, highly competitive buffelgrass is
most often used in the Rio Grande Plains (01). Bufflegrass forms
dense stands and easily shades out the lower-growing ashy dogweed
(01). Although cattle probably do not eat ashy dogweed, soil
compaction and trampling from grazing hinder seedling establishment
(01).
A major part of the population occurs on the highway right-of-way
(01,03). The right-of-way has been bladed level with the pavement
Management Practices - 1 (DRAFT) - Management Practices
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
(01). The ashy dogweeds are currently hanging off the one to two foot
edge of the dirt curb, and some of the plants appear to be dying (01).
Herbicides appear to have been used around a culvert within the ashy
dogweed site (01). Probably the development of the highway extirpated
many individuals, and widening would threaten many more (01).
A pipeline passes through the population (01). Probably many
plants were killed by heavy equipment during its construction (01).
All collections of the ashy dogweed, except one, have been made
from the one population (01). This may have put some stress on the
species (01).
With only one population site and less than 1000 individuals, the
species suffers from a small gene pool (01). Any number of natural
factors could lead to its extinction (01). No seedlings or immature
plants have been recorded (01).
Future threats would include widening of the highway and pipeline
maintenance.
UNAPPROVED PLAN:
U.S. Fish and Wildlife Service. 1986. Recovery Plan for the Ashy
Dogweed (Dyssodia tephroleuca). Tech./Agency Draft. U.S. Fish and
Wildl. Serv., Albuquerque, NM. 33 pp.
The final approved recovery plan is scheduled for completion on
September 30, 1987.
The prime objective of the recovery plan is to manage and protect
the essential habitat of ashy dogweed so that healthy populations can
be sustained in their natural habitat. The first step in this process
is to protect existing plants and habitat by:
1. identifying essential habitat required for the species continued
existence,
2. working with landowners of essential habitat to make them aware of
the plants and habitat and helping them to manage their land to the
benefit of the species,
3. obtaining permanent protection (i.e., land acquistion) of plants
at the known site,
4. erecting and maintaining fences around the protected site (to limit
human access and to prevent damage from grazing),
5. developing a management plan, and
6. monitoring the known populations.
Habitat requirements of ashy dogweed should be identified,
including: (1) edaphic factors (i.e., soil characteristics), (2) local
microclimate, (3) air and water quality requirements, (4)
physiographic and topographic characteristics, (5) vegetation
physiognomy and community structure, (6) frequently associated
species, (7) dominance and frequency, (8) successional phenomena, and
(9) dependence on natural disturbance. The demography and phenology
of the species should be studied. The reproductive biology must also
be investigated. Factors that need to be understood include: (1)
types of reproduction, (2) pollination biology, (3) seed dispersal,
(4) seed biology, (5) seedling ecology, and (6) survival and mortality
Management Practices - 2 (DRAFT) - Management Practices
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
factors. Population ecology studies should investigate positive,
negative, and neutral interactions and hybridizations. There should
be continued searches for additional populations. The recovery of
the species may be helped by the establishment of additional
populations in suitable natural habitats and in cultivation. This
will require the development of effective cultivation techniques, the
maintenance of populations in botanical gardens, and searches for
suitable natural habitat for transplants. Public awareness and
support for the preservation of ashy dogweed must be encouraged.
Management Practices - 3 (DRAFT) - References
Species DOGWEED, ASHY
Species Id ESIS702030
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 U.S. Fish and Wildlife Service. 1986. Recovery plan for the Ashy
dogweed. Tech. Rev. Draft. U.S. Fish and Wildl. Serv.,
Albuquerque, NM. 30 pp.
02 Strother, J.L. 1969. Systematics of Dyssodia (Compositae:
Tageteae). Univ. Calif. Publ. Bot. 48:1-87.
03 Turner, B.L. 1980. Status report on Dyssodia tephroleuca Blake.
U.S. Fish and Wildl. Serv., Albuquerque, NM.
04 Blake, S.F. 1935. New Asteraceae from the United States, Mexico,
and South America. Journ. Wash. Acad. Sci. 25:311-325.
05 Strother, J.L. 1967. Systematics of Dyssodia (Compositae:
Tageteae). Ph.D. Diss., Univ. of Texas, Austin.
06 Strother, J.L. 1986. Renovation of Dyssodia (Compositae:
Tageteae). Sida 11:371-378.
07 Correll, D.S., and M.C. Johnston. 1970. Manual of vascular plants
of Texas. Texas Res. Foundation, Renner.
08 Gould, F.W. 1975. Texas plants - a checklist and ecological
summary. Texas A&M Univ., College Station.
09 McMahan, C.A., et al. 1984. The vegetation types of Texas. Texas
Parks and Wildl. Dept., Austin.
10 Soil Conservation Service. 1971. General soil map, Zapata County.
U.S. Dept. of Agri., Wash., D.C.
11 Bureau of Economic Geology. 1976. Geologic atlas of Texas:
Laredo sheet. Univ. of Texas, Austin.
12 Bomar, G.W. 1983. Texas weather. Univ. of Texas Press, Austin.
13 Larkin, T.J., and G.W. Bomar. 1983. Climatic atlas of Texas.
Texas Dept. of Water Res., Austin.
14 Turner, B.L. 1980. Update to status report on Dyssodia
tephroleuca Blake. U.S. Fish and Wildl. Serv., Albuquerque, NM.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Turner, B.L. 1980. Status report on Dyssodia tephroleuca Blake.
U.S. Fish and Wildl. Serv., Albuquerque, NM.
02 Gonzales, S. 1986. Pers. comm.
03 Strother, J.L. 1967. Systematics of Dyssodia (Compositae:
Tageteae). Ph.D. Dissertation, Univ. of Texas at Austin.
04 Cox, P.W. 1986. Pers. comm.
05 Everitt, J. 1986. Pers. comm. USDA, Weslaco, TX.
06 Blake, S.F. 1935. New Asteraceae from the United States, Mexico,
and South America. Journ. Wash. Acad. Sci. 25:311-325.
References - 1