(DRAFT) - Taxonomy
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
TAXONOMY
NAME - AGAVE, ARIZONA
OTHER COMMON NAMES - AGAVE, ARIZONA; AGAVE and NEW RIVER
ELEMENT CODE -
CATEGORY - Angiosperm
PHYLUM AND SUBPHYLUM - MAGNOLIOPHYTA,
CLASS AND SUBCLASS - LILIOPSIDA,
ORDER AND SUBORDER - LILIALES,
FAMILY AND SUBFAMILY - AGAVACEAE,
GENUS AND SUBGENUS - AGAVE,
SPECIES AND SSP - ARIZONICA,
SCIENTIFIC NAME - AGAVE ARIZONICA
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Arizona Agave
Agave arizonica Gentry & J.H. Weber
KINGDOM: Plant GROUP: Angiosperm
DIVISION: Magnoliophyta CLASS: Liliopsida
ORDER: Liliales FAMILY: Agavaceae
Small, acaulescent, single or cespitose rosettes ca. 30 cm high,
40 cm broad, with many leaves in a depressed globose form; mature
leaves mostly 17-24 by 2-4 cm, broadest in middle, linear-lanceolate,
acuminate, rigid fleshy, dark green, fibrous, smooth, the margin
1-2 mm wide, reddish-brown to light gray, continuous nearly to leaf
base; teeth variable, the larger 2-5 mm long, deflexed, to 1.5-2 cm
apart, terminal spine 1-2.5 cm long; inflorescence 3-4 m tall, slender
racemose-paniculate, very narrow with 35-40 very short lateral
branches; flowers small, 25-32 mm long, pale yellow, in clusters of
10-20; capsules 15-20 x 8-9 mm, elliptic to ovate, strongly beaked
(01).
The type specimen of Agave arizonica was collected by Weber
(S.N., U.S., A.S.U., DES.) as a live plant at the type locality
(New RIver Mountains, near the Maricopa - Yavapai County boundry,
AZ.). The species is known to have flowered at the Desert Botanical
Taxonomy - 1 (DRAFT) - Taxonomy
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
Garden, Accession No. 60-6628, Phoenix, AZ (08). Another common name
for the Arizona agave is the New River Agave as listed in CITES.
Taxonomy - 2 (DRAFT) - Status
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
STATUS
Coded Status
E: Federal Endangered
Commercial
Ornamental
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Arizona agave (Agave arizonica) 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 Arizona.
Removal and reduction to possession of any federally listed plant
from an area under Federal jurisdiction is unlawful (50 CFR 17.61 and
17.71).
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.
USFS -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Forest Service lands. The
Forest Service is responsible for integrating
management, protection, and conservation of Federally
listed species into the Forest Planning process
(36 CFR 219.19 and 219.20).
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),
Status - 1 (DRAFT) - Status
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
STATE: Arizona
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: Arizona Commission of Agriculture and
Horticulture.
STATE STATUTE: Arizona Native Plant Law (ARS Chapter 7, Section
3-901B)
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
Listed both in the IUCN Red Data Book (1978) and in Appendix I of
CITES, as endangered.
ECONOMIC STATUSES:
This species has horticultural value as an attractive garden
ornamental; its rarity makes it particularly desirable. It may be of
value for some of its yet undetermined phytochemical products and it
has value as a component of Arizona's natural heritage of biotic
diversity.
75/07/01:40 FR 27823/27824 - Notice of Review.
76/06/16:41 FR 24523/24572 - Proposed Rule, 1700 Species.
79/12/10:44 FR 70796/70798 - Withdrawal of Proposed Rule.
80/12/15:45 FR 82480/82481 - Notice of Continued Review.
83/05/20:48 FR 22757/22760 - Proposed Rule - List as Endangered.
84/05/18:49 FR 21055/21058 - Final Rule - Listed as Endangered.
86/05/02:51 FR 16363/16365 - Notice of Petition Finding.
Status - 2 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
LAND USE -
Shrub and Brush Rangeland
Mixed Rangeland
Bare Exposed Rock
COMMENTS ON HABITAT ASSOCIATIONS -
Agave arizonica has been found in Arizona chaparral and
juniper-grassland associations and in open range supporting cattle.
Associated plants are Agave chrysantha, A. toumeyana, Juniperus spp.,
Quercus turbinella, Cercocarpus montanus, Echinocereus fasciculatus
var. bonkerae, Yucca baccata, Nolina microcarpa, Ericameria
laricifolia, Opuntia phaeacantha, and Rhamnus crocea (03). Arizona
agave is found within the transition zone. The transition zone, is
where the Colorado Plateau, Mogollon Rim, Colorado Desert, and Arizona
Upland Desert converge (02,03).The potential distribution of
A. arizonica may include the MH2 Mapping Unit, a soil association
characterized by dark-colored, well-drained, shallow and very shallow,
gravelly and cobbly, moderately coarse to moderately fine-textured,
gently sloping to very steep soils and rock outcrops formed in the
residuum on igneous and sedimentary on hills and mountains. Average
annual precipitation is 250-375 (500) mm, 35-60% (1/6) of it occuring
in the winter months. The mean January and July air temperatures are
35-50 deg. F. and 70-85 deg., respectively. Average annual runoff is
2.5-5 cm. The mean annual soil temperature is 15-22 deg. Celsius.
Percent slope is mostly 20 to 50%, with a range of 10 to 70%. Soil
type is Lithic Torriorthents and Lithic Haplustolls (04). This
association is characterized by shallow, cobbly and gravelly,
strongly sloping to very steep soils and rock outcrop on mid-elevation
hills and mountains.
The agvae is found primarily on ridges (elevation 1097 to 1748
meters), although two clones have been located in drainages.
Other specific environmental parameters are not yet known.
Habitat Associations - 1 (DRAFT) - Food Habits
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
AUTOTROPH
Food Habits - 1 (DRAFT) - Environment Associations
Species AGAVE, ARIZONA
Species Id ESIS702026
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 Terrestrial Features: Rock outcrops
G
G
G
Environment Associations - 1 (DRAFT) - Life History
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
LIFE HISTORY
HABIT:
The Arizona agave is a succulent (01).
LIFE CYCLE:
Perennial (01).
TYPE OF REPRODUCTION:
Vegetative and possibly sexual (02,03).
REPRODUCTIVE PHENOLOGY:
Currently, only the fruiting date (August) and seed/fruit
dispersal date (August-November/December) are known for this species
(02).
SEX OR SPORE STATUS:
Monoclinous (05).
POLLINATION, SPORE AND SEED DISSEMINATION:
Pollen dissemination agents are unknown. The seed dissemination
agent are dehiscent capsule. (02)
SEED BIOLOGY:
Only two plants are known to have set seed, their viability is
unknown. One of the two flowered at the Desert Botanical Garden in
1967 but was most likely pollinated by any number of other species
of agaves which flowered at the same time. The second seed-setting
agave was recently discovered but its present endangered species
status has prevented subsequent research on its seed biology (02).
POPULATION BIOLOGY:
The Arizona agave is not known in a population, but as randomly
scattered individual plant clones within sympatic populations of two
other endemic agaves, A. chrysantha Peebles and A. toumeyana Trel.
ssp. bella (Breitung) Gentry (02).
ECOLOGICAL/EDAPHIC FACTORS:
Known Agave arizonica clones are within the TS6 Mapping Unit,
termed the Lithic Torriorthents-Lithic Haplustolls-Rock Outcrop
association. This association is characterized by shallow, cobbly
and gravelly, strongly sloping to very steep soils and rock outcrop
on mid-elevation hills and mountains. The soils are well-drained,
formed in residuum that is weathered from many rocks including
granite, gneiss, rhyolite andesite, tuffs, limestone, sandstone, and
basalt. Lithic torriorthents make up ca. 25% of the association with
Haplargids, other minor soils, and Torriflurents along drainageways
making up ca. 20%. Characteristics are further summarized: percent
slope, 20-50, range 10-70; elevation, 760-1760 m; mean annual
precipitation, 250-510 mm; winter precipitation as percent of the
annual, 35-60; mean January air temperature, 2-10 deg. C.; mean
July air temperature, 21-29 deg. C.; mean annual soil temperature,
15-22 deg C.; and frost free days, 160-260 (04).
Life History - 1 (DRAFT) - Life History
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
The potential distribution of A. arizonica may include the MH2
Mapping Unit, termed the Lithic-Haplustolls-Lithic Argiustolls-Rock
Outcrop association. This association is characterized by
dark-colored, well-drained, shallow and very shallow, gravelly and
cobbly, moderately coarse to moderately fine-textured, gently sloping
to very steep soils and rock outcrops formed in the residuum on
igneous and sedimentary on hills and mountains. Lithic Haplustolls
make up ca. 50% of the association, Lithic Arguistolls 20%, rock
outcrops 15%, and minor areas of other shallow, moderately deep and
deep soils 15%. Characteristics are further summarized: percent
slope, 5-60; elevation (central) 1370 m; mean annual precipitation,
410-630 mm; winter precipitation as a percent of annual, 30-60; mean
January temperature, 2-7 deg. C.; mean July air temperature, 21-29
deg. C.; mean annual soil temperature, 8-15 deg. C.; and frost free
days, 140-230.(04)
TROPHIC STATUS:
Phototrophic (01).
CHARACTERISTIC DOMINANCE:
Component (02,03).
COMMUNITY ECOLOGY:
Associated plants include: Agave chrysantha, A. toumeyana,
Juniperus spp., Quercus turbinella, Cercocarpus montanus, Echinocereus
fasciculatus, E. f. var. bonkerae, Yucca baccata, Nolina microcarpa,
Ericameria laricifolia, Opuntia phaeacantha, and Rhamnus crocea (03).
Its area of distribution represents an area of relative rapid
speciation as reflected in Agave spp. and Echinocereus spp.
populations. This area is called the transition zone, where the
Colorado Plateau, Mogollon Rim, Colorado Desert, and Arizona Upland
Desert converge (02,03).
SPECIES INTERRELATIONSHIPS:
None.
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 2 (DRAFT) - Management Practices
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Stocking captive-reared wild-strain animals
Beneficial Restricting Poaching
Beneficial Controlling/Restricting Noncommercial Harvest
Beneficial Regulating commercial harvest levels
Beneficial Controlling/Removing Native Vertebrates
Beneficial Controlling/Removing Domestic Animals
Adverse Inherent Reproductive Characteristics
Existing Inherent Reproductive Characteristics
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Hybridization
Existing Hybridization
Adverse Predation
Existing Predation
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Grazing
Existing Grazing
COMMENTS ON MANAGEMENT PRACTICES -
Agave arizonica is an extremely rare taxon. Little is known
of the reproductive biology of this agave; whether it can reproduce
sexually and successfully maintain a population is unknown. Out of 30
known clones, 13 plants were observed with their inflorescence broken
off by cattle using it as food. Only three agaves had fully
developed inflorescences. Cattle eating agave stalks is the greatest
known threat to sexual reproduction of the Arizona agave.(02)
Another threat to this species may be the Agave snout weevil
larvae that use agaves as host plants (07).
Findings strongly suggest that A. arizonica is a continually
occurring hybrid between A. chrysantha and A. toumeyana ssp. bella.
But many plant species are of hybrid origin. As Pinkava and Baker
(06) state, "Agaves apparently combine hybridity, polyploidy and
vegetative reproduction as their evolutionary strategy." A. arizonica
is the product of just such strategies. The putative parents are
each among the more highly advanced groups in their respective
subgenera. This suggests that polyploid populations are to be
found. Gentry (01) concludes that A. chrysantha "may be a geological
young species which has yet reached a stable or isolated condition...
it appears to be mixing genes with its neighbors and may even have its
own origins through introgression...." A. toumeyana ssp. bella itself
appears to indicate that speciation is active, as it shows distinction
from the typical species. By freely cloning and freely seeding, it
insures a long sexual generation and hence unlimited gene combinations
that will favor its ability to colonize new environments (02).
UNAPPROVED PLAN:
Management Practices - 1 (DRAFT) - Management Practices
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
No recovery actions will be taken pending the outcome of the
species' taxonomic evaluation. A technical draft recovery plan has
yet to be prepared on this species.
Information for this section was taken from the status report
by Phillips et. al. (1980) and the species file in the Region 2
office.
The primary threat to the survival of Agave arizonica is
collecting, since the plant is very decorative and makes an attractive
garden ornamental. Natural predation by deer (flowering stalks) and
rodents (young plants) could affect the numbers and reproductive
success of such a rare species. In addition, cattle graze flowering
stalks and could also affect plants through trampling and habitat
disturbance. Collecting should be restricted through enforcement of
the Endangered Species Act, CITES, Lacey Act and the Arizona Native
Plant Law (ARS 3-9018). The small known range of Arizona agave should
be periodically monitored to assess status of the populations and
adjacent areas should be searched for more populations. Designation
of Criticle Habitat should not be made since publication of exact
localities would jeopardize the species through illegal taking. It
may be necessary to prohibit taking of any Agave in the west-central
portion of Tonto National Forest in the range of A. arizonica due to
the difficulty in accurate identification of A. arizonica. Fencing
to protect remaining populations from grazing may need to be
considered. Propagation of this species from seeds and offsets of
plants already in cultivation should be encouraged. This might make
the species available for use as an ornamental and take collection
pressure off natural populations. Efforts to develop public
awareness, appreciation, and support for the preservation of the
Arizona agave are also needed.
The USFWS, with the assistance of Agave experts, evaluated a
petition for delisting of A. arizonica on the grounds that the taxon
is actually a hybrid and not a true species. The 365 day finding for
the petition to delist A. arizonica found that the delisting was not
warranted.
Management Practices - 2 (DRAFT) - References
Species AGAVE, ARIZONA
Species Id ESIS702026
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Gentry, H.S. 1982. Agaves of Continental America. Univ. AZ.
Press. Tucson.
02 DeLamater, Rick. 1986. Unpubl. rept. A preliminary status report
on Agave Arizonica. New River Stagecoach, Rte 1, Phoenix, AZ.
5 pp.
03 Hodgson, Wendy. 1986. Pers. knowledge. Phoenix, AZ.
04 Hendricks, David. 1985. Arizona Soils. Univ. of Ariz. Press,
Tucson.
05 Radford, A., et al. 1972. Vascular Plant Systematics. Harper
& Row, N.Y.
06 Pinkava, Donald, and Marc Baker. 1985. Chromosome and
hybridization studies of Agaves. Desert Plants. 7(2):93-100.
07 DeLamater, Rick. 1986. Pers. knowledge. Phoenix, AZ.
08 Phillips, B.G., A.M. Phillips, J. Mazzoni, and E.M. Peterson.
1980. Status report, Agave arizonica Gentry and Weber. On file
at: U.S. Fish and Wildl. Ser., Wash., D.C. 12 pp.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 DeLamater, Rick. 1986. Pers. knowledge. Phoenix, AZ.
References - 1