BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Oxytropis sericea | Whitepoint Locoweed 



GENERAL BOTANICAL CHARACTERISTICS : 
Whitepoint locoweed is a native, perennial, leguminous forb that grows
from 6 to 12 inches (15.2-30.4 cm) tall [12,43].  Leaves are 1.6 to 8
inches (4-20 cm) long [35].  Legumes are erect, oblong, or ovoid-oblong
and are 0.4 to 1.0 inch (1-2.5 cm) long [35].  One plant may have many
flowering stalks, each with 6 to 27 flowers [12].  Each flower produces
many seeds.  Whitepoint locoweed has a long taproot [30].




RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Whitepoint locoweed reproduces sexually from kidney-shaped seed.  Seed
pods are hairy and leatherlike [38].  Seeds have hard, impermeable seed
coats and remain viable in the soil for many years.  A large, dormant
seed reserve is retained in the soil to permit exploitation of favorable
environmental conditions [30].


SITE CHARACTERISTICS : 
Whitepoint locoweed occurs on open, well-drained slopes of the western
plains, the foothills of the Rocky Mountains, and grassy subalpine
openings bordered by open wooded hillsides or coniferous forests
[410,26].  It is infrequent to common on prairie uplands, streambanks,
valleys, and alpine sites [35].

Whitepoint locoweed occurs on sandy, gravelly, or rocky soils but grows
best on sandy loams.  It is tolerant of moderately saline soils and low
nutrient conditions but does not tolerate water-saturated soils such as
heavy clay [38].  Whitepoint locoweed is drought tolerant but is not
tolerant of excessive shade.  It is tolerant to freezing temperatures
during the growing season and competes well on nutrient-rich, deep loam
on subalpine sites [30].

Whitepoint locoweed has adapted a stress-tolerant survival strategy
characteristic of plants in arctic and alpine habitats.  It has a large
seedbank that remains viable for many years.  Its principal stresses are
low temperatures, desiccating effects of strong winds on rocky slopes,
intense solar radiation, and mineral nutrient deficiencies [30].

Whitepoint locoweed thrives at medium elevations but grows at elevations
up to 11,000 feet (3,708 m) in Colorado [3].  Regional elevation
distributions are as follows [3,4,25]:

                                 feet                meters

     Utah                     5,800- 9,800         1,768-2,987
     Colorado                 3,500-11,000         1,067-3,353
     Wyoming                  4,000-10,500         1,219-3,201
     Montana                  3,000-10,000           914-3,048
     Arizona                  7,000- 8,000         2,134-2,439
     New Mexico               7,000- 8,000         2,134-2,439
     Alberta                  4,500- 7,000         1,370-2,134

Common associated species not listed in Distribution and Occurrence are
as follows:  junegrass (Koeleria cristata), needleandthread (Stipa
comata), buffalograss (Buchloe dactyloides), western wheatgrass
(Pascopyrum smithii), squirreltail (Elymus elymoides), green needlegrass
(S. viridula), Idaho fescue (Festuca idahoensis), Arizona fescue (F.
arizonica), bluebunch wheatgrass (Pseudoroegneria spicata), muttongrass
(Poa fendleriana), Kentucky bluegrass (P. pratensis), Arizona fescue (F.
arizonica), Indian ricegrass (Oryzopsis hymenoides), sand dropseed
(Sporobolus cryptandrus), red threeawn (Aristida longiseta), Wyoming big
sagebrush (Artemesia tridentata ssp. wyomingensis), alpine sagebrush (A.
scopulorum), plains prickly pear (Opuntia polyacantha), Hood's phlox
(Phlox hoodii), low rabbitbrush (Chrysothamnus viscidiflorus), sedges
(Carex spp.), aster (Aster spp.), daisy (Erigeron spp.), yarrow
(Achillea spp.), quininebush (Garrya flavescens pallida), scarlet
globemallow (Sphaeralcea coccinea), slimflower scurfpea (Psoralea
tenuiflora), locoweed (Astragalus spp.), purple prairie-clover (Dalea
purpurea), broom snakeweed (Gutierrezia sarothrae), dotted gayfeather
(Liatrus punctata), arrowleaf balsamroot (Balsamorhiza sagittata), and
grassland Indian paintbrush (Castellaja lutescens) [2,7,9,19,25,26].
   


SUCCESSIONAL STATUS : 
Facultative Seral Species

Whitepoint locoweed is an important colonizer following disturbance on
western rangelands [26].  It also occurs in climax meadow and sagebrush
steppe communities.
  


SEASONAL DEVELOPMENT : 
Whitepoint locoweed is one of the first species to commence growth in
early spring on many western rangelands.  Growth begins in early April
and plants remain green and succulent throughout the summer [2,28].
First bloom for whitepoint locoweed occurs in mid-June to early July.
Seed dissemination begins in mid-July and lasts until mid-August [22].
The plant begins to dry in late September.  

Some reported dates for anthesis in some western states are as follows
[3]:

          Utah                    May-July
          Colorado                May-August
          Wyoming                 March-August
          Montana                 May-August

Related categories for Species: Oxytropis sericea | Whitepoint Locoweed