BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Ephedra nevadensis | Nevada Ephedra 



GENERAL BOTANICAL CHARACTERISTICS : 
Nevada ephedra is a coarse, erect, opposite-branched evergreen shrub
which grows from 0.82 to 4.1 feet (0.25-1.25 m) in height [4,5].  Stout,
spreading branches are olive to brownish green and nearly leafless [26].
Young stems are pale green and nearly smooth, whereas old stems, which
may exceed 0.16 inch (4 mm) in thickness, are yellowish to gray with
fissured bark [4].  Roots are typically deep and fibrous [22].
Individual plants are often connected by underground "stolons" which are
produced as branches become covered with wind-blown sand or silt [27].
The leaves of Nevada ephedra have been reduced to small scales, and most
photosynthesis takes place in the stems [24].

Nevada ephedra is primarily dioecious with small greenish-yellow flowers
[5,22].  Ellipsoid staminate cones and single light-brown to
yellowish-green ovulate cones are borne at the nodes of young branches
[4].  Smooth brown seeds or "nutlets" of Nevada ephedra occur singly or
in pairs [4,26].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Seed:  Nevada ephedra produces large quantities of small, smooth brown
seeds at erratic intervals [4,27].  An abundance of seed is produced in
some years but very little in others [18].  Germination occurs over a
wide range of temperatures [31].  In laboratory tests, good germination
was achieved at constant temperatures of 41 to 68 degrees F (5-20
degrees C), and at alternating exposure of 16 hours at 68 degrees F (20
degrees C) followed by 2 hours at 77 degrees F (25 degrees C) [31].
Germination is rapid under favorable conditions and can begin within 2
days.  In laboratory tests, germination was 68 percent completed within
10 days after initial plantings [31].  However, at 41 degrees (5 degrees
C), germination did not begin until the 7th day after planting and was
only 36 percent complete after 14 days [31].  Seed has remained viable
for up to 5 years in storage [4,18].  However, germination may be
significantly reduced in seeds stored for only 1 year [31].  Seeds
commonly germinate from the underground caches of rodents such as ground
squirrels [R. Hunter, pers. comm. 1981].

Vegetative regeneration:  Nevada ephedra sprouts from roots or woody
crowns after fire and other disturbances [30].  New plants commonly
develop from the roots or "stolons" of older clones in the absence of
disturbance [27].

Seedling establishment:  Seedlings are very tolerant of drought and
generally establish well following fall or winter plantings [18,22].



SITE CHARACTERISTICS : 
Nevada ephedra is adapted to range of environmental conditions [3] but
typically grows on arid hills and plains [27].  It occurs on dry, open
slopes, ridges, breaks with southern exposures, canyons, floodplains,
arroyos, and in dry watercourses [5,22].  Nevada ephedra grows well on
gravelly or rocky, often alkaline soils and is tolerant of salt
[5,17,22].  Most sites are well drained or subirrigated [5].

Nevada ephedra typically reaches greatest abundance at the edge of the
salt desert zone [J. A. Young, pers. comm. 1987] but also occurs in
basin big sagebrush, Wyoming sagebrush, gray low sagebrush, and black
sagebrush communities.  It generally grows as scattered plants or in
small clumps but also occurs in isolated, large, pure stands [22].
Plants commonly growing with Nevada ephedra include grama (Bouteloua
spp.), mountain-mahogany (Cercocarpus spp.), saltbush (Atriplex spp.),
juniper (Juniperus spp.), creosotebush (Larrea spp.), and cholla
(Opuntia spp.) [3,22].

Nevada ephedra typically grows below the elevational range of the
closely related green ephedra (Ephedra viridis) [J. A. Young, pers.
comm. 1987].  In Utah, it grows from 4,000 to 6,000 feet (1,220-1,830 m)
[6].


SUCCESSIONAL STATUS : 
NO-ENTRY


SEASONAL DEVELOPMENT : 
Plants generally flower from April to June, and fruit ripens in July
[5,22,25].  However, significant annual variation in phenological
development has been observed [25].  Flowering and fruiting dates were
documented as follows in a 9-year study in southern Nevada [25]:

           year          first flowering    first fruiting

           1968          February 9         April 10
           1969          April 25           May 2
           1970          None               None
           1971          March 21           April 15
           1972          March 18           March 27
           1973          April 18           May 7
           1974          April 25           None
           1975          April 29           May 21
           1976          April 9            None

On harsh sites, plants may exhibit very little vegetative growth, even
during favorable years [27].

Related categories for Species: Ephedra nevadensis | Nevada Ephedra