BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Sambucus cerulea | Blue Elderberry 



GENERAL BOTANICAL CHARACTERISTICS : 
Blue elderberry is a short lived, shade intolerant (or slightly tolerant
[58]) shrub or small tree [50,61], usually between 6.5 to 13 feet (2 to
4 m) tall, but sometimes reaching 20 feet (6 m) [6,27].  Young twigs are
soft and pithy but the wood is quite hard [49] with grayish bark [76] or
thin, dark brown irregularly furrowed and ridged bark [56].  There may
be a thick taproot with fibrous, spreading, lateral roots [20,69].  The
leaves are opposite and odd-pinnate with five to nine serrate leaflets
[56].  The flowers are perfect, white or cream colored, and borne in a
cyme.  The entire inflorescence is about 1.6 to 5.9 (7.9) inches (4 to
15 [20] cm) across and nearly flat topped. The fruit is globose, edible,
and blue-black with a glaucous bloom that makes it appear to be powder
blue [6,27,56].




RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Reproduction of blue elderberry is sexual through small nutlets, three
to five of which are contained in each edible, berrylike fruit [27,76].
There are good seed crops almost every year, and the seeds are dispersed
by birds and other animals that eat the fruit [20,86].  Seeds retain
their viability for up to 16 years in storage [20].  Blue elderberry
seeds have a hard seed coat and dormant embryos that delay germination
[58].  Heat treatment or sulfuric acid scarification and stratification
hasten germination.  Detailed descriptions of seed gathering and
germination are in Schopmeyer [68], Heit [26], Landis and Simonich [38],
Shaw [69], and Stanton [75].  Without treatment, germination of
seedlings may be delayed from 2 to 5 years after planting.

Seedlings of blue elderberry develop extensively branched shoot systems
with numerous large leaves [69].  They also grow expansive root systems
that make it difficult to cultivate blue elderberry seedlings in seed
beds [38,69].  Seedlings may bloom and bear fruit by their 2nd or 3rd
year [16].  Plants can reach full size in 3 to 4 years in the
Intermountain region [58].

Vegetative reproduction is limited to vigorous coppicing if the stems
are killed or injured [61,90].


SITE CHARACTERISTICS : 
Blue elderberry prefers moist, well-drained sunny sites [9,76,75,90].
Thus it is found as a seral species on forested sites where it may
persist in openings, in ravines, and alongside roads in drier habitat
types, and as a riparian species in California's Central Valley and in
Arizona [2,4,16,25].  In the Northwest it grows in valley bottoms and on
open slopes with sufficient moisture [6,27].  It is the most common
elderberry in eastern Oregon and Washington and is generally found along
fence rows or in stream valleys [24].  In Utah it is found in the
riparian, sagebrush (Artemisia spp.), mountain brush, pinyon-juniper
(Pinus edulis-Juniperus utahensis), ponderosa pine (Pinus ponderosa),
aspen (Populus tremuloides), and spruce-fir (Picea engelmannii-Abies
lasiocarpa) communities [58,93].  Near the limits of its range it is
more restricted.  In southeastern British Columbia and Vancouver Island
it is found only in the valley bottoms where the growing seasons are
longer [20].  In western Colorado it grows along creeks, in valleys, and
at the base of cliffs [23].  In Arizona it is found locally in boreal,
riparian shrublands and becomes more important below 8,500 feet (2,591
m) [4].  In general, blue elderberry is more common on warmer sites than
the closely related red elderberry (Sambucus racemosa), although their
preferred sites overlap [34].

Soils:  Blue elderberry grows on a variety of soils from gravelly or
stony [28] to heavy clay loam [11].  However, growth is good on loam,
and sandy loam soils; fair to good on sand; fair to poor on clay or
gravel and poor on dense clay.  There is no consensus about elderberry's
growth on organic and acidic soils; however, there is agreement that it
grows poorly on saline, sodic, and saline-sodic soils, and optimum soil
depth is given as 20+ inches (51 cm) [10].  Mueggler [50] found that
elderberries were associated with soils that contained 5.6 to 8.0+
percent organic matter.

Elevation:  Blue elderberry is most common from sea level to moderate
elevations in the mountains [9,27].  However, it grows to 10,000 feet in
California (3,048 m) [54] and 9,514 feet (2,900 m) in the Pacific
Northwest [6].  In western Colorado it is reported at 5,500 to 8,000
feet (1,692 to 2,438 m) [23].


SUCCESSIONAL STATUS : 
Blue elderberry is a short lived seral species that is shade intolerant
[50,61] or slightly shade tolerant [58].  It is a component of the seral
shrub field complex that can inhibit tree regeneration following fire in
moist Northwest forests but it is seldom a primary competitor
[7,20,50].  In an Idaho study elderberries were absent from stands
where over 40 years had passed since fire [50].  In open forests,
woodlands, chaparral or riparian zones, blue elderberry can remain in
the community, usually as scattered individuals rather than assuming
dominance [2,4,16,25,51,52].


SEASONAL DEVELOPMENT : 
The average dates of phenological events in Montana and Idaho are presented
below [67].

                        Average Date              Average Date
                         West of the               East of the
                      Continental Divide        Continental Divide

Leaf Buds Burst             4/30                      6/1
Leaves Full Grown           6/4                       6/28
Flowers Start               6/2                       6/27
Flowers End                 6/28                      7/16
Fruits Ripe                 8/21                      8/22
Seed Fall Starts            9/18
Leaves Start to
  Color and Wither          8/31
Leaves Begin to Fall        9/19
Leaves Fallen              10/12                      9/20

In Idaho May to July is the flowering time [56].  In California bloom is
from June to September with fruiting in September [54].  In Utah bloom
occurs in July and August with fruiting from August to October [86].

Related categories for Species: Sambucus cerulea | Blue Elderberry