[Halogeton glomeratus (M. Bieb.) C. Meyer][HALGL][CalEPPC:
Red alert][CDFA list: A] Photographs
Map of Distribution
SYNONYMS: barilla, Anabasis
DESCRIPTION: Erect winter to summer annual with small
fleshy leaves, to 0.5 m tall. Halogeton typically invades
disturbed arid and semi-arid sites with alkaline to saline soils.
Plant tissues accumulate salts from lower soil horizons. The salts
leach from dead plant material, increasing topsoil salinity and
favoring halogeton seed germination and establishment.
Some salt in the foliage consists of soluble oxalates toxic
to livestock, especially sheep. Soluble oxalates cause an acute
reduction in bloodstream calcium (hypocalcemia). Symptoms of poisoning
include staggering and muscular spasms. Toxicity of plant material
depends on environmental conditions, plant maturity, and the condition
of livestock. As little as 12 ounces of foliage can be fatal to
poorly nourished animals. Livestock supplemented with calcium
fortified feeds are less susceptible to the toxic effects. Animals
usually avoid consuming the bitter-tasting foliage if more suitable
forage is available. Introduced from the cold desert regions of
cylindrical, gradually narrowed to the +/- blunt apex, ~ 3-6 mm
long, ~ 1 mm wide, glabrous. First leaves appear opposite, cylindrical,
usually broadest near the tip, with tufts of long white
interwoven hairs in the axils. Tips rounded, with a
short bristle at the apex.
Stems branched, often curved at the base, ascending to erect,
+/- fleshy, usually tinged reddish or purple. Leaves alternate,
sessile, dull green to bluish-green, fleshy, cylindrical, 4-22
mm long, ~1-2 mm wide, broadest at the apex. Apex bluntly rounded,
tipped with a stiff bristle 1-2 mm long. Foliage glabrous,
except for tufts of long white interwoven hairs in the
leaf axils. Leaves deciduous or shriveled in fruit.
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and UNDERGROUND STRUCTURES: Taproots grow slowly and can penetrate soil to
depths of up to 50 cm. Lateral roots may spread up to 46 cm in
Flower clusters numerous and dense in most leaf axils, small,
head-like, with 0-3 bractlets 1.5-2 mm long below each cluster.
Flowers bisexual and female (pistillate). Petals lacking. Sepals
5. Most flowers have petal-like sepals with narrow oblong bases
1-2 mm long and membranous fan-shaped tips 2-3.5 mm long.
Fan-shaped tips greenish-yellow to red-tinged, conspicuously veined.
Some flowers have bract-like sepals 2-3 mm long. Stamens 0 (pistillate
flowers) or 2-5 (bisexual flowers).
and SEEDS: August-October. Utricles (thin-walled one-seeded
fruits) 1-2 mm long, enclosed by sepals. Fruits with
sepals typically hide stems. Utricles loosely enclosed by
fan-shaped sepals contain blackish-brown seeds and are commonly
referred to as black seeds in the literature. Utricles tightly
enclosed by adherent brown bract-like sepals contain brown seeds,
and entire structures are referred to as brown seeds. Seeds +/-
teardrop-shaped, often with 2 points, flattened, ~ 1-2
mm long, with a coiled embryo.
CHARACTERISTICS: Plants turn straw-colored when cool season frosts
begin. Plants with some fruits, particularly those enclosed by
bract-like sepals, may remain intact through winter.
open sites, dry lakebeds, shrublands, roadsides, typically where
native vegetation is sparse. Inhabits arid and semi-arid regions,
especially where winters are cold. Grows on many soil types, but
is adapted to alkaline and saline soils with at least 5800 ppm
of sodium chloride.
depends on yearly rainfall amounts. Great Basin (e Modoc, e Lassen,
Mono, n Inyo cos.), Mojave Desert (s Inyo, e Kern, ne Los Angeles,
w & ne San Bernardino cos.), northern Sierra Nevada (c Placer,
e Nevada cos.); to Idaho, Colorado, Nevada. Previous infestations
now eradicated occurred in the Cascade range (c Siskiyou Co.).
To 1800 m (5900 ft).
by seed. Plants typically produce enormous quantities of seed
(average is ~ 75 seeds per inch of stem). Seeds disperse with
wind, water, human activities, seed-gathering ants, animals, and
when dry plants break off at ground level and tumble with the
wind. Many seeds survive ingestion by animals, including sheep
and rabbits. Plants produce 2 types of seed depending on photoperiod.
Black seeds typically develop after mid-August, lack or have a
short after-ripening period, and remain viable for ~ 1 year. Brown
seeds usually develop before mid-August, are dormant at maturity,
and can survive for ~ 10 years or more under field conditions.
Experimental evidence suggests that the bract-like sepals enforce
dormancy of brown seeds. Cool moist vernalization appears to enhance
germination of brown seeds by decomposing the adherent sepals.
Plants typically produce more black seeds than brown, but the
ratio varies according to environmental conditions. Most black
seeds are shed by early November. Brown seeds may remain on plants
until February. Most seeds germinate late fall to early spring
in cold winter areas, but some germination can occur year round
when conditions become favorable. Black seeds can imbibe water
and germinate in less than 1 hour.
FAVORING/DISCOURAGING SURVIVAL: Halogeton competes poorly with established
perennial vegetation. Overgrazing, human disturbance, and fire
typically reduce desirable vegetation and increase open sites
with bare soil, encouraging invasion and establishment of halogeton.
Fire disturbance often enhances seed germination and favors the
growth of dense stands.
Before flowering halogeton resembles immature Russian thistle
[Salsola tragus L.] or kochia [Kochia scoparia (L.) Schrader].
Unlike halogeton, immature Russian thistle has linear leaves ~
0.5-1 mm wide and lacks hairs in the axils. Kochia has pubescent
leaves that do not have a stiff bristle at the tip. In addition,
Russian thistle seeds are cone-shaped.
Prevention: Halogeton glomeratus is a fleshy annual that
is found on alkaline desert soils in disturbed areas such as roadsides, mining
areas, and heavily overgrazed ranges. It is highly toxic to grazing animals
but has historically been most problematic to sheep in the Great Basin, requiring
as little as 1.5 pounds of green plant forage for death. Prevention on grazing
lands is best accomplished by maintaining good perennial grass and shrub cover
and reducing or eliminating grazing and disturbance during the spring growing
season. Halogeton is well adapted to edaphically severe sites such as mine spoils.
Since many heavily disturbed desert sites are very difficult to revegetate,
prevention around these areas must include early detection and rapid response
to initial halogeton invaders.
Mechanical: Tillage will effectively control halogeton.
However, it is best to avoid increasing disturbance unless successful restoration
of perennials is highly probable.
Biological: There are no currently registered biocontrol
agents available for halogeton. Previously, a stem boring moth (Coleophora porthenica)
was released but never successfully established.
Chemical: 2,4-D was used historically at rates of 2.2 -6.7
kg ae/ha to control halogeton. However, injury to native shrubs and a lack of
desirable forage species adapted to alkali conditions resulted in reduced widespread
2,4-D use. Current recommendations include 2,4-D applied at 1.1-2.2 kg ae/ha
to young plants in the spring prior to the bloom stage in conjunction with revegetation.
Tebuthiuron will provide total vegetative control for up to 3-5 years. Metsulfuron,
which is not currently labeled in California, is also effective at 0.49 oz ai/ha.
Plant Competition: Nonnative forage species including Kochia
prostrata, Agropyron desertorum and A. cristatum have been successfully used
to reseed infested areas. Crested wheatgrass is very competitive and my strongly
suppress or eliminate halogeton. Saline adapted hybrids are most effective due
to the sensitivity of crested wheatgrass to highly saline conditions.
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