Polygonaceae - University of Alaska

Rumex krausei Jurtzev & V.V. Petrovsky
Polygonaceae
Synonyms: Rumex graminifolius auct. non Rudolph ex Lamb.
Global Distribution:
Amphi-Beringian.
Alaska Distribution:
Arctic Tundra, Bering Tundra, Intermontane Boreal.
Ecoregions Occupied: Brooks Foothills, Brooks Range, Seward Peninsula,
Bering Sea Islands, Kobuk Ridges and Valleys.
Conservation Status:
S2S3 G2; BLM Sensitive.
Description170
Inner tepals 2.3 to 3 mm long
2 cm
Inflorescences dense,
sparsely branched or
unbranched, compact
or globose when young
Illustration by Dominique Collet
Basal leaves linear or
spatulate-lanceolate, 2.5 to
6 cm long, 1.5 to 5 mm
wide, lacking basal lobes
Stipules brown or red –brown,
membranous
Inflorescences
elongating into
interrupted cluster
with age, occupying
top half of stem
Basal leaves
gradually narrowing
to long petioles
Illustration by Anne-Lillian Schell, courtesy of University of Alaska Museum
275
Rumex krausei
General:
Perennial herb from thick, densely tufted underground
stolons, dioecious; stems erect, solitary or several, 8 to 25 cm
tall; shoots usually densely crowded.
Leaves:
Basal leaves arranged in rosettes, linear or spatulatelanceolate, lacking basal lobes, 2.5 to 6 cm long, 1.5 to 5 mm
wide, bases gradually narrowing to long petioles, entire;
stipules fused to form sheaths, brown or red-brown,
membranous; stem leaves few, reduced.
Flowers:
Inflorescences terminal, occupying the upper half of stems,
compact or globose when young, elongating later into
interrupted clusters, usually unbranched or sparsely branched;
pedicels 1 to 4 mm long; flowers 3 to 7 in whorls, unisexual,
red or red-purple; inner tepals distinctly enlarged, 2.3 to 3 mm
long, 1.8 to 3 mm wide.
Fruits:
Achenes light brown, 1.5 to 2 mm long, 1.2 to 1.9 mm wide.
© Forrest Baldwin 2006
276
Rumex krausei
Ecology
Elevation:
Known from near sea level to 360 m in Alaska.
Landform:
Alpine slopes, frost scars, river terraces.
Soil Type:
Clay, sand, mineral soil, gravel; often associated with
calcareous substrates.
Moisture regime:
Moist to wet.
Slope:
Gentle.
Aspect:
No particular aspect.
Vegetation type:
Sparsely vegetated, Dryas tundra, Dryas-dwarf shrub
tundra, graminoid meadow, forb meadow, sedge-forb
meadow; growing in open microsites.
Associated species:
Eriophorum callitrix, Eriophorum scheuchzeri,
Eriophorum triste, Tephroseris frigida,
Triglochin maritima.
Longevity:
Perennial, likely long-lived as some individuals form
extensive, dense tufts.
Phenology:
Flowering early June through late July.
Population estimate:
There are 11 known occurrences in Alaska; several
populations consist of over 1,000 individuals172 while
other populations consist of 10 to 60 individuals.
Reproductive Biology: Dioecious plants are obligately outcrossing because they
bear flowers of one sex; likely wind-pollinated.
Similar Species42, 169, 170
Material from Alaska corresponding to Rumex aureostigmaticus, Rumex krausei,
and Rumex beringensis has in the past been assigned to Rumex graminifolius,
which is known from northern Fennoscandia to southeastern Yakutia. Rumex
graminifolius is not known from or likely to occur in Alaska. Rumex
aureostigmaticus, Rumex krausei, and Rumex beringensis are similar and likely to
be confused with one another, although they are somewhat separated
geographically. All three species can occur in similar habitats.
277
Rumex krausei
The table below describes the differences in morphology and geographic range
between the three aforementioned Rumex species and the non-native Rumex
acetosella.
Species
Stipules
Rumex krausei
Brown or
red-brown,
membranous
Rumex
beringensis
Brown or
red-brown,
membranous
Rumex
aureostigmaticus
Rumex
acetosella
Whitish,
often
becoming
tattered into
narrow
segments
Brown at
base, silvertinted and
lacerated in
upper half
Inner
Tepals
Range
2.3 to 3
mm long
Northwest
Alaska and St.
Lawrence
Island
1.6 to 2.3
mm long
Southwest
Alaska and
Wrangell
Mountains
Inflorescences
diffuse with
straight, slender
branches
2 to 2.6
mm long
Arctic Alaska
Inflorescences
diffuse and
interrupted
throughout,
branched
1.2 to 1.7
mm long
Anthropogeni
cally disturbed
areas
throughout
Alaska
Inflorescence
Inflorescences
dense, sparsely
branched or
unbranched,
occupying usually
less than top half of
stem, compact or
globose when
young
Inflorescences
interrupted at base,
dense near top,
occupying more
than the top half of
stem, never globose
© Rob Lipkin
278