Yellow Hawkweed, Meadow Hawkweed, Field Hawkweed, Yellow King-Devil
Hieracium caespitosum Dumort.
Asteraceae (Sunflower Family)
▲ colony of plants in flower
▲ mature flowering plant, showing clustering crowns at base
▲▼ inflorescences
▲▼ inflorescences showing stiff hairs with black bases on flowering stems and on bracts below inflorescence
▲▼ closer view of hairs on flowering stems and leaves
▲▼ closer view of hairs on flowering stems and leaves
▲▼ colonies of crowns and leaves
▲▼ colonies of crowns and leaves
▲ crown base showing short section of rhizome/stolon
Hieracium caespitosum
Dumort., Meadow Hawkweed, Yellow Hawkweed, Field Hawkweed, Yellow King
Devil:
(Bayer
Code:
HIEAU; US Code HIAU)
·
European native, rhizome and stolon-producing, creeping perennial weed that
produces leafless to nearly leafless stems 6-30 inches tall above a rosette
of clustered leaves; stems have many stiff, outspread hairs, many with
darker glands at their base, particularly in upper portion of the stems
·
Basal rosette leaves are medium to light green, alternate, with pointed or
round-pointed tips; leaves usually covered with many long, stiff, white
hairs, but sometimes may be hairless
·
Head inflorescences are 0.5 to 1 inch in diameter, dandelion-like, in
clusters at tips of usually leafless stems; heads have no disk flowers, but
20-50 or more yellow ray flowers; the yellow “petals” have 4 notches in
their flattened tips
·
A single row of bracts below the head form a cylindrical to barrel-shape;
individual bracts are green, linear, with pointed tips; bracts have a center
ridge of black, gland-based hairs; stems just below the heads have the same
black hairs
· Flowering is from mid-spring through mid-summer
·
After flowering the florets from the head become a globe of white hairs from
the pappus (parachute-like hairs) attached to small, brown to black, mature
seed/fruit
·
Prefers low-fertility, acidic, sandy soils; found in lawns, cultivated
fields, pastures, non-crop areas, right-of-ways
·
More common in northern Midwest, and is a problem due to the monocultures it
develops as it spreads laterally by stolons and rhizomes
·
Similar species:
o
Orange Hawkweed
(Hieracium aurantiacum) looks
very similar to yellow hawkweed in leaf shape, growth form and height,
except it has orange to red-orange florets in its flower heads
o
Tall Hawkweed
(Hieracium piloselloides) looks
very similar, but has leaves that are hairless except for long white hairs
along the leaf edges, and along the midvein on the leaf undersides
o
Common Catsear
(Hypochaeris radicata) has
similar yellow flowers, but has a more branched, open clustering of flower
heads, and individual heads have long supporting stalks; also the basal
rosette leaf margins of common catsear are widely lobed, not smooth or
toothed, as with yellow hawkweed
o
Smooth Hawksbeard
(Crepis capillaris) has similar,
but smaller, yellow flowers, but they are in larger, more open clusters;
plus stems and basal leaves are hairless, and basal leaves have deep,
pointed lobes, and there are smaller leaves along the flowering stems
o
Dandelion (Taraxacum
officinale) has similar flowers, but has nearly hairless, deeply toothed
rosette leaves, and flowering stems are single, pale green to pinkish,
hollow and leafless