Pilosella caespitosa


Pilosella caespitosa
is like several other Pilosella species and has a similar appearance to many of the hawkweeds.

Description

Pilosella caespitosa is a creeping perennial,
with shallow, fibrous roots
and long rhizomes.
The leaves, hairy on both sides, are up to 6 inches long, spathulate, and almost exclusively :wiktionary:Basal#Adjective|basal with the exception of 1 or 2 very small :wiktionary:cauline|cauline leaves. The leaves lie flat to the ground, overlap, and will smother non-vigorous :wiktionary:turf#Noun|turf.
The stems are bristly and usually leafless, although occasionally a small leaf appears near the midpoint.
Stems, leaves, and bracts have dense, blackish hairs
and exude milky juice when broken.
The 1/2 inch flower heads appear in tight :wiktionary:cluster#Noun|clusters at the top
of the 1 to 3 foot stems with 5 to 40 flowers per cluster.
:wiktionary:corolla#Noun|Corollas are all :wiktionary:ligule|ligulate and bright yellow.
Each single flower head is an inflorescence and each petal forms its own seed, making them each a separate flower or
:wiktionary:floret|floret.
The seeds are shiny, black, and plumed.
After maturing they are dispersed by wind, clothing, hair, feathers, and some vehicles that disturb fields or soils. P. caespitosa persists and regrows each year from rhizomes and often spreads by stolons,
which can be extensive, creating a dense mat of hawkweed plants that practically eliminates other vegetation.
P. caespitosa prefers silt loam, well-drained soil: coarse textures, moderately low in organic matter, and moist. Its presence can be an indicator of low soil fertility or slightly acidic soils.
P. caespitosa has, in the past, been used for healing eyesight. Pliny the Elder had recorded information regarding how other species, specifically hawks, utilized P. caespitosa, specifically believing that they would eat it in an effort to improve eyesight.

Habitat and distribution

Tolerant of drought and :wiktionary:trample|trampling, this species finds its habitat where the soil has been neglected. Places like :wiktionary:roadsides|roadsides, neglected residential and commercial landscapes, minimally maintained public parks and open spaces, vacant lots, :wiktionary:rubble|rubble dump sites, and abandoned grasslands.
P. caespitosa is an introduced species in North America and can be found in Canada
and the United States. It is considered a noxious weed in Idaho, Montana, Oregon and Washington.
P. caespitosa's native range includes a large portion of Europe, including Austria, Belarus, Bulgaria, Czechoslovakia, Estonia, France, Finland, Germany, Greece, Hungary, Latvia, Lithuania, Norway, Poland, Romania, Sweden, Switzerland, Ukraine, and Former Yugoslavia.