Perennials.  Stolons are not produced.  Rhizomes are short, but dense colonies from rhizomes are seldom produced.  Stems are scapose or may bear 1 or 2 well-defined leaves, and are densely pubescent with long, spreading hairs.  Typical height is from 1 to 2.5 feet.

Inflorescences are open, with a few ascending branches, and a small number of flower heads on evident peduncles.  Branches and peduncles are densely pubescent with minute branched (stellate) hairs and stalked, glandular hairs.

Flower heads are ligulate.  All florets are bisexual and fertile.  Corollas are bright yellow.  Involucres are 8-9 mm high, densely  covered with minute, black, stalked glands and stellate hairs.

Basal leaves (persistent throughout the season) are ovate to broadly oblanceolate, borne on long petioles, and have long-ciliate margins, with coarse teeth and shallow lobes. Stems may bear 1-2 well-developed or small, scale-like leaves that are similar to basal leaves, but smaller.

Plants of woods, open woods, roadsides.  The early flowering period occurs in June, and may be followed during Autumn by a second flowering.  Not native.



Similar species:  In morphology, Hieracium murorum is closest to Pilosella species, but differs in not producing rhizomes.  In addition, unlike Pilosella species, which have untoothed leaves, the leaves of H. murorum are coarsely toothed and borne on petioles.  H. murorum is the Linnaean type for the genus Hieracium.

H. murorum is also similar to H. venosum, which differs in being less pubescent, having somewhat smaller heads, and leaves that are distinctively marked with purple veins.

For additional information on this and other hawkweed species, as well as a list of selected references, see my article, "Understanding Hawkweeds". 






Images and text copyright  and Arieh Tal, 1990 to 2018.  All rights reserved.  ( Terms of use )