Hieracium sect. Hieracium
- Name also: Few-leaved Hawkweeds
- Latin synonym: Hieracium Sylvatica -group, Hieracium Murorum group
- Family: Daisy Family – Compositae, subfamily Cichorioideae (formerly Chicory Family – Cichoriaceae)
- Growing form: Perennial herb. Runnerless.
- Height: 10–60 cm (4–25 in.). Stem leafless or 1–leaved (occasionally 2-leaved), with straight and glandular hairs.
- Flower: Single flower-like capitula 1–2 cm (0.4–0.8 in.) broad, surrounded by involucral bracts. Capitulum flowers yellow, tongue-like, tip 5-toothed. Stamens 5. Gynoecium composed of 2 fused carpels. Involucral bracts in many rows, overlapping, different lengths, narrowly triangular, sharp, varyingly with unbranched, glandular and often stellate hairs, inner bracts with narrowly membranous margins. Capitula 2–20 borne in a lax corymbose cluster.
- Leaves: In basal rosette and sometimes also alternate on stem. Rosette leaves 5–10, quite long-stemmed. Stem leaves 0–1 (occasionally 2), of which largest usually stalked. Blade elliptic–lanceolate–narrowly obovate, glabrous–straight-haired, rosette leaves with notched–round–cordate base, with entire–toothed margin, teeth spreading–arching towards tip, stem leaves narrowly elliptic, with entire–toothed margin.
- Fruit: Uniformly thick–widening towards tip, ca. 10-ridged, finely granular, dark brown, 3–4.5 mm (0.12–0.18 in.) long achene, tip with ring-like border and slightly brownish, unbranched hairs.
- Habitat: Nutritious old forests, broad-leaved forests, forest margins, logging clearings, parks.
- Flowering time: June–August(–September).
Hawkweeds (genus Hieracium) are a very diverse group because their seeds develop without being fertilized, so with the passage of time a large group of independent micro-species are produced. Their diversity is such that it would be a life’s work to disentangle them all. Research into the genus has had a strong foundation in Finland since the 19th century, however, and about 400 micro-species have been described, with about 130 of them in genus Hieracium.
Wall hawkweeds like shady and nutritious forests and their margins, and many have fled human-influenced areas. On the other hand there are hawkweeds that push their way in to man-made environments and which can even be found on park lawns. Wall hawkweeds look like common hawkweeds (H. Vulgata group), although the latter ones are usually not so demanding and grow in places that have been slightly culturally affected. Common hawkweeds are not as leafy as wall hawkweeds, and they usually lose their rosette leaves before flowering time. Common hawkweeds’ leaves are usually clustered around the stem, but wall hawkweeds’ stems are leafless, or have a single leaf at most. Their capitula are very alike but wall hawkweed’s involucres are longer and narrower.
Despite the differences it is not always easy to tell wall hawkweed and common hawkweed apart, and they can both be confused with other yellow-flowered members of the Chicory subfamily. A good identifying mark is the involucral bracts, which overlap in many rows on hawkweeds but are usually in two rows on other members of the Chicory subfamily.