Pilosella Cauligera -group
- Family: Daisy Family – Compositae, subfamily Cichorioideae (formerly Chicory Family – Cichoriaceae)
- Growing form: Perennial herb. Often with runners.
- Height: 30–70(–120) cm (12–30(–50) in.). Stem unbranched, hairy, sparsely leaved–leafless, scape-like.
- Flower: Flowers usually 1.5–2 cm (0.6–0.8 in.) wide, single flower-like capitula surrounded by involucral bracts. Capitulum’s ray-florets yellow (outer florets often red-streaked underneath, rarely completely reddish yellow or orange), tongue-like, 5-toothed at tip. Stamens 5. Gynoecium composed of 2 fused carpels. Involucral bracts in many rows, variously glandular, straight and star-shaped hairs. Capitula borne in a corymbose or umbellate cluster terminating leafless scape.
- Leaves: In basal rosette, almost stalkless. Blade linear–narrowly elliptic, with entire margins (sometimes small-toothed), usually densely covered with straight and star-shaped hairs, sometimes also with glandular hairs.
- Fruit: Round, grooved, 1.5–2.5 mm (0.06–0.1 in.) long achene, tipped with off-white–light brown unbranched hairs.
- Habitat: Meadows, shores, ditches, pastures, grazing land, meadows, rocky outcrops, forest margins, lawns, paths, parks, fell tundra.
- Flowering time: June–August(–September).
In the large and diverse group of hawkweeds, genus Pilosella stands out with its basal-rosetted, multi-runnered scape plants. The genus is often further divided in two: the hawkweed group (P. Pilosellina -group) has a single capitulum while species in P. Cauligera -group have many capitula in an umbellate group.
In common with other hawkweed species, Pilosella seeds are formed partly sexually, as in most other plants, and partly without fertilization, apomictically. Apomictic reproduction produces an almost endless amount of microspecies that all differ slightly from one another. The boundaries between species of hawkweed, which partly reproduces sexually, are often vacillating and contractual. They are grouped according to many kinds of criteria and a generally accepted classification has yet to be achieved. Nowadays the genus is separated into major genera, sub-groups within these, and crosses between the species. Defining Cauligera specifically is the kind of exercise that is apt to give professional botanists grey hair, so on these pages it is presented as a single group.
Cauligera -species grow mainly in dry meadows and along banks, and they can also be found among droppings in fields, schist and railway embankments. The majority of microspecies probably travel with people, even though there might also be a handful of native shore bank plants. With its particularly eye-catching orange yellow capitula, orange hawkweed (Pilosella aurantiaca; also known as fox-and-cubs, European hawkweed) departs from the yellows that are typical of Cauligera. Microspecies that are worthy of mention include pale hawkweed ( P. floribunda, also known as yellow devil hawkweed), P. lactuella, tall mouse-ear hawkweed (P. praealta; also known as yellow hawkweed, king-devil), P. cymosa and meadow hawkweed (P. caespitosa).