- Name also: Wood Cudweed, Woodland Arctic Cudweed (USA)
- Latin synonym: Omalotheca sylvatica
- Family: Daisy Family – Compositae, subfamily Asteroideae
(formerly Aster Family – Asteraceae)
- Growing form: Perennial herb.
- Height: 15–50 cm (6–20 in.). Stem branchless, densely gray-haired, base with usually flowerless rosettes.
- Flower: Single flower-like 5–7 mm (0.2–0.28 in.) capitula surrounded by involucral bracts. Capitula’s ray-florets lacking; disc florets light brown, tubular, small. Stamens 5. Pistil of 2 fused carpels. Involucral bracts overlapping, shiny, membranous, tip light brown–straw-coloured, occasionally dark brown, inner bracts around same length as ray-florets. Capitula borne in a quite lax spike, usually over 1/3 length of stem.
- Leaves: Alternate, ascending oblique, becoming progressively smaller towards top, short-stalked–stalkless. Basal leaf blades narrowly lanceolate, stem leaf blades linear, tapered, with entire margins, usually 1-veined, top sparsely haired, dull green, underside densely white-haired.
- Fruit: Elliptic, yellowish brown achene, tip with slightly brownish–reddish unbranched hairs.
- Habitat: Meadows, sand pits, wasteland, forest margins, logging sites, sides of forest roads.
- Flowering time: July–August.
Heath cudweed thrives best in dryish forest, from where it has spread to meadows and pastures and even become a weed among crops. It is quite visible all year round: its greyish appearance means that it doesn’t merge into other vegetation but rather stands out, even in sparse stands. Its erect stems stick up through the snow in the winter, making it very easy for its achenes to spread with their flying hairs. The species is widespread, fairly large and quite common, but it has not been researched much – perhaps because it is too common.
Heath cudweed is quite rare north of the Arctic Circle, where it is replaced by its relative highland cudweed (G. norvegicum). Heath cudweed grows here and there, however, and has been identified in Muonio, Kittilä, Sodankylä and Savukoski. In Lapland the species grows mainly close to inhabited areas or places that people have changed. Both cudweeds can be found growing together in such places, although highland cudweed usually prefers damper ground than its relative. Heath and highland cudweed comprise the largest pair of cudweed species in Finland, and the best way to tell them apart is by the form and vein-pattern of their leaves: heath cudweed’s leaf blade is narrowly lanceolate, often grooved and recurved at the tip, its upper surface is 1-veined and quite glabrous, and for that reason it is quite green.