Galium pyrenaicum, Gouan

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1976, Flora Europaea. Volume 4. Plantaginaceae to Compositae (and Rubiaceae), Cambridge University Press : 29

85. G. pyrenaicum Gouan , Obs. Bot. 5 (1773).

Forming a cushion up to 20 cm in diameter. Stems 3-7 cm, erect to ascending, 4-angled, glabrous. Leaves 4-5-6 x 0-5-0-7 mm, in whorls of 6, imbricate, linear, acicular, distinctly awned, often blackish when dry; midrib not distinct beneath. Inflorescence elongate, few-flowered, leafy; pedicels 0-5-5 mm. Corolla 1-9-2-2 mm, cup-shaped; tube О-4-О-5 mm; lobes 1-5-1-7 mm, slightly longer than wide. Filaments О-6-О-8 mm; anthers 0-3-0-5 mm. Fruit c. 1-5 mm, glabrous, finely granulate. 2л = 22, 44. Rocks and open alpine grassland. • Pyrenees, and high mountains of N., S.E. & S. Spain. Ga Hs.

The diploids and tetraploids cannot yet be distinguished morphologically. This species hybridizes rather extensively with 126. Sect. LEPTOGALiUM Lange. Perennial herbs, laxly or sometimes densely caespitose, with slender stock and rhizome, and usually with long, filiform stolons. Stems slender, often less than 30 cm, 4-angled, hairy, glabrous or sometimes retrorsely aculeolate. Leaves usually in whorls of 6-10, 1-veined, with a short cartilaginous to long hyaline apex. Inflorescence rather lax, ovoid, pyramidal or corymbose, with corymbiform partial inflorescences and usually ebracteate ultimate branches, or reduced, fewflowered and more or less leafy. Corolla rotate, purple, pink, greenish, yellowish or white; lobes acute to apiculate. Fruit dry, acutely papillose or smooth, very rarely hairy, never glochidiate.

Apart from the G. baldense group (119-123), the species pair 124-125, and the more isolated taxa 118 and 126, the Section comprises the closely interrelated complex of species 86-88 around G. rubrum and 91-117 around G. pusillum , as well as the hybrids 89-90 linking them. Both the complex 86-88 and especially the complex 91-117 are extremely polymorphic and are highly intricate polyploid complexes. Because of the many intermediate allopolyploid forms, taxonomic treatment, construction of keys and determinations are difficult. It is helpful to recognize, within the complex 91-117, several even more closely related (but again overlapping) clusters of species: 94-97, 98-100, 102-104, 104-110 and 111-114.