Hieracium murorum

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 : 376-377

65. H. murorum group. Stems (10-)20-50(-80) cm, with few to numerous stellate and glandular hairs at least in the upper part. Leaves with simple eglandular hairs throughout or glabrous above, and sometimes with stellate hairs beneath; basal very variable, numerous, 20-150 x 15-70 mm, green, elliptical, ovate, lanceolate or oblong, obtuse to acute, entire to deeply laciniatedentate (the teeth often more or less mammiform), attenuate to truncate at base, the outer usually broader, more obtuse and less dentate than the inner; cauline 0-1 (-2), like the basal or bractlike. Capitula (l-)4-15(-numerous), often more or less corymbosely arranged; peduncles often arcuate, with dense stellate and glandular hairs and sometimes an occasional simple eglandular hair. Involucre 7-5-14 x 5-12 mm; bracts obtuse to acute, with numerous glandular hairs, usually few to numerous stellate hairs and sometimes a few eglandular hairs. Stigmas yellow or discoloured. Ligules glabrous or with simple eglandular hairs at apex. 2« = 27, 36. Most of Europe. All except Az BI Cr Fa Sb.

It is difficult to give with confidence the original native distribution. Plants of this group are certainly native in rocky places, grassland and open woodland in much of Europe. In the lowlands they often occur on disturbed ground and other open habitats, which they may have reached relatively recently.

K. H.Zahn in Engler, Pflanzenreich 75-76(IV.28O): 287-342 (1921) describes 345 subspecies and many varieties under H. murorum , and numerous other taxa have been described since. The quick spread of species of this group over large areas of disturbed land may ensure the survival of new variants more readily than in the case of species growing in native habitats where competition may allow only a few achenes to germinate. N. Hylander, Symb. Bot. Upsal. 7(1): 125-274 (1943), has described 143 species, most of them new, belonging to this and the following two aggregate species, which have been introduced into grasslands in Sweden. Many of them are not known elsewhere.

Included species:

H. densiglandulum P. D. Sell & C. West, Bot. Jour. Linn. Soc. 71: 263 (1976) ( H. glandulosissimum (Dahlst.) K. Joh. , non Brenner). • Au Bu Cz Fe Ge He Hu Su.

H. exotericum Jordan ex Boreau, Fl. Centre Fr. ed. 3, 2: 417 (1857). Al Br Co Cz Da Ga Ge He Hs Hu It Ju Rm.

H. gentile Jordan ex Boreau, op. cit. 415 (1857). Al Au Be Bu Co Cz Da Ga Ge Gr He Ho It Ju Po Rs (B, C, K).

H. grandidens Dahlst. , Kungl. Svenska Vet.-Akad. Handl. 25(3): 126 (1893). 2« = 27. Au Br Co Bu Cz Da Fe Ga Ge Gr Hb He It Ju No Po Rm Rs (B, C, W) Su.

H. integratimi (Dahlst. ex Stenström) Dahlst. , op. cit. 112 (1893). • Au Br Cz Da Gr Hu Ju No Su.

H. murorum L. , Sp. PI. 802 (1753). Although this name has always been used for this group of plants in the aggregate sense, it has never been typified and it is uncertain to which of the segregates the name applies.

H. oblongum Jordan, Cat. Jard. Grenoble 1849: 7 (1849). • Al Au Br Cz Ga Ge He Hu It Ju Rm.

H. pellucidum Laest. , Kungl. Svenska Vet.-Akad. Handl. Yľl (1824). • Br Da Fe No Rs (N, B, C) Su.

H. praecurrens Vuk. , Rad Jugosl. Akad. Znan. Umj. 58: 167 (1881). • Al Au Bu Cz Hu Ju Rm Rs (W). (This species shows some characters of H. rotundatum .)

H. semisilvaticum (Zahn) P. D. Sell & C. West, Bot. Jour. Linn. Soc. 71: 266 (1976) ( H. murorum subsp. semisilvaticum Zahn ). • Al Bu Cz Ga Ge Gr He It Ju Rm.

H. subbifidiforme (Zahn) P. D. Sell & C. West, loc. cit. (1976) ( H. murorum subsp. subbifidiforme Zahn ). • Cz Ge Hu Ju PoRm.

H. tenuiflorum Arvet-Touvet ex C. Bicknell , FI. Bordighera 173 (1896). • Co Ga He It.

H. trianguläre A\mą., Stud. Hier. x\\ (1881). • Fennoscandia and Baltic region. Fe No Rs (C) Su.