Thymus L., 1916

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 172-174

33. Thymus L. 1

Small shrubs or perennial herbs, woody at least at base. Verticillasters 1- to many-flowered, often crowded into a terminal, capitate inflorescence. Calyx cylindrical to campanulate, usually 2-lipped with the 3 upper teeth different from the lower; tube straight, not gibbous, hairy in the throat. Corolla 2-lipped, with straight tube. Stamens usually exserted, straight, divergent.

Literature: V. Borbas, Math. Term. Közl. 24: 37-116 (1890). E. Huguet del Villar, Cavanillesia 6: 104-125 (1934). J. Jalas, Veröff. Geobot. Inst. Riibel (Zürich) 43: 186-203 (1970). M.

Klokov, Not. Syst. (Leningrad) 16: 293-318 (1954). M. Klokov & N. Schostenko, Trav. Inst. Bot. (Charkov) 14(3) ( 107-157 (1939). C. C. Lacaita, Cavanillesia 3: 20 -47 (1930). B. Pawlowski Fragm. FI. Geobot. 12: 387-412 (1966). C. D. Pigott, New Phytol. 53: 470-495

(1954). K. Ronniger, Feddes Repert. 31: 129-157 (1932); Deutsche Heilpfl. 10(5) 5) -24 (1944). P. Schmidt, Hercynia 5: 385-419 (1969). J. Velenovskÿ, Beih. Bot. Centr. 19(2): 271 -287 (1906). The flowering stems may be hairy on all sides, on two sides, or on the angles only. Leaf-measurements refer, unless otherwise stated, to leaves from the middle part of flowering stems; they include the petiole. At least the distal pairs of lateral veins of the leaves, when visible, may anastomose to form a marginal vein either at the apex of the leaf or along the whole length of the leaf. Leaf-venation is best seen in drieds pecimens. Gynodioecism is usual in the genus, pistillate flowers often having smaller calyx and corolla; measurements of calyx and corolla refer to herma­ phrodite flowers.

Hybrids are frequently formed, even between members of different sections as well as between species at different levels of polyploidy.

1 Calyx-tube dorsally flattened,with20-22veins;leavessub-

triquetrous 1. capitatus 1 Calyx-tube dorsally convex,with 10- 13veins;leavesnot

subtriquetrous 2 Upper calyx-teethlikelower(Iberianpeninsula) 3 Bractssimilarto the leaves; upper calyx-teeth 2-3 mm

2. mastichina 3 Bracts not similartotheleaves;uppercalyx-teeth1-1-5 mm

3. tomentosus 2 Upper calyx-teethconspicuouslydifferentfromlower 4 Lower calyx-teethalmostleaf-like,triangular 4.caespititius 4 Lower calyx-teethlanceolate-subulate 5 Leaf-marginsrevolute 6 Bracts notsimilarto leaves, atleast twice aswide asleaves

7 Leaves lineartonarrowly lanceolate

8 Creepingshootsabsent

9 Corolla 6- 10 mm;bractsoftensparselydentate to

shallowlylobed 8. villosus

9 Corollac. 15 mm;bractsentire

10 Bracts membranous,whitish; corolla whitish

10.membranaceus

10 Bractscoriaceous,purplish; corollapurple

11 Inflorescenceupto 4 cm,oblong-conical;leaves

tomentoseandwith afewlongerhairs,ciliate at

base 7.cephalotos

11 Inflorescencenot morethan 2 -5 cm,subglobose;

leavestomentosebutwithoutlongerhairs,not

orsparselyciliate atbase 9.longiflorus

8 Creepingshootspresent

12 Leaves glabroustosubglabrous;bractspurplish

12. mastigophorus

12 Leaves ±velutinous;bractsgreenish

13 Leavesshortlypetiolate 13. dolopicus

13 Leavessessile 15. parnassicus

7 Leaves ovate-lanceolate

14 Leaves glabrousonupper surface 18.caraosus

14 Leavestomentoseonuppersurface

15 Inflorescence6- 8 mm indiameter;calyx 3-4 mm, the

upperteethrarelyciliate 16. capitellatus

15 Inflorescence 10-18 mm indiameter;calyx4-6 mm,

the upperteethusuallyciliate 17. camphoratus 5 Bracts ±similartoleaves

16 Leaves morethan 3 mmwide, ovate torhombic; corolla-

tube ±infundibuliform (Balkanpeninsula) 6.teucrioides

16 Leaves upto2- 5 mmwide,linear toelliptical;corolla-

tube cylindrical

17 Leaves notciliate 19. vulgaris

17 Leaves ±ciliate,at least atbase

18 Long,arcuate,procumbentor creepingshoots absent 19 Calyx 5-7 mm, the tube cylindrical; verticillasters 2-flowered 11. antoninae 19 Calyx 3-4 mm, the tube campanulate; verticillasters 6- or more-flowered, or inflorescence capituliform 20 Calyx shortly tomentose, the upper teeth not ciliate; inflorescence elongate, interrupted 21. zygis 20 Calyx pubescent, the upper teeth ciliate; inflorescence usually capituliform 21 Leaves 3-5 mm, petiolate; corolla pinkish-purple 20. hyemalis 21 Leaves (4-)5-8(-10) mm, sessile; corolla creamy white 22. baeticus 18 Long, arcuate, procumbent orcreeping shoots present 22 Calyx c. 3 mm 23. hirtus 22 Calyx 3 - 5-5-5 mm 23 Upper calyx-teeth 0-5-0-7 mm 25. serpylloides 23 Upper calyx-teeth 1-2 mm 24 Leaves subglabrous, sparsely ciliate at the base (Spain) 24. loscosii 24 Leaves puberulent to velutinous orglabrous,ciliate to above the middle (S. E. Europe) 25 Leaves 1 -1- 5 mm wide, shortly petiolate 13. dolopicus 25 Leaves 0-3-1mm wide,sessile 14. cherlerioides 5 Leaf-margins not or only slightly revolute 26 Stems with hairs on the angles only 27 Leaves with marginalvein 60. bihoriensis 27 Leaves without marginal vein 28 Leaves truncate to subcordate at base; upper calyx- teeth -lo-i as long as calyx 63. oehmianus 28 Leaves cuneate to subtruncate at base; upper calyx- teeth at least | as long as calyx 29 Creeping, non-flowering, terminal shoots present 62. alpestris 29 Creeping,non-flowering, terminal shootsabsent 61. pulegioides 26 Stems hairy all round or on 2 opposite sides 30 Leaves not ciliate 31 Branches erect 5. piperella 31 Branches procumbent, ascending 32 Leavesoblong-elliptical 47. nitens 32 Leavesovateto ovate-elliptical 33 Leaves 5-7 x 2-3 mm; flowers not in a distinct inflorescence 48. willkommii 33 Leaves 7-12 x 3-6 mm; flowers in capitate in­ florescences 49. richardii 30 Leaves ciliate at leastatbase 34 Bracts ovate, not similar to the leaves 35 Uppercalyx-teethnotmore than0-7 mm 36 Leaves acute, often denticulate, velutinous 26. holosericeus 36 Leaves obtuse, entire, glabrous 37 Leaves c. 1 mm wide, fleshy; veins indistinct 39. zygioides 37 Leaves 1-7-2 mm wide, not fleshy; veins distinct 37. aznavourii 35 Upper calyx-teeth 0-8 mm or more 38 Leaves puberulent to velutinous 39 Calyx 6-8 mm; leaves velutinous 27. laconicus 39 Calyx 3 - 5-5 mm; leaves puberulent 30. aranjuezii 38 Leaves glabrous, sometimes ciliate 40 Largest bracts at least 5 mm wide 41 Leaves 7-10 mm, coriaceous; corolla 8-12 mm 29. granatensis 41 Leaves 10-17 mm, herbaceous; corolla 6-8 mm 28. bracteosus 40 Largest bracts not more than 4 mm wide 42 Leaves 1- 5—2 mm wide, herbaceous; calyx-tube distinctly shorter than lips 31. bracteatus 42 Leaves not more than 1- 2 mm wide, coriaceousor ± fleshy; calyx-tube about as long as lips 43 Leaves 5-9 mm, narrowly spathulate, ±fleshy;

veins indistinct, diverging 30. aranjuezii 43 Leaves 8-20 mm, linear, ±coriaceous; veins distinct, parallel

44 Calyx 5-7 mm; bracts straw-coloured 33. atticus 44 Calyx 3-5 mm

45 Corolla pink, becoming yellow; bracts strawcoloured 34. plasonii 45 Corolla whitish, pink or purple; bracts usually purplish 35. striatus 34 At least the lowermost bracts ± similar to the leaves (although sometimes wider and sometimes coloured)

46 Marginal vein present along the whole length of the leaf (Carpathians)

47Creeping, non-flowering branches present

58. pulcherrimus 47 Creeping, non-flowering branches absent

59. comosus 46 Marginal vein absent or present in upper part of leaf only

48 Flowering stems usually more than 10cm; nonflowering branches usually absent

49 Stems with hairs on two sides 64. alternans 49 Stems usually with hairs all round

50 Upper calyx-teeth ciliate

51 Leaves elliptic-spathulate, petiolate, with two pairs of distinct lateral veins forming a marginal vein at the apex 51. binervulatus 51 Leaves linear to lanceolate-elliptical, with lateral veins indistinct or disappearing towards the margin

52 Calyx 3-5-5 mm; upper teeth up to 1-5 mm

53 Bracts with distinct veins; inflorescence interrupted 40. comptas 53 Bracts with indistinct veins; inflorescence capitate 36. spinulosus 52 Calyx 2-5-3-5(-4) mm; upper teeth c. 1 mm

54 Inflorescence often branched; leaves coriaceous, with distinct venation 41. sibthorpii 54 Inflorescence seldom branched; leaves herbaceous, with weak venation 42. pannonicus 50 Upper calyx-teeth not ciliate

55 Leaves linear to lanceolate, sessile

56 Inflorescence interrupted; upper calyx-teeth up to 1-5 mm 40. comptas 56 Inflorescence capitate; upper calyx-teeth c.

1 mm 45. pallasianus 55 Leaves elliptical to rhombic-ovate, petiolate

57 Leaves acute, with indistinct veins

46. herba-barona 57 Leaves subobtuse, with distinct veins

50. guberlinensis 48 Flowering stems seldom more than 10cm; long, creeping non-flowering branches present

58 Upper calyx-teeth O-3-O-7 mm, not ciliate

59 Leaves ±sessile ; calyx 4-4-5 mm; both sparsely glandular-punctate 37. aznavourii 59 Leaves shortly petiolate; calyx 3-4 mm; both densely glandular-punctate 38. kirgisorum 58 Upper calyx-teeth usually more than 0-7 mm, usually ciliate

60 Leaves with indistinct lateral veins

61 Leaves ± spathulate

62 Upper calyx-teeth 1-1-5 mm, not ciliate

32. leptophyllus 62 Upper calyx-teeth O-3-O-7 mm, ciliate

39. cygioides 61 Leaves linear to elliptical, rarely obovate

63 Leaves less than 1 mm wide, ciliate at least in the basal half 14. cherlerioides 63 Leaves at least 1 mm wide, ciliate only at base

64 Flowering stems with a basal cluster of small leaves; calyx 2-5-4(-5) mm 65 Calyx-tube about as long as upper lip

54. stojanovii

65 Calyx-tube shorter than upper lip

55. longicaulis

64 Flowering stems without a basal leaf-cluster;

calyx 4-5 mm

66 Creeping shoots usually with a terminal inflorescence 43. glabrescens

66 Creeping shoots without a terminal inflorescence 24. loscosii

60 Leaves with distinct lateral veins

67 Leaves with lateral veins curved along the margin and anastomosing at apex 56. praecox

67 Leaves with lateral veins disappearing towards the margin

68 Calyx-tube clearly shorter than upper lip

69 Flowering stems without a basal cluster of small leaves; calyx 5-6 mm 44. longedentatas

69 Flowering stems with a basal cluster of small leaves

70 Calyx 4-6 mm, purplish 53. thracicus

70 Calyx 2-5-4 mm, greenish or purple

71 Leaves coriaceous 52. ocheus

71 Leaves herbaceous 55. longicaulis

68 Calyx-tube about as long as upper lip

72 Leaves up to 1-5 mm wide; flowering stems hairy on 2 opposite sides only 57. nervosus

72 Leaves mostly more than 1-5 mm wide;

flowering stems usually hairy all round

73 Leaves sessile or nearly so

74 Upper calyx-teeth about as long as wide

65. serpyllum

74 Upper calyx-teeth distinctly longer than wide

75 Leaves coriaceous; creeping shoots without a terminal inflorescence 35. striatus

75 Leaves herbaceous; creeping shoots ending in an inflorescence 43. glabrescens

73 Leaves distinctly petiolate

76 Petiole often up to j of the total leaf-length

66. talijevii

76 Petiole not more than | of the total leaflength 65. serpyllum