Myosotis L.

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 : 111-112

29. Myosotis L. 1

Annual or perennial herbs. Flowers in usually paired cymes which are usually ebracteate or sometimes bracteate below. Calyx more or less accrescent in fruit, regularly 5-lobed to halfway to base or more. Corolla rotate; tube usually short; limb regularly 5-lobed, flat or slightly concave, usually blue (sometimes white, yellow or yellow and blue); scales 5, usually included, papillose, white or yellow. Stamens usually included, with a terminal Ungulate appendage; filaments inserted about the middle of the tube. Style included; stigma capitate. Nutlets 4, ovoid, erect, more or less compressed, smooth and shiny, brown to black, often with a distinct rim; area of attachment usually small, sometimes with a spongy or Ungulate appendage.

Literature: J. Grau, Österr. Bot. Zeitschr. I ll: 561-617 (1964); M itt. Bot. Staatssamm. (München) 5: 675-688 (1965); 6: 517-530 (1967); 7: 17-100 (1968). R. Schuster, Feddes Repert. 74: 39-98 (1967). T. Vestergren, Svensk Bot. Tidskr. 24: 449^467 (1930); Ark. Bot. 29 A (8): 1-39 (1938).

1 Calyx with equal and uniform, straight, appressed setae, pointing towards the apex

2 Upper cauline leaves with erecto-patent hairs on upper sur­

face; attachment of the nutlets not spongy; annuals of dry habitats

3 Corolla c. 5 mm in diameter; stem up to the highest leaf with

patent hairs 2. cadmea 3 Corolla not more than 3 mm in diameter; lower part of stem

with patent hairs

4 Pedicels not thickened in fruit, usually patent; stems erect

3. ucrainica 4 Pedicels thickened towards the apex in fruit; stems erect,

ascending or procumbent

5 Inflorescence bracteate 4. pusilla 5 Inflorescence ebracteate, or only the lowermost flowers in

the axils of bracts

6 Calyces up to 3 mm in fruit, crowded and appressed to

the stem 5. litoralis 6 Calyces in fruit rarely appressed, less than 3 mm and

not crowded 1. incrassata 2 Upper cauline leaves with short appressed hairs on upper surface; attachment of the nutlets spongy; annuals or perennials of wet habitats

7 Calyx persistent in fruit, divided at anthesis to less than J

way; teeth broadly triangular

8 Annual or biennial, without stolons; limb of corolla saucer­

shaped; nutlets up to 1 mm, ellipsoid, brown 33. sicula 8 Biennial or perennial, often with subterranean stolons; limb

of corolla flat; nutlets more than 1-5 mm, ovoid, usually

black (36-39). scorpioides group 7 Calyx often caducous at maturity, divided at anthesis to at

least I way; teeth narrowly triangular

9 Stems with patent hairs at least at the base

10 Stolons absent 31. welwitschii 10 Stolons present 30. secunda 9 Stems with appressed hairs or glabrous at the base

11 Stolons present 32. stolonifera 11 Stolons absent

12 Pedicels (except in the single central flower) not longer

than calyx in fruit 33. sicula 12 Pedicels (especially those of the lower flowers) longer

than calyx in fruit

13 Nutlets up to 1-2 mm, brown; main veins of calyx

branched at about the middle of the calyx-tube;

calyx-tube up to 3 mm at maturity 34. debilis 13 Nutlets up to 2 mm, dark brown to black; main veins

of calyx branched at base; calyx-tube up to 6 mm at

maturity 35. laxa

1 Calyx with hooked hairs or with hairs of 2 kinds; some setiform, usually hooked and ±patent; some shorter, slender, straight or curved

14 Perennial or biennial

15 Calyx-teeth lanceolate, obtuse; hairs on calyx straight, those of the teeth pointing forwards, those of the tube backwards

40. azorica 15 Calyx-teeth linear to broadly triangular; hairs on calyx all pointing forwards, or with hooked hairs at the base

16 Nutlets obtuse; attachment-area large, elliptical to orbicular, often slightly but regularly reniform, with lateral folds; calyx narrowed at the base in fruit, never deciduous (21-29). alpestris group 16 Nutlets ±acute; attachment-area small, irregularly reniform, without lateral folds; calyx rounded at the base in fruit, usually deciduous

17 Calyx closed in fruit; limb of corolla saucer-shaped 6. arvensis 17 Calyx open in fruit; limb of corolla flat

18 Nutlets 2-3 mm; calyx shorter than corolla-tube;

hooked hairs of the calyx 0-4 mm, stiff

19 Limb of corolla not more than 4 mm in diameter,

yellowish-white to pale blue 18. soleirolii 19 Limb of corolla up to 8 mm in diameter, usually bright blue

20 Nutlets c. 2 mm; stem not woody at base 19. decumbens 20 Nutlets c. 3 mm; stem woody at base 20. latifolia 18 Nutlets not more than 1-8 mm; calyx equalling or longer than corolla-tube; hooked hairs of the calyx

0-2 mm, soft

21 Pedicels not more than 2-5 mm in fruit; flowers yellowish-white to pale blue 18. soleirolii 21 Pedicels at least 5 mm in fruit; flowers bright to deep blue 17. sylvatica 14 Annual

22 Lower surface of leaves, especially on the veins, and base of stem with hooked hairs; inflorescence-axis with some upwardly projecting or patent hairs

23 Calyx divided to J in fruit, almost all deflexed towards the base of the stem; nutlets narrowly ellipsoid 16. réfracta 23 Calyx divided to j in fruit, all but the oldest patent or pointing towards the apex of the stem; nutlets ovoid

24 Hairs on stem pointing upwards, many appressed; calyx not deciduous in fruit; nutlets without a longitudinal furrow 13. stricta 24 Hairs on stem all patent; calyx deciduous in fruit; nutlets with a ± well-marked longitudinal furrow

25 Leaves broadly ovate, the lower petiolate; calyx with hooked hairs only 15. speluncicola 25 Leaves lanceolate, sessile; calyx with both hooked hairs and soft, straight, deflexed hairs 14. minutiflora 22 Lower surface of leaves and base of stem without hooked hairs; hairs of the inflorescence always appressed

26 Flowers yellow, at least in bud; corolla-tube often lengthening after anthesis; nutlets always with a rim

27 Flowers changing from yellow or cream to blue 9. discolor 27 Flowers remaining yellow

28 Stems rarely more than 10cm; calyx with many stiff hooked hairs; corolla c. 4 mm 12. persoonii 28 Stems up to 20 cm; calyx with few, short hooked hairs;

corolla c. 2 mm 11. balbisiana 26 Flowers blue, rarely white; corolla-tube rarely lengthening after anthesis

29 Pedicels of the lowest flowers much elongated and deflexed in fruit; nutlets with a distinct basal appendage

41. sparsiflora 29 Pedicels rarely more than twice as long as calyx and not deflexed in fruit; nutlets without a distinct appendage

30 Calyx closed in fruit; the lowermost pedicels longer than the calyx, usually directed upwards; nutlets black

6. arvensis 30 Calyx open or half-open in fruit; the lowermost pedicels rarely longer than the calyx, usually patent; nutlets brown

31 Nutlets with a rim; corolla-tube lengthening after anthesis 10. congesta

31 Nutlets without a rim; corolla-tube not lengthening after anthesis

32 Flowers irregularly spaced, often close together but sometimes wide apart; stem often sharply bent several times 8. ruscinonensis

32 Stem straight, with regularly spaced flowers 7. ramosissima