Rhinanthus 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 : 276-277

35. Rhinanthus L. 1

( Alectorolophus Zinn )

Annual, hemiparasitic herbs. Leaves opposite, sessile, entire to dentate. Flowers in terminal, bracteate, spike-like racemes. Calyx laterally compressed, ovate to suborbicular, shortly 4-toothed, accrescent. Corolla mainly yellow, with a long tube and 2-lipped limb; upper lip galeate, laterally compressed, with 2 teeth slightly below the apex; lower lip slightly shorter than upper, 3-lobed. Stamens 4, didynamous, included under upper lip of corolla; anther-lobes hairy, not mucronate. Capsule loculicidal; seeds few, more or less discoid, usually with a marginal wing.

In this and related genera the leaves on the main stem which lie between the uppermost branches and the lowest flowers of the terminal spike are known as intercalary leaves.

‘Glabrous’, when used of the calyx in this genus, refers to the main surfaces; the margin may be scabrid or slightly puberulent. The species of Rhinanthus show a recurrent pattern of variation similar to the ‘pseudoseasonal polymorphism’ described for Melampyrum (p. 253). Since, however, the principal habitat of most species of Rhinanthus is meadows cut for hay the seasonal aspect is less marked, and for this and other reasons the ecotypic variants are less easily distinguished than in Melampyrum . Nevertheless, the general pattern of this variation is so conspicuous and so constant in its general outline that it has been thought best to list, as for Melampyrum , the recurrent ‘ecotypic variants’ for those species in which they have been recognized, each being listed under the name by which it was first validly described, at whatever rank. Such citation does not imply approval of the appropriateness of the rank in question, and is designed primarily to lead the reader to a more detailed description.

Apart from this supposedly ecotypic variation, the pattern of variation of other characters in the genus is so reticulate and complex that there is great lack of agreement on the limits of species. The critical tradition of Central Europe has led to the recognition of a larger number of narrowly-defined species; in Northern Europe most recent authors have defined the species much more widely. This account attempts a compromise between the two traditions.

In Rhinanthus the recurrent ecotypic variants are as follows:

(1) Autumnal. Branches numerous, patent or arcuate; internodes numerous, short; intercalary leaves several. Late-flowering.

(2) Aestival. Branches usually 2-4 pairs, usually flowering; internodes numerous, usually short; intercalary leaves 0-2 pairs. Mid-season-flowering.,

(3) Vernal. Branches few or absent, short, non-flowering; internodes few, long; intercalary leaves absent. Early-flowering.

(4) Montane. Rather dwarf; branches few or absent; internodes short, fairly numerous; intercalary leaves variable in number. Mid-season-flowering.

(5) Alpine. Dwarf; internodes numerous, short; intercalary leaves several. Mid-season- to late-flowering.

Literature: A. Chabert, Bull. Herb. Boiss. 7: 497-517 (1899). D. J. Hambler, Watsonia 4: 101-116 (1958). R. von Soó, Feddes Repert. 26: 179-219 (1929); Acta Bot. Acad. Sci. Hung. 16: 193— 206 (1970). J. von Stemeck, Abh. Zool.-Bot. Ges. Wien 1(2): 1-150 (1901).

1 Teeth of upper lip of corolla less than 1 mm, rounded; corollatube straight (Sect. Rhinanthus )

2 Leaves and bracts deeply patent-dentate 1. groenlandicus 2 Most of the leaves and bracts crenate-serrate, with apically directed teeth 2. minor 1 Teeth of upper lip of corolla at least 1 mm; corolla-tube usually ±curved

3 Teeth of upper lip of corolla c. 1 mm long and wide, ± square (Sect. Brevirostres)

4 Bracts densely glandular-hairy

5 Leaves remotely patent-dentate; bracts much exceeding calyx, their upper teeth patent 4. wettsteinii 5 Leaves crenate-serrate; bracts scarcely exceeding calyx,

their upper teeth appressed 5. pubescens 4 Bracts glabrous or subglabrous

6 Throat of corolla open 3. asperulus 6 Throat of corolla ± closed

7 Corolla c. 18 mm 6. pindicus 7 Corolla c. 15 mm 7. antiquus 3 Teeth of upper lip of corolla l -5—2-5 x 0'5-l mm

8 Corolla with straight tube and convex margins to upper lip

8. dinaricus 8 Corolla with usually curved tube and concave margins to upper lip

9 Corolla with open throat and ± porrect teeth on upper lip

10 Teeth of bracts aristate, abruptly diminishing in length towards apex

11 Bracts and calyx glabrous 9. aristatus 11 Calyx and margin of bracts glandular-pubescent

10. pampaninii 10 Teeth of bracts not aristate, gradually diminishing in length towards apex

12 Bracts and calyx glabrous 11. alpinus 12 Bracts and calyx glandular-hairy 12. carinthiacus 9 Corolla with closed throat and patent teeth on upper lip

13 Calyx villous, though partly glabrescent in fruit.

25. alectorolophus 13 Calyx glabrous, puberulent or pubescent

14 Calyx distinctly and ± densely glandular-hairy, at least on the margin

15 Teeth at base of bracts longer and more crowded than those near apex 13. burnatii 15 Teeth of bracts subequal and equally spaced

16 Stem and upper bracts glandular-pubescent; surface of calyx glandular-pubescent even in fruit 14. rumelicus 16 Stem and upper bracts subglabrous; surface of calyx glabrous in fruit 15. wagneri 14 Calyx without glandular hairs, or rarely with a few on the margin

17Bracts and calyx eglandular-puberulent

18 Teeth of bracts abruptly diminishing in length towards apex 17. melampyroides 18 Teeth of bracts subequal, or gradually diminishing in length towards apex

19 Stem with black streaks; teeth of bracts gradually but conspicuously diminishing in length towards apex

16. mediterraneus 19 Stem without black streaks; teeth of bracts subequal in length 24. freynii 17 Bracts and calyx glabrous or scabrid (rarely sparsely glandular-puberulent on margin)

20 Teeth of bracts abruptly diminishing in length towards apex, the basal c. 8 mm

21 Bracts narrowly triangular, acuminate, much exceeding calyx 18. songeonii 21 Bracts triangular-ovate, acute, scarcely exceeding calyx 19. ovifugus 20 Teeth of bracts gradually diminishing in length towards apex, the basal c. 5 mm

22 Leaves acutely serrate or dentate

23 Bracts about equalling calyx 20. subulatus

23 Bracts much exceeding calyx 21. borbasii

22 Leaves crenate-serrate

24 Corolla 20-24 mm, golden-yellow; tube 5-7 mm

wide 22. halophilus

24 Corolla 16-20 mm, pale yellow; tube 2-3 mm wide

23. angustifolius