Geranium L.

1. Geranium L. View in CoL View at ENA 2

Herbs. Leaves more or less orbicular in outline, palmately (rarely ternately) lobed or divided, many or all of them basal; cauline leaves, if present, usually opposite near base of stem, but often alternate in inflorescence. Inflorescence cymose; ultimate peduncles usually 2-flowered. Flowers actinomorphic. Stamens all fertile, or rarely 3-5 reduced to staminodes. Stigmas 5, filiform. Mericarps usually dehiscent, separating from the base upwards, usually retaining outer part of style in the form of a long beak, of which the apex remains for a while attached to the central axis formed by the still coherent inner parts of all 5 styles.

In all European species, except where the contrary is implied

in the description, the basal leaves (to which the descriptions refer) have long petioles; the cauline leaves, if present, have progressively shorter petioles and lamina often with fewer lobes; all leaves bear rather short, appressed hairs on both surfaces; and the sepals are hairy, obtuse to subacute, and mucronate or aristate.

In the description below lobe is used to indicate a primary division of the leaf, segment a division of a lobe. Measurements of sepals refer to the fruiting condition, and include the arista. 1 Annual or biennial

2 Petals with conspicuous claw; sepals erect during flowering

3 Sepals keeled; leaves not deeply divided 36. lucidum 3 Sepals not keeled; leaves very deeply divided, so as to appear compound

4 Petals 9-13 mm; pollen orange; mericarps with rather few ridges 37. robertianum 4 Petals 5-9 mm; pollen yellow; mericarps with numerous ridges 38. purpureum 2 Petals without distinct claw; sepals ±patent during flowering

5 Petals entire 30. rotundifolium 5 Petals 2-lobed, emarginate or crenulate at apex

6 Mericarps (excluding style) glabrous

7 Uppermost leaves opposite; arista of sepal at least 2 mm

33. columbinum 7 Uppermost leaves alternate; sepals with short mucro

(c. 0-5 mm)

8 Plant greyish-green, densely pubescent; lowest leaf of inflorescence considerably exceeding the subtended peduncle, and with petiole considerably longer than lamina 31. molle 8 Plant green, sparsely or moderately hairy; lowest leaf of infloresence shorter than or slightly exceeding the subtended peduncle, and with petiole scarcely longer than lamina 32. brutium 6 Mericarps (excluding style) hairy

9 Mericarps transversely ridged, separating without a stylar beak 25. divaricatum 9 Mericarps without transverse ridges, and with long stylar beak

10 Sepals shortly mucronate; 3-5 stamens lacking anthers

33. pusillum 10 Most of the sepals with long arista; all 10 stamens with anthers

11 Leaves divided for c. 95 % of the radius, with ± linear segments

12 Peduncles shorter than subtending leaf 35. dissectum 12 Peduncles longer than subtending leaf 34. columbinum 11 Leaves divided for c. 75 % of the radius, with ovateoblong segments

13 Seeds yellowish-grey, with irregular, dark brown patches, almost smooth; cotyledons with deep lateral notches 26. bohemicum 13 Seeds uniformly brown, distinctly foveolate; cotyledons without lateral notches 27. lanuginosum 1 Perennial, often with conspicuous rhizome, tuber or woody stock

14 Petals with a distinct claw at least | as long as the limb

15 Stamens 8-10 mm, only slightly exceeding the sepals

16 Leaves all ± basal; petioles c. 5 mm 4. humbertii 16 Several cauline leaves present; petioles of basal leaves

100-200 mm 39. cataractarum 15 Stamens 14-22 mm, more than twice as long as the sepals

17 Lamina of basal leaves 4-10 cm wide, divided for 75-80 %

of the radius; lobes lanceolate, irregularly pinnatifid or incise-dentate 1. macrorrhizum 17 Lamina of basal leaves 2-5-4 cm wide, divided for 90 % of the radius; lobes cuneate, entire except for shortly 3-

toothed apex 2. dalmaticum 14 Petals with very short claw or none

18 Petals entire, apiculate, erose or very slightly emarginate 19 Petals spreading horizontally or deflexed; mericarps with

2-4 conspicuous ridges below the base of the style 20 Arista of sepal 4-6 mm 17. aristatum 20 Arista of sepal c. 1 mm 21 Petals 6-10 mm wide, patent or slightly deflexed 15. phaeum 21 Petals 2-5-4 mm wide, sharply deflexed 16. reflexum 19 Petals curving upwards, giving a ± cup-shaped flower;

mericarps smooth, or with a single, indistinct ridge 22 Inflorescence compact, somewhat corymbose, with usually more than 10 flowers 23 Pedicels deflexed during maturation of the fruit; sepals

11-15 mm 7. pratense 23 Pedicels erect during maturation of the fruit; sepals

6-12 mm 8. sylvaticum 22 Infloresence diffuse, not corymbose, with usually less than 10 flowers 24 Petals c. 6 mm 28. sibiricum 24 Petals at least 12 mm 25 Rhizome long, slender, horizontal 9. endressii 25 Rhizome short

26 Roots fleshy, fusiform, arising in a cluster from a very short rhizome; arista of sepals not more than

1-25 mm 22. asphodeloides

26 Roots fibrous, not clustered; arista of sepals usually more than 1-5 mm

27 Sepals hairy only on the veins 23. palustre

27 Sepals hairy both on and between the veins

24. collinum 18 Petals 2- or 3-lobed, or distinctly emarginate 28 Stock small and inconspicuous; petals not more than

10(—12) mm 29 Mericarps smooth, hairy 30 Leaf-lobes cuneate, truncate; hairs on mericarp appressed 29. pyrenaicum 30 Leaf-lobes lanceolate, acute; hairs on mericarp patent

28. sibiricum 29 Mericarps rugose, glabrous 31 Plant greyish-green, densely pubescent; lowest leaf of inflorescence considerably exceeding the subtended peduncle, and with petiole considerably longer than lamina 31. molle 31 Plant green, sparsely or moderately hairy; lowest leaf of inflorescence shorter than or only slightly exceeding the subtended peduncle and with petiole scarcely longer than lamina 32. brutium 28 Plant with conspicuous tuber, rhizome or woody stock;

petals usually more than 10 mm 32 Peduncles 1-flowered 6. sanguineum 32 Peduncles 2-flowered 33 Pedicels with long glandular hairs 34 Leaves divided to the base 18-21. tuberosum group 34 Leaves divided for 65-80 % of the radius

35 Leaf-segments acute; sepals 5-7 mm; petals usually white 12. albiflorum

35 Leaf-segments obtuse; sepals c. 10 mm; petals bluishviolet 13. peloponesiacum 33 Pedicels eglandular, or with subsessile glands (sometimes also with much longer eglandular hairs) 36 Leaves not more than 4 cm wide, usually all basal

37 Leaves silvery-sericeous on both sides, with linearoblong segments 5. argenteum

37 Leaves green, at least above, with broadly oblong to suborbicular segments 3. cinereum 36 Larger leaves at least 5 cm wide, some of them cauline

38 Pedicels with subsessile glands

39 Petals c. 16 mm, pale lilac with darker veins

10. versicolor

39 Petals c. 25 mm, deep purple 14. ibericum

38 Pedicels eglandular

40 Rhizome long, slender; leaves divided for c. 70 % of the radius 11. nodosum

40 Rhizome short, often tuberous; leaves divided to the base 18-21. tuberosum group