Geranium L.

Volume IV (1988) - Flora of New Zealand Naturalised Pteridophytes, Gymnosperms, Dicotyledons

GERANIUM L.

Annual, biennial or perennial herbs, sometimes with a caulorrhiza (woody rhizome or root stock), occasionally with small erect trunk, generally aromatic. Basal lvs often rosette-forming, long-petiolate, stipulate, palmately veined, lobed or compound, usually ovate to rounded or reniform. Cauline lvs similar to basal, with petiole becoming shorter, opposite near base, usually alternate above. Fls actinomorphic, single or paired, usually in cymose, bracteate, and pedunculate infls. Sepals 5, imbricate, spurless. Petals 5; claw prominent to almost 0. Fertile stamens usually 10, rarely 5 reduced to staminodes, free or nearly so, the outer antipetalous. Nectar glands 5. Ovary 5-lobed, usually with long style; ovules 2 per loculus. Fr. with long beak, the outer part of style separating into 5 long awns which generally remain attached to the mericarps, curving upwards but never twisted. Mericarps 1-seeded, sometimes releasing seed, lacking apical pits.

Key

Annuals, biennials, occasionally short-lived perennials, usually with thin fibrous tap roots, or if roots stout then plant large and monocarpic; glandular hairs prominent on infl.; fls white, mauve, pink, rose or crimson

Perennials with rather stout to tuberous caulorrhiza; stems usually slender and prostrate to sprawling; glandular hairs 0, very few or short and inconspicuous on infls and fls white to pink, or if glandular hairs present on infls then fls large and blue

Sepals usually erect and connivent at apex, if spreading then plant monocarpic and developing short trunk; petals with conspicuous claw > ⅓ length of limb or, if < ⅓, then petals > 12 mm long

Sepals ± spreading and not connivent at apex; plant never monocarpic with stout stem; petals < 7 mm long, with short inconspicuous claw

Petals < 12 mm long; anthers yellow or orange; mericarps 2.5-3 mm long

Petals 12-25 mm long; anthers pink or dark purplish; mericarps > 3.5 mm long

Petals usually 10-11.5 mm long; anthers orange

7. *robertianum

Petals 6-9 mm long; anthers yellow

5. *purpureum

Annual, biennial, or occasionally a short-lived perennial with slender sprawling or ascending stems; infl. very diffuse, slightly viscid with white glandular hairs

8. *rubescens

Plant usually monocarpic with short, stout, ± erect trunk; infl. a large dense, rounded panicle, very viscid with purple glandular hairs

2. *maderense

Mericarps glabrous on outer face, ridged

3. *molle

Mericarps hairy on outer face, smooth

Lvs, at least lower ones, divided nearly to base, with linear segments; sepals with awn 0.8 mm long; stamens 10, all fertile

1. *dissectum

Lvs, at least lower ones, divided to c. 3/4 way, with oblong to ovate segments; sepals with mucro < 0.5 mm long; stamens 10, 4-5 reduced to staminodes (lacking anthers)

6. *pusillum

Basal lvs > 8 cm wide; infl. covered in conspicuous glandular hairs; petals > 17 mm long, blue

4. *pratense

Basal lvs < 8 cm wide, usually much less; infl. with inconspicuous, very short glandular hairs (simple hairs may be prominent); petals < 15 mm long, white, pink, or rose

Lvs covered with ± silvery hairs; corolla 20-25 mm diam.

15 traversii

Lvs variously hairy, but not appearing silvery; corolla < 15 mm diam.

Basal lvs nearly always < 3 cm diam.; fls generally single, sometimes in pairs; seed coat smooth or with alveolae very shallow

Basal lvs mostly > 3 cm diam.; fls usually in pairs; seed coat alveolae rather shallow to deep

Flowering stems usually very short and < basal lvs; seed smooth

13 sessiliflorum

Lvs greyish with dense appressed hairs

var. arenarium

Lvs green, bronze, or purple, glabrescent to hirsute

var. novaezelandiae

Flowering stems to 6-(9) cm long, often > basal lvs; seed reticulate or smooth

Seed smooth, rarely finely reticulate; petals white; sepals with at least some appressed hairs (especially in the distal 1/2), or if spreading hairs present then these generally ± glandular; sepal margins usually with narrow purple line

10. microphyllum

Seed distinctly alveolate; petals pink; sepals with spreading, eglandular hairs, with ± green margins

11. potentilloides

Median teeth of lf lobes about as long as broad; sepals mostly elliptic to obovate; hyaline border of inner sepals mostly > 0.3 mm wide near apex; seed red-brown, with alveolae rectangular and rather shallow

9. homeanum

Median teeth of lf lobes mostly longer than broad; sepals ovate; hyaline border of inner sepals mostly < 0.3 mm wide near apex; seed red-brown to dark brown, with alveolae rectangular to polygonal and rather deep

Lf lobes usually linear-obovate; hairs of petioles and pedicels sharply bent near base, retrorse and appressed; alveolae of seed ± isodiametric, c. 0.1 mm diam.

12 retrorsum

Lf lobes obovate; hairs of petioles and pedicels straight to curved, perpendicular to retrorse, never appressed; alveolae of seed isodiametric to rectangular, usually > 0.1 mm diam.

14 solanderi

300-400 spp., temperate and subtropical regions, also montane tropical regions. Native spp. 7, naturalised 8.

In addition to those described below, a number of N. Hemisphere spp. are cultivated in N.Z.; several are very common as rock garden, rock wall or embankment plants. These are perennial, often mat-forming, and all have lvs palmately lobed to some degree. The commonest is G. sanguineum L., bloody cranesbill, a mat-forming plant with very dissected, narrowly lobed lvs and large, solitary fls with crimson-magenta or pink petals c. 15 mm long. It persists in many long-abandoned gardens. In the descriptions below the length of lf lobes refers to the axis of the longest central lobes.

Fls of some geraniums are illustrated in Fig. 72.

Fig. 72. Fls of Geranium. A G. maderense; B G. pratense; C G. purpureum; D G. robertianum; E G. rubescens. © All rights reserved. [Image: 4X5Z]

Geranium L.

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