Flower heads arranged in cymes or rich thyrses, never several heads arranged one above the other, only exceptionally single heads seemingly sessile; inner bracts of the heads apically narrowly attenuate.

... question B

Inflorescence branched mostly at the base, its upper part normally consisting of series of heads arranged sympodially one above the other; inner bracts of the heads acute or slightly attenuate, but not with a long, slender apex.

... question E

Inner bracts widest in their lower half, basally acute or obtuse; corolla glabrous or with hairs of up to 1 mm.

... question C

Inner bracts widest near the middle or in their upper half, basally decurrent; corolla densely hirsute, the hairs 1-2(-3) mm long.

... question D

Corolla pale pink, its tube (2-)2.5-3.5 cm long, approximately funnel-shaped, glabrous or rarely with few, scattered hairs, the corolla lobes normally spreading forward.

Suessenguthia multisetosa

Corolla intensely pink, its tube 3.5-4.5 cm long, tubular, sparsely to densely hirsute; the corolla lobes slightly recurved to spreading at right angles with the tube.

Suessenguthia wenzelii

Internodes of the inflorescence with hairs up to 0.5 mm long; bracts with hairs up to 1 mm long; shrub.

Suessenguthia vargasii var. vargasii

Internodes of the inflorescence densely hirsute, the hairs 1.5-3 mm long; bracts with hairs 1-2 mm long; scrambling shrub with slender branches.

Suessenguthia vargasii var. hirsuta

The two outermost bracts of a head glabrous or sparsely hairy, always apically reddish, somewhat concave, slightly shiny and in most cases larger than the inner bracts; all anthers included, rarely one pair slightly exserted.

Suessenguthia barthleniana

The two outermost bracts of a head densely hairy, often smaller than the nearest inner bracts, dull, flat; if glabrous or only sparsely hairy and larger, the bracts are green and long-ovate, quite like an apetiolate, small leaf; all anthers at least at the mouth of the corolla tube, usually at least one pair exserted.

... question F

Heads excluding corollae (2.5-)3.0-4.0 cm long; corolla strongly pink, rarely pale white-pinkish, its lobes at most partly struck back, but not rolled back.

Suessenguthia trochilophila

Heads excluding corollae 2-3 cm long; corolla deep red, its lobes tightly struck back or rolled back, reduced.

Suessenguthia koessleri

Lower leaflet surfaces with sericeous indument, rarely almost glabrous with a few silky hairs restricted to veins

... question 2

Lower leaflet surfaces with woolly, pannose, villous, strigose, or small, matted, glandular indument, or glabrous (some species with sericeous hairs on leaflet margins)

... question 6

Hairs of lower leaflet surfaces dense, evenly covering the surface

... question 3

Hairs of lower leaflet surface confined to, or most prominent on, the veins

... question 4

Lower leaflet surfaces often with a layer of small, lanose hairs below the silky hairs; leaflet apices emarginate; 2–3(–4) pairs of leaflets

Polylepis lanuginosa Kunth

Lower leaflet surfaces lacking a lower layer of small hairs; leaflet apices obtuse to acute; (2–)5–7 pairs of leaflets

Polylepis sericea Wedd.

Leaflet apices acute; 4–9 pairs of leaflets

Polylepis pauta Hieron.

Leaflet apices emarginate; 1–3 pairs of leaflets

... question 5

Leaflets 0.6–1.3 cm long; fruits with irregular protuberances or blunt spines

Polylepis pepei Simpson

Leaflets 1.7–2.3 cm long; fruits with irregular flattened ridges

Polylepis subsericans Macbride

Lower leaflet surfaces glabrous or with very short pannose, matted, glandular hairs that are not recognizable as individual hairs with the unaided eye, hairs shorter than the height of the leaf veins; leaf veins glabrous or puberulous, easily visible

... question 7

Lower leaflet surfaces woolly, pannose, villous, lanose, or strigose, individual hairs recognizable with the unaided eye; leaf veins with similar hairs, often completely obscured by them

... question 13

Leaflets 1–4 pairs, membranaceous, sharply serrate; fruits with 2–3 thin wings

... question 8

Leaflets 1 pair, coriaceous, entire to crenate; fruits with 3–5 hard, irregular ridges

... question 9

2–12 flowers per inflorescence; 1–3 pairs of leaflets; stipular sheaths glandular or hispid; Argentina

Polylepis australis Bitter

14–27 flowers per inflorescence; 2–4 pairs of leaflets; stipular sheaths glabrous or hispid; Bolivia

Polylepis neglecta M. Kessler

Upper leaflet surfaces glabrous, covered by a yellow, glassy resin; leaflets 0.7–1.3 cm long, entire to very slightly crenate; western Cordillera of S Peru, N Chile, and W Bolivia

Polylepis taparacana Philippi

Upper leaflet surfaces without resin, glabrous to slightly pilose; leaflets 0.7–4.0 cm long, crenate; Ecuador to E Bolivia and NW Argentina

... question 10

Leaflet apices emarginate; leaflets 1.2–4.0 cm long; Ecuador and Peru

Polylepis incana Kunth

Leaflet apices obtuse to acute; leaflets 0.7–2.4 cm long; Bolivia and Argentina

... question 11

Plants shrubs, to 1.5 m tall; leaflets 0.7–1.2 cm long, with 5–6 teeth per side; inflorescences to 1.8 cm long, lacking glandular hairs; Prov. Arani, Dep. Cochabamba, Bolivia

Polylepis tomentella Wedd. subsp. nana M. Kessler

Plants shrubs or trees, to 9 m tall; leaflets 0.8–2.4 cm long, with 5–24 teeth per side; inflorescences to over 1.2 cm long, with or without glandular hairs; widespread in E Bolivia and NW Argentina

... question 12

Leaflets 0.9–2.4 cm long, with 7–24 teeth per side; leaflet apices obtuse to slightly acute; lower leaflet surfaces with or without yellow glandular hairs; upper leaflet surfaces glabrous, rarely very slightly pilose; 4–8 flowers per inflorescence; Dep. Cochabamba, Bolivia

Polylepis tomentella Wedd. subsp. incanoides M. Kessler

Leaflets 0.8–1.9 cm long, with 5–10 teeth per side; leaflet apices slightly to strongly acute; lower leaflet surfaces always with yellow glandular hairs; upper leaflet surfaces glabrous to pilose; 2–6 flowers per inflorescence; Deps. Potosν, Oruro, Chuquisaca, Tarija in Bolivia, NW Argentina

Polylepis tomentella Wedd. subsp. tomentella

Fruits with mostly 3–8 narrow spines; lower leaflet surfaces densely pannose or lanose, lacking yellow glandular hairs; leaflet apices emarginate; Colombia to NW Argentina

... question 14

Fruits with 3–5 irrugularly knobby or spiny ridges; lower leaflet surfaces woolly, pannose, villous, or strigose, often with yellow glandular hairs; leaflet apices emarginate to acute; Peru and Bolivia

... question 19

6–8 pairs of leaflets; inflorescences 15–35 cm long, with >20 flowers per inflorescence; N Peru

Polylepis multijuga Pilger

2–6 pairs of leaflets; inflorescences 3–12 cm long, with <20(–24) flowers per inflorescence; Colombia to NW Argentina

... question 15

Stipular sheaths and leaflet margins with sericeous hairs contrasting with the pannose hairs of the lower leaflet surfaces; 2–3 pairs of leaflets; Ecuador

Polylepis reticulata Hieron.

Stipular sheaths and leaflet margins with pannose or villous hairs resembling the hairs of the lower leaflet surfaces; 3–6 pairs of leaflets; Colombia to NW Argentina

... question 16

Outer surfaces of stipular sheaths with long, sericeous hairs; C Bolivia to NW Argentina

Polylepis hieronymi Pilger

Outer surfaces of stipular sheaths glabrous or with lanose hairs, sometime sericeous hairs emerging from the inner surfaces of the sheaths; Colombia to C Peru

... question 17

Upper leaflet surfaces rugose, occasionally with scattered long hairs; stipular sheaths apically obtuse; inflorescences 2.0–5.5 cm long, with 3–7 flowers; fruits with thin, terete spines; Colombia

Polylepis quadrijuga Bitter

Upper leaflet surfaces nitid, when young with long, shaggy hairs; stipular sheaths apically with acute spurs; inflorescences 5.5–14.0 cm long, with 8–18 flowers; fruits with flattened spines; Ecuador and Peru

... question 18

Lower leaflet surfaces and stipular sheaths villous intermixed with short, matted, dark red multicellular hairs; leaflets 0.4–0.9 cm long, in 4–6 pairs

Polylepis microphylla (Wedd.) Bitter

Lower leaflet surfaces and stipular sheaths pannose, lacking red hairs; leaflets 0.7–1.6 cm long, in 2–4 pairs

Polylepis weberbaueri Pilger

Lower leaflet surfaces with shaggy, lanose, long hairs restricted to the veins or much longer there than on the remaining surface; fruits usually with a large distal spine on each ridge

... question 20

Lower leaflet surfaces with homogeneously distributed, short to long, pannose to villous hairs; fruits usually with several spines

... question 22

Leaflets 2–3 pairs, apically obtuse to emarginate, marginally entire or with 4–8 teeth per side; inflorescence rachises loosely to densely villous; Dep. Cochabamba, Bolivia

Polylepis lanata (Kuntze) M. Kessler & Schmidt-Lebuhn

Leaflets 1–3 pairs, apically obtuse to acute, marginally with 8–14 teeth per side; inflorescence rachises with scattered, shaggy hairs; Peru to Dep. La Paz, Bolivia

... question 21

Inflorescences 4–11 cm long, with 3–11 flowers; leaf rachises with villous hairs, lacking yellowish glandular hairs; Deps. Cajamarca to Cuzco, Peru

Polylepis racemosa Ruiz & Pav.

Inflorescences 8–18 cm long, with 8–18 flowers; leaf rachises with villous and scattered yellowish glandular hairs; Dep. Puno, Peru, to Dep. La Paz, Bolivia

Polylepis triacontandra Bitter

Leaflets 2–4 pairs, round, ovate or obovate, apically obtuse to emarginate; lower leaflet surfaces with dense, white, pannose hairs; inflorescences, flowers and fruits with dense, white, pannose hairs

... question 23

Leaflets 1–3 pairs, oblong to elliptic, apically obtuse to acute; lower leaflet surfaces with loose to dense, white, yellowish or grayish hairs; inflorescences, flowers and fruits with loose to dense villous hairs

... question 26

Leaflets 2.0–3.4 cm long, obovate, apically obtuse to emarginate; fruits usually with a large distal spine on each ridge; Dep. Cochabamba, Bolivia

Polylepis lanata (Kuntze) M. Kessler & Schmidt-Lebuhn

Leaflets 1.1–2.3 cm long, round to ovate; fruits usually with several spines; SW Peru, NW Chile, Deps. La Paz and Cochabamba, Bolivia

... question 24

Upper leaflet surfaces strongly rugose; leaves and inflorescences virtually lacking yellow glandular hairs; SW Peru, NW Chile

Polylepis rugulosa Bitter

Upper leaflet surfaces slightly to moderately rugose; yellow glandular hairs present on inflorescences, leaf rachises and/or lower leaflet surfaces; Bolivia

... question 25

Leaflets 1–3 pairs; stipular sheaths lacking spurs or with weak spurs to 1 mm long; leaf rachises with dense, white pannose hairs and yellow, glandular hairs; lower leaflet surfaces with dense, white, pannose hairs, lacking yellow, glandular hairs; Dep. Cochabamba, Bolivia

Polylepis besseri Hieron.

Leaflets 2–3 pairs; stipular sheaths with weak spurs 1–2 mm long; leaf rachises with dense, white pannose hairs, lacking yellow, glandular hairs; lower leaflet surfaces with dense, white, pannose hairs and with yellow, glandular hairs, especially along the veins; Dep. La Paz, Bolivia

Polylepis pacensis M. Kessler & Schmidt-Lebuhn

Leaflets lanceolate to obovate, 1.9–4.9 cm long; lower leaflet surfaces with villous, shaggy, white hairs; inflorescences branched or unbranched, with 8–18 flowers

Polylepis triacontandra Bitter

Leaflets elliptic, ovate or obovate, 0.9–3.2 cm long; lower leaflet surfaces with pannose, short to long, white, yellowish or grayish hairs; inflorescences unbranched, with 3–12 flowers

... question 27

Leaflets with yellowish hairs; upper leaflet surfaces usually with fairly dense, appressed hairs; stipular sheaths with strigose to lanose hairs

... question 28

Leaflets with whitish or grayish hairs; upper leaflet surfaces usually glabrous or nearly so; stipular sheaths subglabrous or with sparse to dense pannose hairs

... question 29

Stipular sheaths with lanose hairs; leaflets 1–2 pairs; around Lake Titicaca

Polylepis incarum (Bitter) M. Kessler & Schmidt-Lebuhn

Stipular sheaths with strigose hairs; leaflets 1 pair, rarely 2 pairs; W Peru

Polylepis flavipila (Bitter) M. Kessler & Schmidt-Lebuhn

Leaflets 1–2 pairs, 1.3–3.2 cm long, obovate to rhombic; 4–12 flowers per inflorescence; fruits 0.6–1.6 x 0.9–1.3 cm, with coarsely indented ridges, green, brown or red; Deps. Potosν (SE), Chuquisaca and Tarija in Bolivia, Prov. Salta in Argentina

Polylepis crista-galli Bitter

Leaflets 1–3 pairs, 0.9–2.9 cm long, elliptic, lanceolate, ovate or obovate; 3–7 flowers per inflorescence; fruits 0.3–0.7 x 0.3–0.7 cm, with finely indented ridges, green or brown; Deps. Cochabamba and NW Potosν, Bolivia

Polylepis subtusalbida (Bitter) M. Kessler & Schmidt-Lebuhn