Sphyrospermum, Poeppig & Endlicher, 1835

Luteyn, James L. & Pedraza-Peñalosa, Paola, 2013, Nomenclature, taxonomy, and conservation of the neotropical genus Sphyrospermum (Ericaceae: Vaccinieae), including five new species for Colombia, Ecuador, and Peru, Phytotaxa 79 (1), pp. 1-29 : 5-6

Key to the species of Sphyrospermum

1. Leaves six or more times longer than broad ................................................................................................................ 2

– Leaves four or less times longer than broad ................................................................................................................ 3

2. Leaves narrowly lanceolate, 0.9–1.3 cm broad, long-acuminate; corolla 8.5–9 mm long, greenish-cream; stamens 10 ................................................................................................................................................................... S. revolutum

– Leaves linear, 0.2–0.8 cm broad, narrowly acute; corolla 5–6 mm long, pink to pinkish-white; stamens 5 ................ ............................................................................................................................................................. S. linearifolium

3. Flowers sessile; bracteole 1; corollas white .......................................................................................... S. sessiliflorum

– Flowers pedicellate; bracteoles 2; corollas white, pink, (dark or bright) red, maroon, yellow, or pale yellowish-green. [N.B.: S. dissimile may have very short pedicels, 1 mm long, but the length of the pedicel is variable within the same plant reaching up to 4(–8) mm long in some flowers and the corolla is dark red] ...................................................... 4

4. Plants with indumentum glutinose .......................................................................................................... S. glutinosum

– Plants with variable indumentum but not glutinose .................................................................................................... 5

5. Corolla tiny, equal to or less than 6.5 mm long ............................................................................................................ 6

– Corolla larger, equal or more than 7 mm long ........................................................................................................... 15

6. Flowers 4-merous ........................................................................................................................................................ 7

– Flowers 5-merous ...................................................................................................................................................... 10

7. Flowers haplostemonous .......................................................................................................................... S. buxifolium

– Flowers diplostemonous .............................................................................................................................................. 8

8. Leaves 0.5–1(–1.5) × 0.4–0.6(–0.8) cm; pedicel 3–6 mm long; corolla cylindric, 3.5–4 mm long ...... S. microphyllum

– Leaves (0.7–)1.5–4.2(–13) × (0.8–)1.5–2.5(–5) cm long; pedicel> 10 mm long and rarely as short as 5 mm; corolla urceolate or cylindric-urceolate, (4–)5–7(–12) mm long ............................................................................................ 9

9. Corollas bright yellow ..................................................................................................................... S. munchiqueense

– Corollas white or pinkish to bright red ......................................................................................................... S. buxifolium

10. Pedicels (5–) 7–25 mm long ....................................................................................................................................... 11

– Pedicels 1–4 mm long................................................................................................................................................ 12

11. Leaves thick-succulent and concave when fresh that somewhat hide the flowers, drying smooth to wrinkled and with the margin often strongly revolute; corollas pale yellowish-green; stamens alternately slightly unequal in length ........ ............................................................................................................................................................................ S. haughtii

– Leaves not succulent, flat and not hiding the flowers, not drying wrinkled or strongly revolute, margin slightly recurved at best; corollas white or pinkish to bright red; stamens equal in length ..................................... S. buxifolium

12. Leaves elliptic or lanceolate, 0.6–1 cm wide, apex blunt acute [N.B.: This is the only species in the genus known to have yellow berries] .......................................................................................................................... S. xanthocarpum

– Leaves elliptic, (0.6–) 1–2 cm wide, apex subrounded, rounded, or broadly obtuse [N.B.: The fruit color remains unknown for the species following this lead] ............................................................................................................ 13

13. Pedicel ca. 1 mm long; corolla ca. 4 mm long, hairs outside in distal 1/2–1/3 ....................................... S. spruceanum

– Pedicel 2.5–3.5 mm long; corolla 4.5–5.5 mm long, with hairs outside throughout.................................................. 14

14. Leaves elliptic; corolla campanulate, sparsely puberulent outside ............................................................ S. flaviflorum

– Leaves elliptic, lenticular, or almost rotund; corolla cylindric to slightly campanulate, sparsely pilose outside .......... ............................................................................................................................................................. S. rotundifolium

15. Corolla campanulate, the throat broad and spreading ................................................................................................ 16

– Corolla cylindric, urceolate or infundibuliform, the throat obviously contracted ..................................................... 17

16. Flowers 4-merous; pedicel 1–4(–8) mm long; leaves acute and without mucro; berry more or less quadrangular ...... ...................................................................................................................................................................... S. dissimile

– Flowers 5-merous; pedicel 10–15 mm long; leaves obtuse to bluntly or sharply acuminate, prominently setosemucronate, the mucro deciduous; berry ellipsoid .............................................................................. S. campanulatum

17. Corollas red with lobes blue-black (even when dry) ..................................................................................... S. sodiroi

– Corollas white, pink, or red, but without lobes blue-black or markedly contrasting in color ................................... 18

18. Leaves drying with the secondary veinlets clearly visible on both surfaces, the tertiaries raised but less prominent, lamina about as long as broad, base truncate ............................................................................................ S. muscicola

– Leaves drying with the secondary and tertiary veinlets relatively obscure on both surfaces, especially beneath, lamina noticeably longer than broad, base variable, rounded, subcordate, cuneate, or obtuse ................................................ 19

19. Pedicels 4–7 mm long; corollas 7–8 mm long ................................................................................................ S. buesii

– Pedicels (10–) 12–30 mm long; corollas (7–) 8–30 mm long ..................................................................................... 20

20. Corollas 7–8(–12) mm long ..................................................................................................................... S. buxifolium

– Corollas 10–30 mm long ........................................................................................................................................... 21

21. Corollas 4-merous; calyx lobes ca. 0.5–0.8 mm long................................................................................................ 22

– Corollas 5-merous; calyx lobes 1–1.6 mm long ........................................................................................................ 23

22. Leaves 1–3.5(–4.3) × 0.5–1.5(–1.8) cm; corolla infundibuliform; flowers usually conspicuously extending beyond the subtending leaf; calyx densely to sparsely puberulent .............................................................................. S. boekei

– Leaves (2.6–)3–7(–8.5) × (1.6–) 2.5–3.5 cm; corolla cylindric; flowers not extending beyond the subtending leaf; calyx usually glabrous .......................................................................................................................... S. grandifolium

23. Leaves elliptic to oblong-elliptic, 1–2 × 0.5–1.1 cm, apex broadly obtuse to rounded; corolla ca. 27–30 mm long..... .............................................................................................................................................................. S. dolichanthum

– Leaves narrowly ovate-lanceolate, 4–7 × 1.2–3 cm, apex bluntly to sharply long-acuminate; corolla 18–22 mm long. ...................................................................................................................................................................... S. lanceolatum