Stryphnodendron, Martius, 1837

Scalon, Viviane Renata, Paula-Souza, Juliana De, Lima, Alexandre Gibau De & Souza, Vinicius Castro, 2022, A synopsis of the genus Stryphnodendron (Fabaceae, Caesalpinioideae, mimosoid clade), Phytotaxa 544 (3), pp. 227-279 : 231-233

Key to the taxa of Stryphnodendron

1. Subshrubs bearing a well-developed, woody underground root-like system, rarely a shrub; fruit a follicle

2. Leaflets margin sparsely puberule at least near the base and the apex, upper surface glabrous, lower surface sparsely puberule with a denser indumentum along the midrib, near the base and the apex; tuft of trichomes on the lower surface of the leaflets present, unilateral ................................................................................................................................................................... 2. S. barbatulum

2’. Leaflets margin glabrous (except S. confertum , ciliate), both surfaces glabrous to rarely sparsely pubescent on the lower surface near the insertion of the secondary petiolule ( S. platyspicum ) or along the midrib ( S. confertum ); tuft of trichomes on the lower surface of the leaflets absent.

3. Branches, petioles, inflorescence rachis and fruits densely yellow-velutinous; leaflets margin ciliate; calyx ciliate throughout its extension..................................................................................................................................................................... 3. S. confertum

3’. Branches, petioles, inflorescence rachis and fruits usually glabrous, sometimes sparsely puberulous or sparsely pubescent to pubescent; leaflets margin glabrous; calyx glabrous or ciliate only at the apex of the lobes.

4. Leaflets mostly widely elliptic, (0.8–)1.2–2(–3.5) cm, subcoriaceous to coriaceous, nerves prominent and evident on both surfaces (usually up to the tertiary nerves)...........................................................................................................................24. S. platyspicum

4’. Leaflets mostly oblong or elliptic, (0.15–)0.3–0.7(–0.9) cm, chartaceous, nerves usually immersed to weakly prominent on the upper surface, inconspicuous and weakly prominent on the lower surface

5. Subshrubs 50–100 cm tall; calyx lobes ciliate at the apex; fruit 11–14 × 1–1.5 cm .................................................. 15. S. heringeri

5’. Subshrubs (25) 30–50 cm tall (except S. gracile which sometimes can reach up to 2m tall and show a shrubby habit); calyx lobes not ciliate; fruit (4.5–)5–9.5(–11) × 1.5–2.2 cm

6. Rachis nectaries 4; calyx campanulate, 1–1.5 mm long; corolla ca. 3 mm long, fused at 2/3 of its length; stamens ca. 5 mm long; endemic to Serra do Cipó (Minas Gerais state, Brazil).................................................................................................. 13. S. gracile

6’. Rachis nectary 1; calyx hypocrateriform, ca. 0.5 mm long; corolla ca. 4 mm long, fused at 1/2 of its length; stamens 7–8 mm long; endemic to Cristalina and Serra dos Cristais (Goiás state, Brazil)............................................................................. 6. S. cristalinae

1’. Shrubs, treelets or trees; fruit a nucoid legume (unknown in the arboreous S. holosericeum , S. procerum and S. orinocense )

7. Petiolar nectaries absent; one pair of nectaries present on the branch right below the insertion of the petiole (a nectary at each side)

8. Leaflets glabrous on both surfaces, very rarely the midrib sparsely pubescent on the lower surface; the base of leaflets usually asymmetrically cordate; peduncle (1.5–) 2–2.5 cm long; fruits curved to spiral ........................................................ 5. S. coriaceum

8’. Leaflets velutinous on the lower surface; the base of most leaflets weakly asymmetrically round; peduncle ca. 0.5 cm long; fruits cochleate.....................................................................................................................................................................9. S. fissuratum

7’. Petiolar nectaries present, usually at the base or sometimes at the middle part, rarely at the apex; nectaries in the branches absent

9. Pinnae 1–4 pairs in most leaves, leaflets 2–5 pairs, measuring at least 4.2 × 2 cm

10. Sinflorescence a diplothyrsus............................................................................................................................... 30. S. racemiferum

10’. Sinflorescence a pleiothyrsus (very rarely a diplothyrsus in S. occhionianum , but then the lower surface of the leaflets puberule or pubescent and corolla glabrous)

11. Petiolar and rachis nectaries lenticular-immersed; midrib of the leaflets’ lower surface glabrous........................... 19. S. moricolor

11’. Petiolar and rachis nectaries concave; midrib of the leaflets’ lower surface hairy

12. Lower surface of the leaflets glabrous, except for the puberulent to subglabrous midrib; fruit contorted forming a globose conglomerate .......................................................................................................................................................26. S. polystachyum

12’. Lower surface of the leaflets usually puberule, sometimes sparsely pubescent to pubescent; fruit curved, never forming conglomerate

13. Leaflets with apex usually apiculate, sometimes acute; calyx and corolla pubescent; mature fruit subturgid, without constriction between the seeds (not moniliform) ......................................................................................................................22. S. paniculatum

13’. Leaflets with apex usually round to sometimes obtuse, very rarely acute or truncate; calyx glabrous to subglabrous, usually with trichomes only at the apex of the lobes; corolla-tube glabrous, sometimes puberule at the apex of the lobes; mature fruit turgid, moniliform..........................................................................................................................................................20. S. occhionianum

9’. Pinnae (3–)5–18 pairs in most leaves, leaflets (5–)7–32 pairs; if 3 pairs of pinnae and 5 pairs of leaflets then the leaflets measuring up to 3 × 1.5 cm

14. Leaflets glabrous on both surfaces, except for the tuft of trichomes on the lower half of midrib or sparse trichomes along the midrib on the lower surface

15. Corolla pubescent throughout the tube and/or lobes

16. Petiolar nectary situated at the apex of the petiole; pinnae 3–4 pairs; rachis nectary 1, verruciform; leaflets (8)11–-18 × (6) 9–11 mm ....................................................................................................................................................................................17. S. levelii

16’. Petiolar nectary situated at the base of the petiole; pinnae (9–)11–16(–18) pairs; rachis nectaries 2–5, conicals; leaflets 3–9 × 1–3 mm ......................................................................................................................................................................29. S. pulcherrimum

15’. Corolla glabrous, usually only the apex of the lobes ciliate, rarely ciliate throughout the whole extension

17. Peduncle (0.5–) 2–2.5 cm; ovarium glabrous, floral prophyll deciduous; immature fruits flat, seeds not prominent; mature fruits turgid, seeds not prominent ...................................................................................................................................... 1. S. adstringens

17’. Peduncle (1.3–) 2.2–4.5 cm; ovary white-pubescent; floral prophyll early deciduous; immature fruits flat with prominent seeds, mature subturgid to flat with prominent seeds .................................................................33.1. S. rotundifolium var. rotundifolium

14’. Indumentum um of leaflets uniform throughout the blade, on one or both surfaces

18. Fruit valves conspicuously nerved

19. Pinnae 11–14 pairs; leaflets (5–)11–19 pairs, 4–11 × 2–6 mm; bilateral tuft of trichomes on the lower surface of the leaflets; fruits 9–14 cm long (endemic to Ecuador) ..........................................................................................................................27. S. porcatum

19’. Pinnae 6–9 pairs; leaflets (6–)8–10 pairs, (11–)13–24 × (6–) 7–19 mm; unilateral tuft of trichomes on the lower surface of the leaflets; fruits 5.4–8.5 cm long (endemic to Bolivia)..................................................................................................35. S. venosum

18’. Fruit valves smooth (not conspicuously nerved)

20. Calyx cup–shaped, without apparent lobes; if campanulate then the lobes irregular ...............................................14. S. guianense

20’. Calyx campanulate to campanulate-tubular, tubular, infundibuliform or hypocrateriform with regular lobes.

21. Most flowers with calyx densely yellow-pubescent to yellow-tomentose, and corolla tube glabrous, subglabrous to yellowsericeous, lobes puberule to (yellow-) pubescent (at least near the apex of the lobes).

22. Petiolar nectary inconspicuous, 1–1.2 × 0.5–0.8 mm, verruciform; floral prophyll early deciduous

23. Yellow-pubescent rachis with 1 nectary; yellow-pubescent corolla; glabrous ovary; fruits 1.6–2.2 cm wide ...........7. S. dryaticum

23’. Yellow-tomentose rachis with 3–5 nectaries; yellow-sericeous corolla; yellow-tomentose ovary; fruits 3–3.5 cm wide................... ....................................................................................................................................................................... 10. S. flavotomentosum

22’. Petiolar nectary conspicuous, (1–)2–4 × (1–) 1.5–2 mm, conical to verruciform with an elongated base (rarely only verruciform); floral prophyll deciduous to rarely late deciduous

24. Leaflets 15–28(–32) pairs in most pinnae, up to 3 mm wide, usually narrowly oblong, sometimes narrowly elliptic or lanceolate.. ............................................................................................................................................................................29. S. pulcherrimum

24’. Leaflets (5–)6–18 pairs in most pinnae, 4–15(–20) mm (if less than 4 mm wide, then 3–9 rachis nectaries, verruciform and measuring 0.5 × 0.5 mm), usually oblong, oblong–rhombic to rarely elliptic to elliptic-ovate.

25. Rachillae with 1–3 patelliform nectaries (0.5–0.8 × 0.2 mm), usually only between the distal pairs of pinnae; floral prophyll late deciduous...................................................................................................................................................................... 8. S. excelsum

25’. Rachillae with 1–3 conical nectaries (ca.1 × 1 mm), usually only between the 2–3 proximal pairs of pinnae) or (2–)4–12 verruciform nectaries (0.2 × 0.2 or 0.5 × 0.5 mm, between all pairs of pinnae); floral prophyll deciduous.

26. Treelets to trees 5–10 m tall; rachillae with 1–3 conical nectaries, ca. 1 × 1 mm (usually only at the 2–3 proximal pairs of pinnae) ....................................................................................................................................................................................... 4. S. conicum

26’. Treelets to trees (8–) 10–33 m tall; rachillae with (1–)2–9(–12) verruciform nectaries, 0.2 × 0.2 or 0.5 × 0.5 mm.

27. Pinnae (7–)9–12 pairs; leaflets with lower surface densely puberule to pubescent with a bilateral tuft of trichomes usually prolonged up to the middle part of the blade.........................................................................................................................12. S. glandulosum

27’. Pinnae 4–8 pairs; leaflets with lower surface usually subglabrous, sometimes sparsely puberule to puberule, unilateral tuft of trichomes (usually prolonged up to the 3 rd pair of basal nerves) present or absent to sometimes inconspicuous.

28. Rachis with 1–4 conical nectaries (ca. 1 × 1 mm); calyx shortly apiculate, not ciliate ............................................ 28. S. procerum

28’. Rachis with 1–3 nectaries, verruciform to verruciform with an elongated base (ca. 0.5× 1 mm); calyx apiculate, ciliate ................. .....................................................................................................................................................................................31. S. riparium

21’. Calyx usually glabrous to subglabrous, sometimes ciliate (at least at the apex of the lobes), rarely hirsute on the lobes or sparsely pubescent; corolla tube glabrous, lobes glabrous, subglabrous to very rarely hirsute (at least at the apex).

29. Branches densely villous, densely velutinous, velutinous to pubescent, sometimes glabrescent; flowers white, greenish to yellowish (if white then the calyx ciliate at least at the apex of the lobes). Central Brazil, in cerrado, c erradão, campo and rarely campo rupestre.

30. Petiolar nectary verruciform with an elongated base, 2–4 × 0.5–1(–1.5) mm; 2 nd degree petiolule of the leaflets (0.2–) 0.5–1 mm long, pubescent to villous; floral prophyll early deciduous ....................................................... 33.2 S . rotundifolium var. villosum

30’. Petiolar nectary fusiform, usually immersed, 3–4 × 0.5 mm; 2 nd degree petiolule of the leaflets 0.2–0.3 mm long, densely yellowvelutinous; floral prophyll deciduous to late deciduous.

31. Pinnae 5–6 pairs; leaflets 5–7 pairs; leaflets (11–)20–26 × (11–) 16–24 mm, velutinous on the upper surface, densely velutinous on the lower surface........................................................................................................................................................34. S. velutinum

31’. Pinnae (6–)9–10 pairs; leaflets (4–)6–11 pairs; leaflets (6–)8–13(–16) × (6–) 8–13 mm, villous to sericeous on both surfaces......... ............................................................................................................................................................................. 16. S. holosericeum

29’. Branches usually glabrous, sometimes sparsely pubescent, ferruginous-pulverulent, glabrescent; corolla usually pinkish, purple to reddish, rarely white (then the calyx lobes not ciliate). Amazonia, Atlantic Rainforest or Semideciduous Forests in Bahia and Minas Gerais states, Brazil.

32. Rachillae densely yellow-pubescent to yellow-pubescent, not glabrescent; lower surface of leaflets usually pubescent, rarely sparsely pubescent.

33. Pinnae 6–8 pairs; rachilla nectaries (1–)2–3, conical; spikes 4–6.5 cm long................................................................. 11. S. foreroi

33’. Pinnae (9–)10–18 pairs; rachilla nectaries 1(–2) or absent, verruciform; spikes (6–)8–12.5(–13.5) cm long.

34. Petiolar nectary 2 × 0.5–1 mm, verruciform with an elongated base; leaflets discolor, base strongly asymmetrical (except the distal pair), proximal side usually obtuse to round, distal side usually round; calyx lobes ciliate at the apex; corolla tubular (fused at 2/3 of its length), puberule only at the apex of the lobes; floral prophyll late deciduous ............................................ 32. S. roseiflorum

34’. Petiolar nectaries ca. 1 × 1 mm, verruciform; leaflets subconcolor, base slightly asymmetrical (except the distal pair), round, very rarely obtuse at the proximal side; calyx not ciliate; corolla campanulate (fused at ½ of its length), glabrous; floral prophyll deciduous............................................................................................................................................................... 25. S. polyphyllum

32’. Rachillae yellow-pubescent to pubescent, glabrescent, sparsely ferruginous-pulverulent to ferruginous-pulverulent; lower surface of leaflets puberule.

35. Rachillae nectaries verruciform, ca. 1 × 1 mm; corolla usually tubular, rarely tubular-campanulate, 3–3.5 mm long, (2/3 fused in a tube); stamens 5–6 mm long; floral prophyll late deciduous .................................................................................. 21. S. orinocense

35’. Rachillae nectaries usually conical, 1–2 × 1–1.5 mm (if verruciform then 0.5 × 0.5 mm); corolla campanulate, 2–2.5 mm long (1/2 fused in a tube); stamens 3–4 mm long; floral prophyll deciduous.

36. Petiolar nectary verruciform, ca. 1.5 × 0.5 mm; calyx glabrous, ciliate only at the apex of the lobes .................23. S. platycarpum

36’. Petiolar nectary conical, laterally flat, 3–5 × 1.5–2 mm; calyx usually glabrous, sometimes subglabrous, ciliate (very rarely sparsely pubescent)......................................................................................................................................................... 18. S. microstachyum