Syagrus, Martius, 1824

Noblick, Larry R., 2017, A revision of the genus Syagrus (Arecaceae), Phytotaxa 294 (1), pp. 448-450 : 448-450

Key to Syagrus

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- Plants erect with an above ground stem................................................................................................................................ 2. Plants without an above ground stem or only a very short or prostrate stem ..................................................................... 38. Stems clustering .................................................................................................................................................................... 3. Stems solitary .......................................................................................................................................................................11.

CLUSTERING PALMS WITH ERECT ABOVE-GROUND STEMS

3. Leaflets regularly or evenly arranged along the rachis ............................................................................... Syagrus ruschiana

- Leaflets arranged in clusters of 2–5 along the rachis, especially near the base .................................................................... 4.

4. Leaflets all deflexed (bent downwards) .......................................................................................................... Syagrus deflexa

- Leaflets in slightly different planes, but not all deflexed...................................................................................................... 5.

5. Stems usually two, twins, occasionally 4 or clustered; mature fruit broadly flattened at tip and covered with brownish lepidote scales; seed often with a central cavity ............................................................................................... Syagrus cearensis

- Stems usually clustering, more than two; mature fruit rounded or tapering at the tip and glabrous or only sparsely lepidote; seed solid, without a central cavity ....................................................................................................................................... 6.

6. Inflorescence unilaterally branched (rachillae all on one side)............................................................................................. 7.

- Inflorescence spirally branched (rachillae on all sides) ........................................................................................................ 9.

7. Leaflets flexible more or less membranaceous, pendant at the tips .............................................................. Syagrus flexuosa

- Leaflets stiff, thick, and more or less leathery, straight or only slightly pendant at the tips................................................. 8.

8. Leaflet blades green or pale green abaxially, Minas Gerais ...................................................................... Syagrus campestris

- Leaflets blades white waxy abaxially, endemic to Bahia ........................................................................ Syagrus cataphracta

9. Stems 12–18 cm in diameter and 15 m tall (endemic to Venezuela) ....................................................... Syagrus stenopetala

- Stems 5–8 cm in diameter to 4 m tall.................................................................................................................................. 10.

10. Middle leaflets ca. 3 cm wide, fruit nearly globose, deeply grooved ( Guyana, Suriname, French Guiana, Amapa, Brazil?) ............................................................................................................................... ................................... Syagrus stratincola

- Middle leaflets 1.5–2 cm wide, fruit ovoid, smooth, and less than 2.5 cm in diameter (endemic to western Bolivia) ........... ............................................................................................................................... ..................................... Syagrus cardenasii

A REVISION OF THE GENUS SYAGRUS

Phytotaxa 294 (1) © 2017 Magnolia Press • 15

SOLITARY PALMS WITH ERECT ABOVE-GROUND STEMS

11. Pseudopetiole margins with well-defined teeth along its margins...................................................................................... 12.

- Pseudopetiole margins nearly smooth, with flexible or rigid fibers, but no teeth............................................................... 13.

12. Leaflets 18–50, rachillae 8–32, fruits not splitting at tips, endosperm ruminate at least at the margins with an intruded seed coat ............................................................................................................................... ........................... Syagrus schizophylla

- Leaflets 70–90, rachillae 43–62, fruits split at tips, endosperm homogeneous ............................................. Syagrus santosii

13. Leaflets deflexed (bent downwards) ............................................................................................................... Syagrus deflexa

- Leaflets in different planes or nearly in one plane, but not all deflexed ............................................................................. 14.

14. Leaflets evenly distributed along each side in one plane .................................................................................................... 15.

- Leaflets in clusters of 2–5 along each side usually in various planes................................................................................. 18.

15. Leaflets glabrous abaxially, both sides of the leaf forming a V-shape, and leaf rachis recurved ........... Syagrus botryophora

- Leaflets covered with silvery or fine light brownish pubescence abaxially, arranged regularly in one plane, with both sides of leaf lying in the same plane, and more or less straight ................................................................................................... 16.

16. Leaflets covered with usually a brownish pubescence adaxially, leaf rachis 140–155 cm, leaflets 1.5–2.0 cm wide, fruit with ruminate endosperm ............................................................................................................................... Syagrus hoehnei

- Leaflets covered with a silvery pubescence abaxially, leaf rachis to 99 cm, leaflets 0.4–1.5 cm wide, fruit with homogeneous endosperm ................................................................................................................................................................. 17.

17. Stem to 10 m, leaf sheath and leaf rachis covered with fine black fibers, eophyll simple lanceolate, continuing to produce simple lanceolate leaves for the first 30 cm ................................................................................................... Syagrus insignis

- Stem to 1–3.5 m, leaf sheath and leaf rachis covered with fine dark brownish to chestnut colored fibers, eophyll very small and simple lanceolate, but second leaf and thereafter are pinnate .......................................................... Syagrus weddelliana

18. Rachillae devoid of flowers at the tips; the naked tips folded back and forth like dried ramen noodles................................. ................................................................................................................................................................ Syagrus vermicularis

- Rachillae flowering to the tip; straight or only slightly twisted.......................................................................................... 19.

19. Leaf bases in vertical or spiraled rows on the stem ............................................................................................................ 20.

- Leaf bases not in rows; leaves spirally arranged................................................................................................................. 22.

20. Pseudopetiole margins with very wide, stiff, flat woody fibers................................................................... Syagrus coronata

- Pseudopetiole margins with thinner, narrower, more flexible fibers .................................................................................. 21.

21. Stem usually erect, pistillate flowers 10–17 mm long, fruit ellipsoid, 2–3 cm long, endocarp ellipsoid to ovoid, 2–2.8 cm long, 2–4 mm thick on its sides ............................................................................................................... Syagrus glaucescens

- Stem usually prostrate (occasionally erect), pistillate flowers 17–25 mm long, fruit globose, 3–4 cm long, endocarp nearly globose, 2.8–3.5 cm in diameter, 5–8 mm thick on its sides ........................................................................... Syagrus duartei

22. Pistillate flowers large, 16–35 mm long.............................................................................................................................. 23.

- Pistillate flowers small, 5–15 mm long............................................................................................................................... 28.

23. Inflorescence spicate or bifid (1 or 2 rachillae), fruit with longitudinal grooves ............................................... Syagrus elata

- Inflorescence with more than 15 rachillae, fruit smooth without grooves.......................................................................... 24.

24. Leaflets mostly straight and rigid, fruits 3.5–5.0 cm long .................................................................................................. 25.

- Leaflets mostly curled or pendulous, fruits 5.5–9.0 cm long.............................................................................................. 27.

25. Pistillate flower petals terminating in a long tapering valvate tip, fruit mostly glabrous, scale or short hairy indument present only at the tip .......................................................................................................................................... Syagrus oleracea

- Pistillate flowers abruptly terminating in a short valvate tip, fruits mostly covered by a fine lepidote scale or indument ..... ............................................................................................................................................................................................. 26.

26. Stems in twos, fours or clustered, but occasionally solitary, fruit nearly globose, broadly flatted at tip ... Syagrus cearensis

- Stems always solitary, fruit ovoid, rounded to tapered at tip ........................................................................ Syagrus kellyana

27. Pistillate flowers rounded, globose, fruits globose, 5.5–6.8 cm long, endocarp globose with smooth surface, endocarp tip with broad conical "Chinese-like cap"; endosperm ruminate ................................................................ Syagrus pseudococos

- Pistillate flowers pyramidal or elongate conical, fruit ellipsoid 6.5–9.0 cm long, endocarp ellipsoid with rough surface, endocarp tip with 3 ridges that begin at the tip and often continue down the sides; endosperm homogeneous ...................... ............................................................................................................................... .................................. Syagrus macrocarpa

28. Pistillate flowers 7 mm long or less, endocarpal wall irregular and penetrating the seed or endosperm, irregular in cross-section .................................................................................................................................................. Syagrus romanzoffiana

- Pistillate flowers usually 5–15 mm long, endocarpal wall smooth, triangular or circular in cross-section, but not irregular. ............................................................................................................................................................................................. 29.

29. Endocarp cavity more or less triangular in cross-section.................................................................................................... 30.

- Endocarp cavity more or less circular in cross-section ....................................................................................................... 31.

30. Pistillate flowers 11–13 mm long, anthers 5–6 mm long, fruits 5–8 cm in length, seeds with ruminate endosperm especially near its outer surface ......................................................................................................................................... Syagrus smithii

- Pistillate flowers 5–8 mm long, anthers 2.5–4 mm long, fruits 3.0– 5.5 cm in length, seeds with homogeneous endosperm. ........................................................................................................................................................................... Syagrus inajai

31. Rachillae 1–20..................................................................................................................................................................... 32.

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- Rachillae usually more than 20 ........................................................................................................................................... 33.

32. Stem smooth, more or less self-cleaning, peduncular bract thin 1–3 mm thick, fruit ovoid to pear-shaped, 3.5–6 cm long .. ....................................................................................................................................................................... Syagrus cocoides

- Stem rough or with persistent leaf bases, peduncular bract thicker 2.5–7 mm thick, fruit ellipsoid, 2–3 cm long ................. ........................................................................................................................................................................ Syagrus comosa

33. Leaves strongly ascending, fruit 2.5–3 cm long; mostly covered with a fine lepidote....................... Syagrus lorenzoniorum

- Leaves horizontal to spreading and pendulous, fruit 3 cm long or more; more or less glabrous ....................................... 34.

34. Fruits 4.1–7 cm long, endosperm ruminate with seed coat penetrating the margins of the endosperm (Eastern Caribbean). ............................................................................................................................... ........................................... Syagrus amara

- Fruits 3–4.5 cm long, endosperm homogeneous (South American)................................................................................... 35.

35. Stem rough, leaf scars closely spaced with little or no internodes, fruits only 1 or 2 per rachilla.......... Syagrus yungasensis

- Stem relatively smooth with distinct internodes, fruits many more than 2 per rachilla...................................................... 36.

36. Rachis of inflorescence usually more than 50 cm long, rachillae 78–180 or more, Andean foothills ......... Syagrus sancona

- Rachis of inflorescence less than 50 cm long, less than 70 rachillae.................................................................................. 37.

37. Leaflets more or less rigid and straight, pistillate flowers ca. 15 mm long; fruit often splitting at its tip, Atlantic Forest ..... ............................................................................................................................... ................................... Syagrus picrophylla

- Leaflets more or less pendulous, pistillate flowers 5–9 mm long; fruits not splitting at their tips, Amazonian...................... ............................................................................................................................... ................................... Syagrus orinocensis

SHORT and SUBTERRANEAN or PROSTRATE STEMMED PALMS

38. Leaflet blades covered with silvery pubescence abaxially, fruits red to reddish-orange, small 1.0–1.3 × 0.6 –0.7 cm .......... ................................................................................................................................................................. Syagrus itapebiensis

- Leaflets blades glabrous to waxy abaxially, fruits green, brown, yellow, orange, and larger than above .......................... 39.

39. Leaflet tips with hardened spines ....................................................................................................... Syagrus campylospatha

- Leaflet tips acute, acuminate, asymmetric, emarginate, but not with spines ...................................................................... 40.

40. Leaflets all deflexed (bent downwards) .............................................................................................................................. 41.

- Leaflets in one plane or in various planes but not all deflexed ........................................................................................... 43.

41. Leaflets in clusters of two along the rachis; rachillae gnarled and nodose, 0.5–0.7 cm long .................... Syagrus pleioclada

- Leaflets evenly arranged along the rachis; rachillae straight, 3 cm long or more .............................................................. 42.

42. Rachilla 1, peduncle 10–20 cm long, inflorescence axis 3–14 cm long ............................................. Syagrus pleiocladoides

- Rachillae 5–31, peduncle usually longer than 40 cm; inflorescence axis longer than 18 cm .................................................. ................................................................................ Syagrus harleyi (lower elevation form with strongly pendulous leaflets)

43. Leaves gray-blue, silvery-blue or silvery-green.................................................................................................................. 44.

- Leaves various shades of light to dark green or dark blue-green........................................................................................ 47.

44. Leaflets usually 0.3–0.8 cm wide ........................................................................... Syagrus graminifolia subsp. graminifolia

- Leaflets usually 0.9–3 cm wide........................................................................................................................................... 45.

45. The two sides of the leaf forming a V, proximal leaflets irregularly arranged along the rachis in clusters of 2 and sometimes 1 or 3, middle leaflets usually longer than 40 cm ........................................................................................ Syagrus pimentae

- Two sides more open and not forming a strong V, proximal leaflets irregularly arranged along the rachis in clusters of 3–5, middle leaflets usually 10–34 cm long............................................................................................................................... 46.

46. Leaf rachis 29–62 cm long, middle leaflets 10–22 cm long, pistillate flowers 5–7 mm long (Bahia) ... Syagrus microphylla

- Leaf rachis 70–120 cm long, middle leaflets 24–34 cm long, pistillate flowers 16–20 mm long (Goiás) ... Syagrus rupicola

47. Conspicuous whitish waxy bloom on abaxial side of the younger leaflets......................................................................... 48.

- Green or pale green adaxially but lacking waxy bloom or bloom not that conspicuous on underside of younger leaflets..... ............................................................................................................................................................................................. 54.

48. Middle leaflet tip usually emarginate and symmetrical ............................................................................. Syagrus evansiana

- Middle leaflet tip asymmetrical, obtuse, oblique, often one half acuminate and the other half obtuse.............................. 49.

49. Inflorescence usually branched; rachillae 4–9 .................................................................................................................... 50.

- Inflorescence spicate or rarely branched; rachillae 1 or rarely 2 ....................................................................................... 51.

50. Middle leaflets 29–66 cm long (Southwestern Goiás) ............................................................................. Syagrus menzeliana

- Middle leaflets 11–25 cm long ( São Paulo to Mato Grosso do Sul) ........................................................... Syagrus loefgrenii

51. Leaflets with prominently raised adaxial transverse veins, white lepidote waxy scales abaxially on younger leaves............ ...................................................................................................................................................................... Syagrus pompeoi

- Leaflets with inconspicuous adaxial transverse veins, solid whitish waxy bloom adaxially on young leaflets ................ 52.

52. Leaflets stiff, coriaceous, leaflets congested along the rachis, 40–112, bluish to silvery waxy on the abaxial surface (Goiás, Brazil) ............................................................................................................................... ...................... Syagrus caerulescens

- Leaflets more membranaceous, clustered or separated but not congested, 19–47, glaucous waxy only on abaxial surface... ............................................................................................................................................................................................. 53.

53. Middle leaflets 12–20 cm long, pistil whish pubescent on lower 1/3, ca. 7.5 mm long (central Brazil)................................. ............................................................................................................................................................ Syagrus allagopteroides