Syagrus pimentae Noblick, 2017

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

46. Syagrus pimentae Noblick sp. nov. Type:— BRAZIL. Mato Grosso: Rondonópolis, BR: 163, km: 90, Habitat: Cerrado ; solo: argissolo vermelho-amarelo. Elevation ca. 220 m, –16.66, –54.68; 21 August 2010, Ricardo Pimenta & Antonio Campos-Rocha s.n. (holotype HPL! [HPL-13801], isotypes FTG!, K, RB)

Diagnosis:— Palm 0.8–1.2 m tall; stem short and subterranean; leaves spreading, silvery-bluish to silvery-greenish, leaflets evenly spaced and lying in more or less one plane, but in clusters of 2 or 3 at the base, with the two sides of the leaf forming a V-shape, similar in appearance to leaves of the genus Butia ; leaflets have a dorsal-ventral asymmetric arrangement of the vascular tissue and fiber bundles (not mirrored as in Butia ); peduncular bract deeply sulcate.

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NOBLICK A REVISION OF THE GENUS SYAGRUS

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Figure 64 plate, Figure 65 map.

Small solitary palm 0.8–1.20 m tall. Stem short, subterranean with a rhizome. L EAVES 5–8, usually spreading; sheathing leaf base ca. 21–24 × 1.2–1.4 cm with fibrous margins; pseudopetiole 14–40 cm long, petiole 5.5–17 × 0.8–1.3 cm, 0.5–0.7 cm thick; rachis 44–65 cm long, one side of the leaf forming a V shape with the other side similar to a Butia leaf; leaflets silvery bluish-green, slightly lighter on the abaxial surface, 16–22 along each side, mostly regularly arranged near the apex, but proximal leaflets irregular, clustered 2 or 3 near the base, no ramenta scales or tomentum present where the leaflets are inserted on the rachis nor any along the abaxial midvein; basal leaflets 28–44 × 0.1–0.3 cm, middle leaflets 38–58 × 0.8–1.1 cm, apical leaflets 26–35 × 0.1–0.2 cm with an acuminate tip. Inflorescence spicate, prophyll ca. 8.5–12 × 2.5–3.5 cm; fibrous; peduncular bract ca. 23–31 cm long, expanded portion 15–18.5 × 3.5–4.0 cm, 6.5–8.0 cm perimeter, 4 mm thickness, woody, sulcate, exterior with a few scattered scales; peduncle ca. 9.5–17 cm × 5–7 mm, glabrous; inflorescence axis 9–10 cm long; rachis absent; rachilla 1, glabrous, 9–10 cm long; staminate flower 10.2 mm at the apex, 11.3–15.0 mm at the base, green to yellow, sepals 1.3–1.5 × 1.0– 1.5 mm, glabrous, no visible nerves, petals 8.4–9.5 mm at the apex, 8.8–12.6 mm at the base with acute tips, nerves indistinct, stamens 5.1–6.6 mm long, anthers 3.7–5.1 mm long, filaments 2.2 mm long, pistillode, ca. 0.7 mm long; pistillate flowers pyramidal, 12.4–13.2 mm long near the apex, 13.5–15.3 × 6.6– 9.1 mm near the base, yellow, glabrous, sepals 9.5–13.2 × 3.7–6.6 mm, glabrous, no visible venation, petals 9.9– 13.5 × 4.75–7.0 mm, glabrous, obscurely nerved, valvate tips 1/2 or more the length of the petals, ca. 5–8 mm long, pistil 5.8–7.3 mm long, glabrous, stigmas ca. 3 mm long, glabrous, staminodal ring ca. 0.7–1.1 mm high, truncate to undulate. Immature Fruit nearly globose, 2.0 × 1.6 cm, brownish, epicarp less than 0.5 mm thick, mesocarp not measured, succulent and fibrous; endocarp nearly globose, 1.6 × 1.4–1.5 cm, thickness not measured; seed ellipsoid not measured, endosperm homogeneous. Germination remote-tubular.

Common name:— Not recorded.

Etymology:— The specific epithet, pimentae , honors Dr. Ricardo Soares Pimenta, the collector. He also discovered S. pompeoi . He has contributed to our knowledge of palm distributions, palm seed germination, and palm conservation in Brazil.

Distribution and habitat:— The population is restricted to a small area of open cerrado in the southern part of the state of Mato Grosso, Brazil, in the municipality of Rondonópolis. It grows in reddish yellow clay soils.

Conservation:— This is a rare species, threatened by the presence of agricultural development. Corn and soy production surrounds this population. It is also threatened by the expansion of the current roadway. This species is considered critically endangered, CR B1ab(i,ii,iii,v); C2a(i), D.

Phenology:— This palm begins flowering in May. Both flowers and maturing fruits have been seen in August and most have mature fruits by September and October.

Uses:— This is a beautiful palm with potential to become an ornamental landscape palm.

Notes:— This species has foliage that most closely resembles the genus Butia . It has the stiff silvery, bluish-green leaflets that are regularly arranged along a rachis with one side of the leaf forming a V with the other side. However, the inflorescence with its thick, strongly sulcate peduncular bract, the few clustered leaflets at its base, and its lack of a mirrored leaflet Butia anatomy confirm it to be a species of Syagrus .

Specimen examined:— Known only from the type specimen.

Figures

FIGURE 64. Syagrus pimentae. A. Habit. B. Palm with Ricardo Pimenta for scale. C. Palm showing Butia-like leaves with evenly spaced leaflets. D. Old inflorescences. E. Newly opened inflorescence. F. Infructescence. G. Whole plant with infructescence. (Pimenta & Campos-Rocha s.n. [holotype HPL]).

FIGURE 65. Distribution maps of Syagrus pimentae, pleioclada, S. pleiocladoides, S. pompeoi, S. procumbens, S. pseudococos, S. romanzoffiana, S. rupicola, and S. ruschiana.