Syagrus guimaraesensis Noblick & Lorenzi (2014: 10)

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

25. Syagrus guimaraesensis Noblick & Lorenzi (2014: 10) . Type: — BRAZIL. Mato Grosso: Chapada dos Guimarães, Parque Nacional da Chapada dos Guimarães , near Véu da Noiva (Bridal Veil) waterfalls, elevation ca. 611 m, –15.41, –55.83, 12 January 2014, L.R. Noblick & H. Lorenzi 5640. (holotype ESA!, isotypes HPL!, UFMT!, RB!, SP!, K!, FTG!, NY!, MO!, US!)

Figure 36 plate, Figure 29 map.

Small, solitary palm to ca. 80 cm. Stem short, subterranean; rhizome 4.5–10 × 3.5–5.5 cm. Leaves 2–4(–5); sheathing leaf base ca. 4.5–18 cm long; pseudopetiole 2.5–11 cm long; petiole 0.5–6 × 0.4–0.7 cm, 0.2–0.4 cm thick; rachis 11–56 cm long; leaflets slightly lighter on the abaxial surface, 6–16 along one side, distributed mostly regularly but in clusters of 2 or 3 near the base, ramenta scales or tomentum absent where the leaflets are inserted on the rachis, and none along the abaxial midvein; basal leaflets 27–48 × 0.1–0.5 cm, middle leaflets 36–75 × 0.4– 0.7 cm, apical leaflets 24–38 × 0.1–0.5 cm with an asymmetric tip. Inflorescence spicate, prophyll 6.5–8.5 × 1–2 cm; peduncular bract 7.5–23 cm including a 0–1.5 cm beak, expanded portion 4.5–11 × 2–3 cm, beak not measured, 3–6 cm perimeter, 1–3 mm thickness, narrow, woody, sulcate, exterior with scattered thin indument; peduncle ca. 2.5–11 cm × 2–6 mm, glabrous or with a few scattered scales; inflorescence axis 3–7.5 cm long; rachis absent; rachilla 1, glabrous, 3–7.5 cm long; staminate flowers 10–11 × 3.8 mm at the apex, 12.5–12.8 × 3.5– 4.0 mm at the base, green to yellow, sepals 2.3–3.4 × 1.0– 1.7 mm, glabrous, no visible nerves, petals 8.7–11 × 2.9– 3.7 mm at the base with acute tips, nerves indistinct, stamens 3.4–4.4 mm long, anthers 2.2–2.7 mm long, filaments 1.7–2 mm long, pistillode nearly absent; pistillate flowers elongate pyramidal, 11.5–11.7 × 6.2–6.6 mm at the apex, 13.2–16.8 × 6.9–7.9 mm at the base, yellow, glabrous, sepals 9.5–16.8 × 3.2–7.7 mm, glabrous, no visible venation, petals 6.7–15.3 × 2.8–5.5 mm, glabrous, obscurely nerved on the lower portion of the petal, valvate tips ½ or more the length of the petals, ca. 3.5–8 mm long, pistil 6.1–8.0 × 2.5–3.7 mm, glabrous, stigmas less than 3 mm long, glabrous, staminodal ring ca. 0.5–0.9 mm high, truncate to undulate. Fruit ellipsoid, 2.0 × 1.6 cm, reddish-brown when mature, covered with small stiff appressed brownish hairs, broadly epicarp less than 0.5 mm thick, mesocarp not measured, succulent and fibrous; endocarp not measured; seed ellipsoid not measured, endosperm homogeneous. Germination remote-tubular.

Common name:— None recorded.

Etymology:— The specific epithet, guimaraesensis , refers to the Parque Nacional de Chapada dos Guimarães , where it was discovered and the type collected.

Distribution and habitat:— South central Mato Grosso, Brazil. This species grows in very rocky sandy soils both within and outside of the National Park of the Chapada dos Guimarães , near the town of Chapada dos Guimarães. It grows in decomposed sandstone soils, with specimens seen as far south as Rondonópolis and as far north as Diamantino. Also reported to be growing as far as 350 km to the west and at elevations usually above 600 m, but never in large numbers (Lorenzi, pers. comm.).

Conservation:— This species is well protected within the national park, and it usually grows in very rocky soils that are of no agricultural importance, except for pasture. Therefore, this palm is classified as least concern, LC.

Phenology:— Fruiting and flowering in January in exposed areas, but neither flowering nor fruiting in shadier areas at this time of year.

Uses:— None recorded. This palm has landscaping potential.

A REVISION OF THE GENUS SYAGRUS

Phytotaxa 294 (1) © 2017 Magnolia Press • 103 104 • Phytotaxa 294 (1) © 2017 Magnolia Press

NOBLICK

Notes:— This species resembles the Bolivian S. petraea , which was formerly the name erroneously given to most acaulescent Syagrus in Brazil with spicate inflorescences. It even grows in a similar environment of decomposed sandstone weathered into “chapada” topography. However, morphologically Syagrus guimaraesensis differs in having a shorter leaf rachis (11–56 vs. 40–125 cm), fewer leaflets (6–16 vs.19–42), and thicker leaf blades. Their leaflet anatomy differs by the following characters: S. guimaraesensis has large major veins (vs. small major veins in S. petraea ), presence of adaxial minor veins near the leaflet margin (vs. no adaxial minor veins near the leaflet margin) and small fiber bundles between the major veins along the adaxial surface (vs. large fiber bundles between the veins).

Representative specimens:— BRAZIL. Mato Grosso: Chapada dos Guimarães, Mirante do Centro Geodésico, 19 October 1995, G. Hatschbach et al. 63584 (FTG!); Chapada dos Guimarães , na estrada para Cuiabá, km 49, próximo ao Parque Nacional da Chapada dos Guimarães em cerrado mais ou menos denso, sobre solo arenoso com muitos pedras, comum em toda a região numa extensão de mais de 350 km para o leste em elevation sempre superior a 600 m, porém sem nunca formar grandes infestações, 680 m, –15.39, –55.83, 9 December 2009, H. Lorenzi , et al. 6786 (HPL!); PARNA Chapada dos Guimarães , 19 November 1999, L.A. Neto et al. 989 (UFMT!); Chapada dos Guimarães, Parque Nacional da Chapada dos Guimarães , near the Monumento da Pedra in the National Park near km 49, Elevation ca. 601 m, –15.39, –55.83, 12 January 2014, L.R. Noblick & H. Lorenzi 5639 (ESA!, HPL!, FTG!, NY!); Cuiabá, Rio Caxipozinho, próx. a Cachoeira Véu de Noiva, Área da Chapada dos Guimarães , 21 October 1985, C.A. Cid Ferreira 6530 (SPF, NY); Diamantino, cerca de 20 km após o limite do município de Diamantino. Área de grandes afloramentos rochosos, 23 April 1983, E.C.C. Moraes et al. 278 (UFMT!).

Figures

FIGURE 29. Distribution maps of Syagrus flexuosa, S. glaucescens, S. glazioviana, S. gouveiana, S. graminifolia subsp. cabraliensis, S. graminifolia subsp. glazioviana, S. graminifolia subsp. graminifolia and S. guimaraesensis.

FIGURE 36. Syagrus guimaraesensis. A. Habit. B. Infructescence with side view of fruit. C. Inflorescence and older peduncular bract. D. Infructescence with apical view of fruit. White scale = ca. 1 cm.