Syagrus graminifolia subsp. cabraliensis Noblick & Lorenzi, 2014

Noblick, Larry R., Lorenzi, Harri & Souza, Vinicius C., 2014, Four new taxa of acaulescent Syagrus (Arecaceae) from Brazil, Phytotaxa 188 (1), pp. 1-13 : 1-5

Syagrus graminifolia subsp. cabraliensis Noblick & Lorenzi , subsp. nov. (Figs. 1, 2A).

Small usually clustering palm with short and subterranean stems and with a grass-like appearance that differs from the other varieties or forms of Syagrus graminifolia (Drude) Beccari (1916: 466) . by its spike inflorescence (instead of branched to 2–7 rachillae) and its affinity for growing on surface deposits of iron ore called “canga.”

Type: — BRAZIL, Minas Gerais : Joaquin Felicio, ca. 14 km from the city fountain plaza, just outside of the Parque Estadual da Serra Cabral. Elevation ca. 1137 m, 17°41’48.6’’S, 44°13’09.8’’W (-17.696833, -44.219389), 29 January 2014, L. Noblick & H. Lorenzi 5659 (holotype ESA!, isotypes HPL!, BHCB!, RB!, SP!, K!, FTG!, NY!, MO!, US!) .

Small palm, solitary to clustering to 40–50 cm. Stem short and subterranean. Leaves number 3–6 in the crown, sheathing leaf base ca. 8–12 cm long; pseudopetiole (true petiole plus part of the sheath) 9–17 cm long, true petiole 7.5–13 × 0.4–0.5 cm by 0.2–0.3 cm thick, channeled adaxially and rounded abaxially, abaxial side of petiole and rachis tomentose; rachis 26–34 cm long; leaflets narrow and quickly fold longitudinally on drying, slightly lighter on the abaxial surface,

FIGURE. Syagrus graminifolia subsp. cabraliensis . A. whole plant, B. Palms in habitat with author, Noblick, note gravelly “canga” iron-rich soils in foreground, C. Infructescence, D. Inflorescence, E. Closeup of plant with inflorescence. Scale of grid on C and D = 1 cm.

numbering 9–14 along one side, in clusters of 2–3 along rachis and inserted at various angles, ramenta scales or tomentum absent where the leaflets are inserted on the rachis and none along the abaxial midvein; basal leaflets 12–22 × 0.1–0.2 cm, middle leaflets 24–37 × 0.5–0.8 cm, apical leaflets 16–32 × 0.2–0.4 cm with an asymmetric tip. Inflorescence interfoliar, a spike, with prophyll 6–8 × 1.4–1.5 cm, 2-keeled; peduncular bract narrow, woody, sulcate, exterior with scattered thin indumenta becoming thicker at the base of the bract, total length 19–31 cm and with expanded or inflated portion 9.5–16 cm long, 0.8–1.8 cm diameter and a 1.8–2.5 cm perimeter and a 1 mm or less thickness; peduncle glabrous ca. 10–17 × 0.3–0.4 cm; total inflorescence as measured from the first basal flower to the apex 7–9.5 cm long; rachis none; rachilla 1, glabrous, 7–9.5 cm long; staminate flowers green to yellow, arranged in triads on the lower portion or in staminate diads or singly on the upper portion of the rachilla, 5.4–5.9 × 2.2–3.3 mm at apex, 10–10.2 × 2.5–2.6 mm at base, sepals and petals 3 in number, sepals 1–2.4 × 0.5–0.7 mm, glabrous, no visible nerves, keeled and connate at the base, petals valvate, 4.4–5.4 × 1.2–2.2 mm at the apex, 7.0–8.2 × 1.5–2.0 mm at base with acute tips, nerves indistinct, stamens numbering 6, 3.0– 3.7 mm long, anthers 2.4–3.3 mm long, filaments 1.0– 1.7 mm long, pistillode trifid and nearly absent, basal pistillate flowers elongate pyramidal, glabrous, 11.5–11.7 × 4–4.4 mm (apical flowers 10–10.2 × 5–5.5 mm), sepals and petals 3 in number and yellow in color, sepals 8.7–9.5 × 3.6–4.6 mm, glabrous, no visible venation, imbricate, petals 7.7–9.5 × 2.5–3.7 mm, glabrous, obscurely nerved and slightly raised on the lower third of the petal, imbricate at the base but valvate at the tips, the valvate portion a little less than ½ the length of the petals, pistil 7.0–7.2 × 1.8–2.3 mm, glabrous, stigmas 3 in number, and ca. 3.1–3.6 mm long, glabrous, staminodial ring ca. 0.7–1.2 mm and 6-dentate. Fruit brown with yellowish base when mature, tip glabrous, but rest of the fruit with a light to chestnut brown, scaly lepidote tomentum, ellipsoid, 1.9–2.2 × 1.3–1.5 cm, epicarp less than 0.5 mm thick, mesocarp not measured, fleshy-fibrous and endocarp 1.6–1.7 × 1.2–1.3 cm and ca. 1 mm thick, trivittate on the interior of the endocarp, with 3 visible endocarp pores on the basal end and seed elliptical to nearly globose, endosperm homogeneous. Germination remote tubular. Eophyll simple and entire.

Common name:— None recorded.

Etymology:— The name, “cabraliensis”, refers to the isolated Serra do Cabral mountain range where it grows and the state park, Parque Estadual de Serra do Cabral.

Distribution and habitat:— Serra do Cabral is located south of Montes Claros in the central northern part of Minas Gerais and is a mountainous region up to 1,500 m in elevation that is isolated from the rest of the Serra Espinhaço with a unique fauna and flora. The mountain range is located about 70 km SSW of Montes Claros and about 70 km east of Pirapora. The habitat is a high altitude rocky cerrado where the plant grows on surface iron deposits called “canga.”

Conservation:— This palm has only been seen in one locality just outside of the boundaries and protection of the Serra do Cabral state park. The area adjacent to the park is still theoretically an environmentally protected zone. This palm has a strong affinity for growing on the round, gravelly surface iron ore deposits called “canga,” which makes it particularly vulnerable to mining operations. Even after an extended search, no specimens were found growing away from the “canga” iron deposits. About 60% of the current population has been destroyed by surface mining. Therefore, because of the limited and restricted distribution of this taxa and exploitation of the “canga,” by IUCN criteria, this taxon should be classified as EN A2acd; Bab(i,ii,iii), endangered, if not critically so, even though the true extent of its distribution in the region has not yet been determined. Other deposits of “canga” do occur within the adjacent state park.

Phenology:— Flowering and immature fruits in January and February.

Uses:— None recorded. This palm could possibly be used as a landscape plant in those regions with iron-rich soils where other plants might not be able to grow due to the toxicity of the soils.

Additional specimens examined:— Only known from the type specimen.

Notes:— Syagrus graminifolia is a complex of variable specimens from Goiás and western Minas Gerais (Triangular Mineiro). They tend to grow in “campo limpo” cerrado habitats lacking trees and bushes, and in poor, very rocky soils. They can be solitary to clustering, green to silvery-blue, and small to large. The original type specimen was collected in southern Goiás based on William Frank Burchell’s field notes ( Smith & Smith 1967), not Piauí as reported by Glassman (1987). There are at least two different forms in southern Goiás: a larger silvery-bluish one and a smaller green one. A third large, heavily clustering one has been collected from Niquelândia by the second author. All have similar looking slender inflorescences that are branched to one order with 2–7 rachillae. They all have similar leaflet anatomy (Fig. 2).

This new specimen is from north central (not western) Minas Gerais in the Serra do Cabral mountain range that is geographically isolated from the main Serra do Espinhaço. Serra do Cabral is known in Minas Gerais for its unique flora and fauna and much of it has been annexed into a state park. This specimen differs from other S. graminifolia in having only unbranched inflorescences (a spike), growing often in dense clusters, darker green foliage, and an affinity for “canga” iron rich soils. It is different enough to merit its own subspecies status based on its geographical isolation, restricted range and spike inflorescence, but not different enough to deserve new species status, based on its general graminiform aspect and similar leaflet anatomy.

Its similar leaflet anatomy can be seen in the comparable arrangement of the veins and fibers within the crosssections of the subspecies cabraliensis (Fig. 2A), the holotype of S. graminifolia (Fig. 2B) and the variety S. graminifolia var. glazioviana (Dammer) Beccari (1916: 466) (Fig. 2C). The repeating pattern is nearly identical in all three of these (Fig. 2A, 2B and 2C): large vascular bundle or vein, followed by three minor abaxial veins (the middle one being

FIGURE. Leaflet cross-sections. A. Syagrus graminifolia subsp. cabraliensis, Noblick & Lorenzi 5659, B. S. graminifolia , holotype, Burchell 5956 (K), C. S. graminifolia var. glazioviana, R. Tsugi et al. 2682 (HPL), D. S. graminifolia , silver-blue form, note change in pattern, arrows indicate additional smaller minor fibers and opposite faint minor veins between the minor veins. Tsuji et al. 2687 (HPL). Scale = 0.1 mm.

slightly larger) and above each minor vein is a narrow linear strand or fiber bundle. The silvery-blue S. graminifolia (Fig. 2D) endemic to southern Goiás shows a slight change in the pattern with additional smaller minor fibers and opposite faint minor veins between the minor veins. The similar anatomy between all of these suggests a relationship of this new palm from north central Minas Gerais to the others growing in Goiás and the Triangular Mineiro of western Minas Gerais.