Scleria chasmema W. Bonet Mayedo and W. W. Thomas, 2016

Mayedo, Waldo Bonet & Thomas, William Wayt, 2016, Two New Species of Scleria section Hypoporum (Cyperaceae) from Espírito Santo, Brazil, Phytotaxa 268 (4), pp. 263-270 : 264-266

Scleria chasmema W. Bonet Mayedo and W. W. Thomas sp. nov., Figs. 1 , 3 A–B

Scleria chasmema is similar to S. virgata , but has knotted rhizomes, loose, funnel-shaped leaf sheaths, and shorter, broader leaves, among other differences.

Type:— BRAZIL. Espírito Santo: Santa Teresa: Mata Fría [19°55’40”S, 40°42’00”W], Wilon Boon [Wilson Boone] 237, 19 June 1984. (Holotype: MBML image 001542, Isotypes: ICN n.v., MO n.v., NY, RB online image 417175).

Perennial, ca. 1.8 m tall. Roots fibrous. Rhizome 1–1.2 cm diameter, knotted, scaled with reddish cataphylls. Stems erect, 1–1.6 m × 0.7–1 cm, becoming narrower distally, trigonous, the angles retrorsely scabrous, the faces scabrous, longitudinally striated, the distal portion of each node pubescent, the hairs pale castaneous to whitish. Leaves basal and cauline, ca. 15 per culm, the basal 2–3 bladeless, the rest with well-developed blades and sheaths; sheaths 6–8 cm long, funnel-shaped, 1.5–2 cm wide distally, scaberulous along the angles, pubescent on the faces, green to pale castaneous; ligule absent; contraligule prominent, rounded, 5–7 × 10–15 mm, pubescent, the margins ciliate, not auriculate; blades linear-lanceolate, 13–25 × 2–4.2 cm, increasing in size distally, glabrate above and beneath but puberulent along major nerves, the margin scaberulous and ciliate, the hairs whitish to pale castaneous, the apex long-acuminate, not pseudopremorphous (not contracting abruptly). Inflorescence terminal, paniculate, 21–35 cm long, comprising 10–11 synflorescences with lax, well-spaced branches disposed spirally along the principal axis; neither branches nor spikelets subtended by obvious bracts; terminal synflorescences sessile or subsessile, contracted; proximal synflorescences with branching reaching the third, rarely the forth order; axis supporting each group of spikelets filiform and lax; prophyll at the base of the inflorescence tubular, 2–4 mm long, reddish. Spikelets all androgynous, 3–4 × 1–1.2 mm, ovoid, laterally compressed, sessile, spirally disposed, well-spaced, single or rarely two together, erect, pale castaneous or reddish; the primary axis angled, scaberulous and pubescent, the hairs transparent; spikelet scales 2–2.2 × 1–1.5 mm, broadly lanceolate, the four basal scales sterile and distichous, glabrous, chartaceous, pale castaneous with elongate reddish spots along the margins, the central nerve prominent and terminating in an apiculus; more distal glumes fertile, decreasing in size distally, helicoidally or spirally arranged, hyaline, glabrous, not apiculate, the abaxial face pale castaneous, the central nerve reddish. Pistillate flower single, subtended by the 5 th spikelet scale, the single style filiform, flexuous, divided halfway into 3 stigmas. Staminate flowers several, subtended by the 6 th and more distal scales, comprising two stamens. Fruit comprising a cupule subtending an achene; cupule flat, trigonous, 0.5 mm high, reddish, not dispersing with the achene; hypogynium absent; achene subglobose-trigonous, 3–3.2 × 1.8–2 mm, apiculate, gray to whitish, the base trigonous, the surface tuberculate-rugose, glabrous, the style base normally not persistent.

Distribution and Ecology:—Both known collections are from an area called Mata Fría, at 700–800 m, 19°55’40”S, 40°42’00”W, in the municipality of Santa Teresa, Espírito Santo, Brazil ( Fig. 4 ). The collections were made in partially shaded forest in dark soil, in an area that is naturally tropical submontane or montane moist forest.

Preliminary Conservation Status:—The species is known from only two collections, both from Mata Fría, a forest fragment of the critically endangered Atlantic montane forest ( Ribeiro et al. 2009). Since it occurs in an area that is relatively well collected, near the town of Santa Teresa, the lack of collections from other localities suggests that it has a very limited distribution. Its limited occurrence in an endangered habitat suggests that it deserves consideration as an Endangered species.

Etymology:—The specific epithet refers to the loose, open leaf sheath characteristic of this species.

Additional Specimen Examined (Paratype):— BRAZIL. Espírito Santo: Santa Teresa: Mata Fría [19°55’40”S, 40°42’00”W], entrada para Tabócas, 18 Sept 1985, H. Q. Boudet Fernandes 1513 (MBML-001448 image, MO online image 3717835, NY).

Notes: — Scleria virgata differs from S. chasmema by having a slender elongate rhizome, constricted, glabrous leaf sheaths, a large, pubescent contraligule, inflorescence branches to 80 cm long, fascicles with 1–15 spikelets, and an achene surface with transversely elongate warts ( Table 1). Notes on the holotype indicate that duplicates were distributed to both ICN and MO, but those isotypes could not be found.

from personal observation; data for S. variegata taken from personal observation and Core (1936).

Figures

FIGURE 1. Illustration of Scleria chasmema. A. Base of plant. B. Leaf sheath and blade. C. Inflorescence. D. Detail of inflorescence. E. Spikelet. F. Opened spikelet showing scales and pistillate flower. G. Staminate flower and subtending scale. H. Terminal spikelet with fruit. I. Achene. A, I from Boon [Boone] 237 (NY); B–H from Fernandes 1513 (NY). Illustration by Bobbi Angell.

FIGURE 3. A–B. SEM photos of Scleria chasmema achene. A Whole achene. B Achene surface. (A–B, A.P. Fontana et al. 4911). C–D. SEM photos of Scleria didina achene. C Whole achene. D Achene surface. (C–D, W. Boon [Boone] 237).

FIGURE 4. Distribution of Scleria chasmema (blue dot) and S. didina (red dots) in the state of Espírito Santo, Brazil.