Bulbostylis litoreamazonicola Maciel-Silva & A. Gil, 2022

Maciel-Silva, Juliene De Fátima, Prata, Ana Paula Do Nascimento, López, Maria Gabriela & Gil, André Dos Santos Bragança, 2022, Bulbostylis litoreamazonicola, a new species of Cyperaceae from the Brazilian Amazonian coast, Phytotaxa 530 (2), pp. 189-197 : 190-194

Bulbostylis litoreamazonicola Maciel-Silva & A. Gil , spec. nov. ( Figs 1–3 )

Type:— BRAZIL. Pará: Maracanã, Ilha de Algodoal , Campo de Moitas , 20-23 March 1995, fl. and fr., L.C.B. Lobato 1032 (holotype: MG150963!, isotypes: IAN165942!, UEC098079!, K001175886!) .

Herb 11–39 cm tall, annual, cespitose, base light brown, not thickened, caudex absent. Leaves 2–9.5 × 0.02–0.03 cm, 1/3 the length of the scape; sheaths 1.7–6 cm long, light brown, sometimes with vinaceous punctuations, chartaceous, membranous toward the apex, at the abscission zone hispidulous, strongly ribbed, apex oblique, sparsely ciliated, hairs 0.5–7 mm long, white, ligule absent; blades setaceous, abaxially with 3 longitudinal ribs, scabrous, margins scabrous, adaxially glabrescent, old leaves with brittle trichomes. Scape 0.2–0.8 mm diam., terete to subterete, longitudinally ribbed, densely hispid to hispidulous, trichomes 0.2–0.5 mm long, sometimes basally thickened. Involucral bracts 3, 1–1.5 × 0.03–0.04 cm, leaf-like, with different lengths, the basal one longest than the others, and not exceeding the inflorescence, surface scabrous, pubescent, proximally winged, margins ciliate with long and sparsely trichomes at the wing apex, with 2–3 mm long. Inflorescence 0.8–2 × 0.7–3 cm, anthelate, simple, lax, spikelets (1–)2–3(–5), the central one sessile, the others on hispidulous branches, 3–15 mm long, erect to curved; prophyllum 1–2 mm long, tubular, on the basal branch, membranous, pubescent, light brown, apex truncate; spikelets 3–12 × 2–3 mm, ovoid, stramineous to light brown, 8–15-flowered; glumes 1.3–2.8 × 1–1.8 mm, deciduous, leaving scars on the axis, ovate to widely ovate, navicular, pubescent, chartaceous, stramineous to light brown, with vinaceous to dark brown maculae, the keel greenish to light brown, salient abaxially, margins hyaline, ciliate, apex short-mucronate, mucro recurved, occasionally erect, glumaceous bracts 2.5–3 × 0.8–1 mm, persistent in spikelet base, lanceolate, stramineous, surface pubescent, margins ciliate, sometimes with long and sparse trichomes, 1–1.5 mm long. Stamens 3, anthers 0.4–0.8 mm long, linear, apex acute; style trifid, 0.8–1.8 mm long, thickened at base, brown to light brown. Nutlet 0.7–1.1 × 0.6–1 mm, trigonous, cordiform, white to yellow when immature, brown to dark brown when mature, base slightly attenuate, frontal angle slightly thickened, surface rugose and transversely wavy, with elongated vertically-oriented cells, silica bodies absent, apex flattened, except for the raised area connecting to the style, stylopodium absent in mature nutlets.

Additional specimens examined (paratypes):— BRAZIL: Pará: Maracanã, Ilha de Algodoal, Praia da caixa d’água, 0°35’2”S, 47°35’13”W, 5 June 2017, fl. and fr., J.F. Maciel-Silva et al. 203 (MG!); Maracanã , Ilha de Algodoal , Praia da Princesa , trecho após a pedra, entre dunas, 0°34’50”S, 47°34’36”W, 5 May 2017, J.F. Maciel-Silva et al. 207 (MG!); Marapanim, just east of the fishing village of Camara which is ca. 11 Km northwest of Marudá , 3 April 1980, fl. and fr., G. Davidse et al. 17813 (INPA!, US!, MO!, NY!) ; Soure, Praia do Turé, 30 May 2018, fl. and fr., E.S.C. Gurgel et al. 1370 (MG!); Marajó. [Ponta do] Maguary , 2 September 1896, fl. and fr., J. Huber s.n. (MG381!); Viseu , Fernandes Belo , restinga da vila Apeu-Salvador , 0°55’31.1”S, 46°11’07.6”W, 24 June 2015, fl. and fr., U. Mehlig & D.P.O. Lima 1658 (HBRA!, MG!) .

Distribution and Habitat:— Bulbostylis litoreamazonicola is known only from the coastal region of the State of Pará, with herbarium records for the municipalities of Marapanim, Maracanã (Algodoal Island), Soure (Marajó Island), and Viseu ( Fig. 4 ). It was found growing over dunes, in seasonally flooded restinga vegetation, and in moist fields near mangroves ( Fig. 5 ).

Conservation Status:— Bulbostylis litoreamazonicola remained overlooked and misidentified for over 120 years in herbarium collections, possibly due to the historical shortage of Cyperaceae specialists for the Amazonian flora. The new species has only seven records, all of them inside Conservation Units (UCs) along part of the Amazonian coast, in the State of Pará: Soure Marine Extractive Reserve (Resex-Mar), Mestre Lucindo Resex-Mar, Gurupi-Piriá Resex-Mar, and Algodoal-Maiandeua Environmental Protection Area (APA). The Pará coastal region presents dunes, mangroves, and restingas. Although this species is found inside areas protected by environmental legislation, they are all sustainable use conservation units, where various human activities are still permitted, with APAs representing the lowest protection priority. This area is subject to serious environmental imbalances, such as predatory tourism, disordered occupation, sand exploitation for civil construction, removal of restinga vegetation, and the grounding of lakes and lagoons ( Santos et al. 1999; Amaral et al. 2008). This species’ currently known distribution results in an extent of occurrence of 5,441 km ² and an area of occupancy of ca. 500 km ². Thus, given the very loose legal constraints ruling these constantly threatened and severely fragmented environments, plus the observed decline in the area of occupancy, extent of occurrence, and quality of habitat, B. litoreamazonicola is assessed as Vulnerable [VU; B1ab (i,ii,iii)+2ab (i,ii,iii)], based on the IUCN (2019) criteria.

Etymology:—The epithet of this species was chosen in reference to the Amazonian coastal region, the area where the species occurs.

Taxonomic relationships: — Bulbostylis litoreamazonicola is mainly characterized by its annual habit, densely hispid to hispidulous leaves, simple anthelate inflorescence, longitudinally ribbed scape, pubescent glumes, cordiform nutlet, and deciduous stylopodium. In Brazil, besides the new species, only four more species of Bulbostylis are characterized by the absence of the stylopodium on the mature nutlets: Bulbostylis communis M.G. López & D. Simpson , B. decidua A. Prata & M.G. López , B. emmerichiae T. Koyama , and B. sellowiana (Kunth) Palla ( Table 1 ). Bulbostylis litoreamazonicola differs from B. emmerichiae and B. sellowiana by its annual habit, base not thickened, inflorescence anthelate, scape terete to subterete, the glumes ovate to widely ovate with short-mucronate apex, and the nutlet cordiform. The other two species share the perennial habit, base thickened, inflorescence capitate, scape trigonous. They differ in their glumes’ shape (lanceolate in B. emmerichiae and ovate in B. sellowiana ), glume apex (acute with tuffs of red trichomes in B. emmerichiae and obtuse in B. sellowiana ), and the nutlet shape (pyriform in B. emmerichiae and obcordiform in B. sellowiana ).

Bulbostylis litoreamazonicola is morphologically similar to B. decidua in its base not thickened, leaf-blades setaceous, ribbed sheaths and scape, inflorescence anthelate, spikelets ovoid, and 3 stamens. It differs from B. decidua by its densely hispid to hispidulous scape (vs. glabrous in B. decidua ), spikelets 3–12 × 2–3 mm (vs. 8–10 × 3–4 mm), glumes 0.7–1.1 × 0.6–1 mm and chartaceous (vs. 1.3–1.5 × 1–1.3 mm and coriaceous), and nutlets cordiform (vs. obovoid). It is also morphologically similar to B. communis due to its annual habit, sheaths with oblique apex, leaflike involucral bracts, and anthelate inflorescence. It differs from B. communis due to its leaf-blades setaceous (vs. filiform in B. communis ), scape terete to subterete and hispid to hispidulous (vs. subtrigonous and glabrous), glumes chartaceous (vs. membranous), 3 stamens (vs. 2), and cordiform and brown to dark brown nutlets (vs. obovoid and white).

Figures

FIGURE 1. Bulbostylis litoreamazonicola. A. Habit. B. Inflorescence with spikelets and involucral bracts, highlighting the scape indumentum. C. Spikelet with glumaceous bracts. D. Lateral view of the glume. E. Frontal and side angle of the nutlet with filament and style presents. F. Frontal and apical view of the mature nutlet lacking a stylopodium. Line drawing by Bobbi Angell, based on G. Davidse et al. 17813 (NY).

FIGURE 2. Bulbostylis litoreamazonicola (J. Huber s.n. - MG381). A. Nutlet in frontal view (digital image). B. Nutlet in frontal view (SEM). C. Detail of the nutlet surface (SEM).

FIGURE 3. Holotype of Bulbostylis litoreamazonicola (L.C.B. Lobato 1032).

FIGURE 4. Distribution map of Bulbostylis litoreamazonicola.

FIGURE 5. Habitats of Bulbostylis litoreamazonicola. A. Princesa beach, Algodoal Island, municipality of Maracanã, State of Pará, Brazil. B. Turé beach, Marajó Island, municipality of Soure, State of Pará, Brazil. Photos by (A) A. Gil; (B) M.N. Carmo.