Parianella capixaba F.M.Ferreira & R.P.Oliveira, 2022

Ferreira, Fabricio Moreira, Oliveira, Reyjane P., Clark, Lynn G. & Welker, Cassiano A. Dorneles, 2022, A new species of Parianella (Poaceae, Bambusoideae, Olyreae) marks the southernmost distribution of the genus in Brazil, Plant Ecology and Evolution 155 (3), pp. 425-432 : 425

Parianella capixaba F.M.Ferreira & R.P.Oliveira sp. nov.

Figs 1 , 2

Type.

BRAZIL • Espírito Santo, Santa Leopoldina, Serra do Ramalhete, Caioaba Farm ; 15 Feb. 2006; V. Demuner, L.F.S. Magnago, M. Belisário & E. Bausen 1828; holotype: MBML [MBML00019821] .

Diagnosis.

Parianella capixaba is similar to the other two congeneric species in its culm length and gynecandrous whorl length and width, but can be differentiated by its well-developed rhizomes, longer and wider leaf blades, longer synflorescences, and longer staminate spikelets with longer pedicels and glumes.

Description.

Plants perennial, caespitose, with well-developed rhizomes. Culms monomorphic, erect, 50-90 cm long, 3-5.5 mm diam. near the base; internodes striate, glabrous; nodes thickened, glabrous; leaves 5-6 per culm; leaf sheaths slightly keeled, not inflated, glabrous to slightly pilose, margins ciliate, fimbriae at the apex present, persistent, 29-72 per leaf sheath, spreading, straight at the base, curly towards the top, 10-35 mm long; ligules entire, 1.5-2 mm long; pseudopetioles 1-2 × 1-2 mm, stramineous, glabrous on both sides; leaf blades 40-47 × 4-5 cm, lanceolate, base attenuate, symmetric, apex acuminate, concolor, glabrous on both sides, margins scabrous. Synflorescences ca 15 cm long, terminal, solitary, with only gynecandrous whorls; gynecandrous whorls 10-15 × 4-6 mm, ca 7 per synflorescence; pistillate spikelet 1 per whorl; staminate spikelets 5 per whorl. Pistillate spikelets 9-10 × 3-4 mm, oblong, stramineous; glumes 9-10 × 3-4 mm, membranous, hyaline, lanceolate to oblong, acuminate to shortly caudate, glabrous to slightly pilose, 1-nerved; lemma 8-9 × 3-4 mm, cartilaginous, oblong, apex acuminate, glabrous at the base and shortly scabrous at the apex, 8-nerved; palea 8-9 × 2.5-3 mm, cartilaginous, lanceolate, apex acuminate, glabrous at the base and slightly scabrous at the apex, 2-4-nerved. Caryopsis not seen. Staminate spikelets 4-5 × 1.5-2 mm, oblong; pedicels 9-13 mm long, laterally connate in two pairs plus one free pedicel (2 + 2 + 1 pattern), pilose at the base; glumes 3.5-4 × 0.7-1.3 mm, papyraceous, triangular, apex acute, pilose to slightly scabrous, 1-nerved; lemma 4-5 × 1.5-2 mm, papyraceous, oblong to ovate, apex obtuse to acute, glabrous at the base and slightly villous at margins and apex, 3-nerved; palea 3.5-4.5 × 1-1.5 mm, papyraceous, oblong to ovate, apex obtuse to rounded, glabrous or pilose to villous towards the apex, 2-nerved; anthers not seen. Spikelet of the terminal whorl not seen.

Distribution.

This new species is known from only two localities in the Brazilian state of Espírito Santo, both of them in its southern portion: one in the Serra do Ramalhete (municipality of Santa Leopoldina, ranging from 200 to 500 m in elevation), and the other in the Duas Bocas Biological Reserve (municipality of Cariacica, at ca 525 m elevation) (Fig. 2 ).

Habitat and ecology.

Both localities lie in the Krenák-Waitaká Forests (KWF) ( Saiter et al. 2016; Alves-Araújo et al. 2022), one of the three subregions in the central centre of endemism of the Atlantic Forest ( Thomas et al. 1998; Murray-Smith et al. 2009). The vegetation of this region is characterized as a semi-deciduous seasonal submontane forest, due to climatic conditions, altitudinal ranges, and soil types ( Assis et al. 2007). Parianella capixaba represents the southernmost distribution of the genus known so far since the other two species ( P. carvalhoi and P. lanceolata ) are endemic to Bahia state.

Etymology.

The specific epithet “capixaba” is a noun in apposition and the local name for Espírito Santo inhabitants. The epithet also alludes to the first record of the genus Parianella outside Bahia state.

IUCN conservation assessment.

Endangered: EN B2ab(ii,iii,iv). According to the IUCN Standards and Petitions Committee (2022), Parianella capixaba would be considered Endangered (EN), based on criteria B2ab(ii,iii,iv), with an AOO of 8 km2. Although the species occurs in a Conservation Unit (Duas Bocas Biological Reserve, Espírito Santo, Brazil), we suggest this category based on its very restricted distribution. Furthermore, the Atlantic Forest is one of the most endangered biodiversity hotspots ( Ribeiro et al. 2009; Rezende et al. 2018), especially in Espírito Santo state, where urbanization and industrial and agricultural expansion have led to a great loss and fragmentation of the vegetation ( Pereira 2007; Alves-Araújo et al. 2022).

Additional material examined (paratypes).

BRAZIL - Espírito Santo • Cariacica, Duas Bocas Biological Reserve; 22 Jul. 2008; C.N. Fraga, A.M.A. Amorim, R.C. Forzza, P.H. Labiack, R. Goldenberg, J.L. Paixão & L.C.J. Gomes 2183; RB [RB00549297]; CEPEC n. 130402; HUEFS [HUEFS000013599]; MBML [MBML00019822, MBML00019823]; UPCB [UPCB0038332].

Notes.

Parianella capixaba overlaps morphologically with both P. carvalhoi and P. lanceolata in some characters (Table 1 ). However, the new species can be differentiated by its longer and wider leaf blades (40-47 × 4-5 cm vs (6-)11.5-20 × 2.1-3.4 cm in P. carvalhoi and (7.5-)11-16(-21.4) × 0.7-1.7(-2.5) cm in P. lanceolata ), longer synflorescences (ca 15 cm long vs 6.5-8 cm in P. carvalhoi and 5-8 cm in P. lanceolata ), and longer staminate spikelets (4-5 mm long vs 2-2.5 mm in P. carvalhoi and 2.5-3.2 mm in P. lanceolata ) with longer pedicels (9-13 mm long vs 7-8.2 mm in P. carvalhoi and 7.2-8 mm in P. lanceolata ) and longer glumes (3.5-4 mm long vs 2-3 mm in P. carvalhoi and 2.2-3 mm in P. lanceolata ) (Table 1 ). A remarkable characteristic of the new species is its well-developed rhizomes, in contrast with both P. carvalhoi and P. lanceolata , which have poorly developed rhizomes ( Judziewicz et al. 1999; Oliveira et al. 2004). The absence of well-developed rhizomes in the latter two species (treated as Pariana at that time) was considered by Soderstrom and Calderón (1974) as “primitive” (plesiomorphic) in comparison to Pariana from Amazon and Central America. However, according to Ferreira et al. (2019), the loss of a rhizome system in Parianella could be regarded as derived, which could be investigated with the well-developed rhizome observed in P. capixaba . More studies, including molecular phylogenetic analyses, are necessary to test this hypothesis.

Figures

Figure 1. Parianella capixaba sp. nov. A. Culm. B. Rhizome. C. Detail of the leaf sheath apex showing pseudopetiole and fimbriae. D. Synflorescence. E. Gynecandrous whorl showing staminate spikelets with glumes (g) and long pedicels (p). F. Lemma of the pistillate spikelet. G - H. Glumes of the pistillate spikelet (abaxial view). Drawn by Fabricio Moreira Ferreira; A-B: from the paratype (C. N. Fraga et al. 2183, HUEFS 000013599); C-H: from the holotype (V. Demuner et al. 1828, MBML 00019821).

Figure 2. Geographical distribution of species of Parianella. Brazilian state abbreviations: BA - Bahia; ES - Espirito Santo; MG - Minas Gerais.