Paspalum ionanthum

Oliveira, Regina Célia De, Valls, José F. M., Gomes, Sueli Maria, Fagg, Christopher W. & Pozzobon, Marisa Toniolo, 2015, A new species of Paspalum, Notata group (Poaceae, Paspaleae), from the Cerrado biome, Brazil: description, chromosome number, and leaf blade anatomy, Phytotaxa 203 (2), pp. 159-168 : 164

Paspalum ionanthum

Material examined: — BRAZIL. Rio Grande do Sul: Capão da Canoa, na Estrada do Mar, ao sul e leste do trevo de acesso a Capão Novo, 8 m, 29º40’53.0”S, 49º59’38.3”W, 18 December 1998, J.F.M. Valls, T.T. Souza-Chies & F. Zilio 14288 (CEN). Quaraí, Beira de várzea à margem oeste do arroio Cati, 112 m, 30º29’42.3”S, 56º12’21.5”W, 03 December 1985, J.F.M. Valls, S. Gonzaga, E. Lemos & S.C. Boechat 9647 (CEN).

External morphological differences between Paspalum cerradoense , P.cromyorhizon ,and P.ionanthum are summarized in Table 1.

Leaf-blade anatomy:— Paspalum cerradoense , P. cromyorhizon , and P. ionanthum have some similar leaf anatomical characters ( Fig. 4A–J ). The leaves of these species are amphistomatic, and can present macro and microhairs or not. The external periclinal walls of the epidermal cells are thinner on the adaxial side, and thicker on the abaxial side. Well-developed bulliform cells are present on the intercoastal region of the adaxial side. Subepidermal fascicles of fibers occur in one or both leaf sides, in the coastal region, and they can be contiguous or not to the vascular bundles. The leaf mesophyll is homogeneous, radiate or not. Vascular bundles are surrounded by a single layer of sheath with chloroplasts, and they can be locked, semilocked, or free. The sheath is complete in the third order bundles of the three species, but it can be complete or incomplete in the first and second order bundles. Parenchyma tissue present in the central adaxial midvein region or not. The leaf margin is deflected or plane, and can be filled or not with a fiber fascicle (sclerenchyma tissue). The leaf anatomical differences between the studied species are presented in Table 2.

Figures

FIGURE 4. A–J. Transverse sections of the leaf blades of Paspalum species. A–C. P. cerradoense R.C. Oliveira & Valls, Oliveira et al. 2693 (holotype). D–F. P. cromyorhizon Trin. ex Döll, Valls et al. 9668. G–J. P. ionanthum Chase, Valls et al. 14288. A, D, G. Parenchyma in the midrib adaxial region (m) present (A) or absent (D, G) in the midvein region. B, E, I. Colorless cells (cc) under bulliform cells (bc) present (B) or absent (E, I). C, F, J. Fiber fascicle (ff) fills the leaf margin (C) or not (F, I). H. Adaxial leaf side, showing a stoma (arrow). Scales: A. 200 μm; D, G. 100 μm; B–C, E–F, H–J. 50 μm.