Stipa atlantica P. Smirn., 1929

Vázquez, Francisco Maria, Márquez, Francisco, García, David & Oualidi, Jalal El, 2025, A taxonomic revision of Stipeae s. l. tribe (Poaceae) in N Africa, Phytotaxa 699 (1), pp. 1-174 : 100-101

Stipa atlantica P. Smirn. ( Figure 57 (1)).

Lemma dorsal surface: Characterised by long rectangular cells of (15–)25–53(–61) × (7–)11–17(–20) µm, sinuous walls up to 5 µm thick, linear distribution. Short cells: Silica cells of 6–12 × 5–10 µm, circular, obovate to oblong, frequently in pairs or threes with hook cells, less often with cork cells, situated between long cells, never solitary; Cork cells (2–)3–9(–10) × 7–10 µm, sub-reniform to fusiform, sporadic, always with a silica cell. Spines and hairs: Hooks sub-quadrangular to circular base (7–)10–18(20) × 4–8(–10) µm high, regularly distributed between long cells, in pairs or threes with silica, cork cells, more frequently solitary, density 9–12 hooks/100 µm 2; Macro-hairs> 600 µm long, with circular base 11–20 µm, regularly distributed in lines from mid-dorsal to base of lemma.

Lemma apical surface: Characterised by long cells similar to those of the dorsal area, slightly longer to 80 µm and up to 6 µm thick, sinuous walls. Short cells: Silica cells of 5–12 × 7–14 µm, more frequent than in dorsal area and similar distribution and morphology to the dorsal; Cork cells (2–)3–8 × 7–9 µm, oblong to sub-reniform, of equal distribution to the dorsal. Spines and hairs: Hooks circular base 9–17 µm, less dense than in dorsal area 7–10 hooks/100 µm 2; Prickles absent; Macro-hairs of obovate to circular base, located at margin leading up to apex.

Awn base surface: Characterised by long cells of acute to oblique apices to 380 µm on twisted, flat and angled parts. Short cells absent. Spines and hairs: Hooks absent; Prickles absent; flat area smooth; Macro-hairs not observed. Stomata paracytic (Parallel-sided subsidiary cells type), of linear distribution on flat parts and grooves between twists, density 120–160(–200) stomata/ 1 cm 2.

Material studied: Morocco: Timahdik, 2350 m.a.s.l., 24-VI-2020, M . Chamboleyron , ECWP n.n.

Figures

FIGURE 57. Lemma surface Stipa atlantica. (1). Stipa mediterranea (2). A. Lemma central dorsal surface view. B. Lemma margin dorsal surface view. C. Lemma apex. D. Awn surface. lc. Long cell. sc. Silica cell. cc. Cork cell. h. Hook. p. Prickle. mh. Macro-hair. s. stomata. Bars indicate 100 µm.