Oloptum thomasii (Duby) Banfi & Galasso, 2014

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 : 96-98

Oloptum thomasii (Duby) Banfi & Galasso ( Figure 54 (2)).

Lemma dorsal surface: Characterised by rectangular long cells of (20–)30–80 × 8–10(–12) µm, thin, smooth walls up to 1 µm thick, linear distribution. Short cells: main Silica cells (9–)10–14 µm, circular, frequent, occasionally in pairs with cork cells, situated between long cells, frequently solitary, density 18–20(–22) silica cells/100 µm 2; Cork cells (2–)3–7 × 10–12 µm, reniform, sporadic, always with a silica cell. Spines and hairs: Hooks; Prickles; and Hairs (Macro-hairs) not studied.

Lemma apical surface: Characterised by similar long cells to those of the dorsal area, no significant differences. Short cells: Silica cells of equal size, morphology, distribution and density; Cork cells of equal size, morphology and distribution to those in the dorsal area. Spines and hairs: Hooks, Prickles or Hairs (Macro-hairs) not studied.

Awn base surface: Long cells (8–)12–44(–57) × (6–)7–9(–11) µm, extremes rounded, thin, smooth walls, up to 1 µm thick, linear distribution. No Short cells. Spines and hairs: Prickles of two types: Short Prickles of ovoid to circular base 18–24(–26) × 14–19(–21) µm and up to 55 µm long; Long Prickles to ovoid base 26–45(–57) × 18–28(–32) µm and up to 94 µm long, distributed helicoidally. Stomata paracytic (Parallel wall cells type) between lines of prickles 17–20 µm long, density (4–)7–10(–12) stomata/100 µm 2.

Material studied: Spain: Badajoz, Valle de Santa Ana 16-IX-2015, J . Blanco , C . Vila-Viçosa & F. M . Vázquez HSS65193

Figures

FIGURE 54. Lemma surface Oloptum miliaceum. (1). Oloptum thomasii (2). A. Lemma central dorsal surface view. B. Lemma apex dorsal surface view. C. Lemma apex and awn insertion. D. Awn surface. lc. Long cell. sc. Silica cell. cc. Cork cell. p. Prickle. s. stomata. Bars indicate 100 µm.