Macrochloa tenacissima

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 : 94

Macrochloa tenacissima (Loefl. ex L.) Kunth ( Figure 53 (1)).

Lemma dorsal surface (including base): Characterised by rectangular long cells of (40–) 60–100(–140) × (10–) 14– 20(–22) µm, sinuous walls 7–11 µm thick, linear distribution. Short cells: Silica cells 16–21(–26) × 14–20(–24) µm, circular to ovoid, frequent, solitary or in pairs or threes with cork and ioccasionally hook cells, situated between long cells, density (8–)10–14(–15) silica cells/100 µm 2; Cork cells (5–)8–15(–19) × 14–20(–22) µm, sub-quadrangular, reniform to fusiform, sporadic, always with a silica cell. Spines and hairs: Hooks circular to ovoid (frequent) base (17–)20–28(–32) × 8–12(–14) µm high, irregularly distributed between long cells, frequently solitary, sporadically in pairs with silica cells, density <2 hooks/100 µm 2; Prickles circular to ovoid base (20–)24–30(–34) × 19–27(–29) µm, and up to 20 µm long, irregularly distributed between long cells, solitary, density <1 prickle/100 µm 2; Macro-hairs 600–900(–1100) µm long, circular to obovate base 20–26(–28) × 18–20 (–24) µm, irregularly distributed across entire surface, denser at base.

Lemma apical surface: Characterised by long cells similar to those of the dorsal area. Short cells: Silica cells equal in size and morphology, distributed solitarily, in pairs, threes or occasionally a four-cell union with cork cells, hooks and prickles, at lower density (6–)8–10 silica cells/100 µm 2 than in dorsal area; Cork cells of equal size, morphology, distribution and density. Spines and hairs: Hooks of equal size, morphology and frequently with silica cells, denser than in the dorsal area 4–6 hooks/ 100 µm 2; Prickles of similar base morphology and size than in dorsal area, up to 40 µm long, distributed at the middle of the apex, density 2–4 prickles/100 µm 2; Macro-hairs up to 1000 µm long, circular to ovoid base 14–25(–27) × 12–18(–21) µm, distributed at middle of apex. Stomata paracytic, rare in middle of apex.

Material studied: Morocco: Jerada, -203628/ 3433318, 1170 m.s.a.l., 10-IV-2019, M . Chambouleyron ( ECWP s.n. (HSSrf 289(1/2)); Taourirt, 1180 m.a.s.l., 29-IV-2019, M. Chamboleyron, ECWP n.n.

Figures

FIGURE 53. Lemma Surface Macrochloa tenacissima (1) and Macrochloa antiatlantica (2). A. Lemma central dorsal surface view. B. Lemma margin apex surface view. C. Lemma apex. D. Lemma base surface view. lc. Long cell. sc. Silica cell. cc. Cork cell. h. Hook. p. Prickle. mh. Macro-hair. sh. Short hair. s. stomata. Bars indicate 100 µm.