Macrochloa Kunth (1829: 58)

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 : 28-34

Macrochloa Kunth (1829: 58) .

Type:— Macrochloa tenacissima (Loef. ex L.) Kunth (1829: 58).

≡ Lasiagrostis sect. Macrochloa (Kunth) Trinius & Ruprecht (1842: 94) .

≡ Stipa L. sect. Macrochloa (Kunth) Pfeiffer (1872: 132) .

≡ Stipa L. sect. Macrochloa (Kunth) F.M. Vázquez & Devesa (1996: 161) , comb. superfl.

≡ Stipa L. subgen. Macrochloa (Kunth) Barreña, D. Rivera, Alcaraz & Obón (2006: 7) .

Perennials, caespitose, simple panicle highly ramified, short peduncle. Flower glumes sub-equal, lemma apex dents; palea entire or denticulate, homogeneous pubescence, involved margins; anthers apex hairs; callus acute; awn bigeniculate, plumose, long.

Key to the Macrochloa species

1.

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2.

- Sheaths pubescent .................................................................................................................................................... M. antiatlantica . Sheaths smooth ................................................................................................................................................................................ 2. Palea glabrous with entire apex ................................................................................................................................ M. tenacissima . Palea pubescent, with dentate apex ............................................................................................................................ M. gabesensis .

1. Macrochloa antiatlantica (Barreña, D. Rivera, Alcaraz & Obón) H. Scholz & Valdés (2006: 663) . ( Figure 10 & 11 (b4–h4))

Type:— MOROCCO. Agadir. Tizi Mlil, near Tafraoute (Anti Atlas) 29°43’N, 8°51’W, unploughed grounds on volcanic substrata, 1800 m.a.s.l.,, 5 June 1980, A. Charpin, J. Fernández-Casas, F. Jacquemoud & D. Jeanmonod MAR-275 (holotype G179625 ! ( G22751 )!, isotype MA-292529!, designated by Barreña, Rivera, Alcaraz & Obón (2006: 13)) .

≡ Stipa antiatlantica Barreña, D. Rivera, Alcaraz & Obón (2006: 13) . (Bas.)

≡ Stipa tenacissima var. villosiuscula Lindberg (1932: 24) (Lectotype H1068682! (digital imagen), Lectoparatype H1068681! (digital imagen) designate here).

= Stipa tenacissima subsp. atlantica J. Barreña , in herb. (G360087!).

Culm erect not geniculate at the base, pubescent in the vegetative leaves (sheaths), 80–160 cm tall; prophylls aristate, 8–10 cm plumose arista, to tomentose. Leaves with sheaths pubescent to lanuginose upper on the stem, free margin, scabrid; ligule to 2 mm, transform in the line of hairs; vegetative blades culms to 61 cm long, convolute, abaxially glabrous to pubescent in sheath contact, adaxially scabrous to villous striated, scabrous on the margin, to 2.1 mm of diameter; fertile blades culms to 29 cm long, convolute, abaxially smooth, adaxially scabrous to villous, striated, scabrous on the margin, to 2.2 mm of diameter, rigidly sharp-pointed acute. Inflorescence to 33 cm long, panicle lanceolate, falling, loose, the axis glabrous to scabrid, alternate to sub-verticillate branches, slender, sub-flexuous, smooth to scabrid, spikelet-bearing in all inflorescence. Spikelet free, progressive in flowering, the lateral pedicel of last flower up to 15 mm long, frequently scabrid; glumes narrow, sub-equal, 20–27(–29) mm long, green to purple when immature to purple when mature with hyaline long-acuminate tips, 3 ribs smooth to finely scabrid; lemma slender, fusiform, 7–9(–9.2) mm long, homogenously pubescent apex truncate, ciliate and aristate, with arista to 2 mm long; callus sharp and slender, 1.7–2.8 mm long, villous with adpressed white hairs; palea lanceolate 7.5–9.5(–10) mm, dorsally pubescent, apex denticulated; awn 5.5–7.5(–8) cm long, persistent, bigeniculate, the first segment (column) ca. 1.8 cm long, twisted, scabrid-villous with ascending hairs to 4.3 mm long, one geniculate, the second segment (rest or seta) to 6 cm, flexuous, angled, scabrous, gradually less scabrid up to tip; lodicules 3, unequal, the two laterals 1.5–2 mm long, acute, lanceolate, 1–2 ribs, apex entire, the posterior lineal longer than laterals, to 0.2 mm long; anthers 7.5–8.5(–9) mm long, apex apiculate, bearded with hairs to 0.3 mm; stigma 2–3, plumose. Caryopsis not studied ( Figure 11 (b4–h4)).

Phenology:—Flowering June to July.

Habitat:—Open areas in SW Morocco, up to 2000 m a.s.l., on calcareous soils and in volcanic areas.

Distribution:—[Stenomediterranean-Maroccan]. Endemic to the Anti- and High-Atlas ( Morocco) ( Figure 10 ).

2. Macrochloa gabesensis (Moraldo, Raffaelli & Ricceri) F.M. Vázquez comb. nov. ( Figure 11 (b2,3–h2,3) & 12).

Type:— TUNISIA. Pseudosteppe aux environs de Gabès, 16 April 1986, Raffaelli & C. Ricceri s.n. [holotype FI001105 ! [digital image], designated by Moraldo, Raffaelli & Ricceri (1989: 78)).

≡ Stipa gabesensis Moraldo, Raffaelli & Ricceri (1989: 78) (Bas.).

≡ Stipa tenacissima subsp. gabesensis (Moraldo, Raffaelli & Ricceri) Barreña, D. Rivera, Alcaraz & Obón (2006: 13) .

≡ Macrochloa tenacissima subsp. gabesensis (Moraldo, Raffaelli & Ricceri) H. Scholz & Valdés (2006: 663) .

Culm erect not geniculate at base, glabrous to scabrid, 60–180 cm tall; prophylls aristate, 8–11 cm plumose arista, pubescent to tomentose. Leaves with sheaths glabrous on the stem, free margin, scabrid; ligule to 2 mm, transform in line of hairs; vegetative blades culms to 75 cm long, convolute, abaxially glabrous, adaxially scabrous to villous striated, scabrous on the margin, to 2.2 mm of diameter; fertile blades culms to 34 cm long, convolute, abaxially smooth, occasionally scabrous, adaxially scabrous to villous, striated, scabrous on the margin, to 2.5 mm of diameter, rigidly sharp-pointed acute. Inflorescence to 37 cm long, panicle lanceolate, falling, loose, the axis glabrous to scabrid, alternate to sub-verticillate branches, slender, sub-flexuous, smooth to scabrid, spikelet-bearing in all inflorescence. Spikelet free, progressive in flowering, the lateral pedicel of last flower to 16 mm long, frequently scabrid; glumes narrow, sub-equal, 19–30(–38) mm long, green to purple when immature to purple when mature with hyaline long-acuminate tips, 3 ribs smooth to finely scabrid; lemma slender, fusiform, 5.5–9(–9.5) mm long, homogeny pubescent apex truncate, ciliate and aristate, with arista to 2.2 mm long; callus sharp and slender, 1.5–3 mm long, villous with adpressed white hairs; palea lanceolate 6.5–10(–11) mm, dorsally pubescent, bifid; awn 4.5–9.5(10.5) cm long, persistent, twice-geniculate, the first segment (column) ca. 2 cm long, twisted, scabrid-villous with ascending hairs to 4.5 mm long, unigeniculate, the second segment (rest or seta) to 7 cm, flexuous, angled, scabrous, gradually less scabrid up to tip; lodicules 3, unequal, the two laterals 1.5–2 mm long, acute, lanceolate, 1–2 ribs, apex entire, the posterior lineal longer than laterals, to 0.25 mm long; anthers 6.5–10(–11) mm long, apex apiculate, bearded with hairs to 0.3 mm long; stigma 2–3, plumose. Caryopsis terete, fusiform, 5–8(–8.5) mm long, brown to pale brown ( Figure 11 (b2,3–h2,3).

Distribution:—[Stenomediterranean-North Africa]: Algeria, Morocco, Tunisia ( Figure 12 ). Expected in Libya.

Representative specimens:—Appendix II.

Key to the Macrochloa gabesensis subspecies

1. Glumes (19–25(–29) mm long. Awn 4.5–8.5 cm .......................................................................... M. gabesensis subsp. gabesensis . - Glumes (30–) 32–38 mm. Awn 7–9.5(–10.5) cm ............................................................................... M. gabesensis subsp. kelibiae .

2a. Macrochloa gabesensis subsp. gabesensis (Moraldo, Raffaelli & Ricceri) F.M. Vázquez ( Figure 11 (b2–h2) & 12).

= Stipa kralifii Moraldo, Raffaelli & Ricceri (1989: 80) [holotype FI001106! [digital image], designated by Moraldo, Raffaelli & Ricceri (1989: 80)].

Culm 60–150 cm tall, erect not geniculate at base, glabrous to scabrid; prophylls aristate, to 11 cm. Leaves with sheaths glabrous; ligule to 2 mm, transform in line of hairs; vegetative blades culms to 66 cm long, convolute, abaxially glabrous, adaxially scabrous to villous striated, scabrous on the margin, to 2.2 mm of diameter; fertile blades culms to 27 cm long, convolute, abaxially smooth, occasionally scabrous, adaxially scabrous to villous, striated, scabrous on the margin, to 1.8 mm of diameter, rigidly sharp-pointed acute. Spikelet free, progressive in flowering, the lateral pedicel of last flower to 16 mm long, frequently scabrid; glumes narrow, sub-equal, 19–25(–29) mm long, green to purple when immature to purple when mature with hyaline long-acuminate tips, 3 ribs smooth to finely scabrid; lemma slender, fusiform, 5.5–9 mm long, homogeny pubescent apex truncate, ciliate and aristate, with arista to 2.2 mm long; callus sharp and slender, 1.5–3 mm long, villous with adpressed white hairs; palea lanceolate 6.5–10 mm, dorsally pubescent, bifid; Awn 4.5–8.5 cm long, persistent, bigeniculate, the first segment (column) ca. 2 cm long, twisted, scabrid-villous with ascending hairs up to 4.5 mm long, unigeniculate, the second segment (rest or seta) to 6 cm, flexuous, angled, scabrous, gradually less scabrid up to tip; anthers 6.5–10 mm long. Caryopsis terete, fusiform, 5–8 mm long, brown to pale brown ( Figure 11 (b2–h2)).

Phenology:—Flowering March to June.

Habitat:—Open areas with calcareous soils, below 2200 m a.s.l., forming espartals in arid areas with less than 500 mm of rainfall per year.

Distribution:—[Endemic Stenomediterranean-North Africa]: Algeria, Morocco, Tunisia ( Figure 12 ). Expected in Libya.

Notes:—Within this subspecies, qualitative and quantitative variation has been detected. Compared with typical specimens, some have small-sized floral pieces (palea ≤ 8.5 mm, vs.> 8 mm, and lemma ≤ 6.8 mm, vs> 6.5 mm). These variations were not considered taxonomically because they occured within the range of species variation.

2b. Macrochloa gabesensis subsp. kelibiae (Moraldo, Raffaelli & Ricceri) F.M. Vázquez comb. et stat. nov. ( Figure 11 (b3–h3) & 12).

Type:— TUNISIA. Betw. Kelibia & El-Haouaria, 30 m, 13 April 1986, M. Raffaelli & C. Ricceri s.n. [holotype FI001104 ! [digital image], designated by Moraldo, Raffaelli & Ricceri (1989: 80)).

≡ Stipa kelibiae Moraldo, Raffaelli & Ricceri (1989: 80) (Bas.).

Culm 90–180 cm tall, erect not geniculate at base, glabrous to scabrid; prophylls aristated, to 8.5 cm plumose arista, pubescent to tomentose. Leaves with sheaths glabrous on the stem, free margin, scabrid; ligule to 2 mm, transform in line of hairs; vegetative blades culms to 75 cm long, convolute, abaxially glabrous, adaxially scabrous to villous striated, scabrous on the margin, to 2.5 mm of diameter; fertile blades culms to 34 cm long, convolute, abaxially smooth, occasionally scabrous, adaxially scabrous to villous, striated, scabrous on the margin, to 2 mm of diameter, rigidly sharp-pointed acute. Spikelet free, slider in flowering, the lateral pedicel of last flower to 12 mm long, frequently scabrid; glumes narrow, sub-equal, (30–) 32–38 mm long, green when immature to purple when mature with hyaline long-acuminate tips, 3 ribs smooth to finely scabrid; lemma slender, fusiform, 6.5–9.5 mm long, homogenously pubescent apex truncate, ciliate and aristated, with arista to 4 mm long; callus sharp and slender, 2–3 mm long, villous with adpressed white hairs; palea lanceolate 8–11 mm, dorsally pubescent, bifid; awn 7–9.5(10.5) cm long, persistent, bigeniculate, the first segment (column) ca. 2 cm long, twisted, scabrid-villous with ascending hairs to 5 mm long, unigeniculate, the second segment (rest or seta) to 7 cm, flexuous, angled, scabrous, gradually less scabrid up to tip; anthers 7.5–11 mm long. Caryopsis terete, fusiform, 6–8.5 mm long, brown to pale brown ( Figure 11 (b3–h3)).

Phenology:—Flowering March to June.

Habitat:—Open areas with calcareous and volcanic soils, below 2100 m a.s.l., forming espartals in arid areas with less than 500 mm of rainfall per year.

Distribution:—[Stenomediterranean-S]. In North Africa: Algeria, Morocco, Tunisia ( Figure 12 ). Expected in Libya.

3. Macrochloa tenacissima (Loefl. ex L.) Kunth (1829: 59) ( Figure 11 (b1–h1) & 12).

Type:— SPAIN. Hisp., Loefling 5.56b (lectotype LINN 94-7 !, designated by Vázquez et al. (1995: 185).

≡ Stipa tenacissima Loefl. ex L. (1755: 6) (Bas.).

≡ Lasiagrostis tenacissima (L.) Trinius & Ruprecht (1842: 94).

= Stipa tenacissima subsp. paucipila Barreña, Alcaraz & Rivera in herb.(G105240!).

= Stipa tenacissima subsp. kerguelenii Barreña, Alcaraz & Rivera , in herb. (G8473-28!).

Culm 80–180 cm tall, erect not geniculate at base, glabrous; prophylls aristated, plumose arista to 8 cm, pubescent to tomentose. Leaves with sheaths glabrous on the stem, free margin, scabrid; ligule to 2 mm, transform in line of hairs; vegetative blades culms to 65 cm long, convolute, abaxially glabrous, adaxially scabrous to villous striated, scabrous on the margin, up to 2.5 mm of diameter; fertile blades culms to 36 cm long, convolute, abaxially smooth, occasionally scabrous, adaxially scabrous to villous, striated, scabrous on the margin, to 2 mm of diameter, rigidly sharp-pointed acute. Inflorescence to 45 cm long, panicle lanceolate, falling, lax, the axis glabrous to scabrid, alternate to sub-verticillate branches, slender, sub-flexuous, smooth to scabrid, spikelet-bearing in all inflorescence. Spikelet free, slider in flowering, the lateral pedicel of last flower to 12 mm long, frequently scabrid; glumes narrow, sub-equal, 25–37(–39) mm long, green when immature to purple when mature with hyaline long-acuminate tips, 3 ribs smooth to finely scabrid; lemma slender, fusiform, 7–10.5 mm long, homogeny pubescent apex truncate, ciliate and aristated, with arista to 3 mm long; callus sharp and slender, 1–3 mm long, villous with adpressed white hairs; palea lanceolate 8–11 mm, dorsally glabrous, not bifid, Awn 5–9.5 cm long, persistent, twice-geniculate, the first segment (column) ca. 2.5 cm long, twisted, scabrid-villous with ascending hairs to 5 mm long, unigeniculate, the second segment (rest or seta) to 7 cm, flexuous, angled, scabrous, gradually less scabrid up to tip; lodicules 3, unequal, the two laterals 1.5–3 mm long, acute, lanceolate, 1–2 ribs, apex entire, the posterior lineal longer than laterals, to 0.3 mm long; anthers 7.5–12 mm long, apex apiculate, bearded with hairs up to 0.35 mm; stigma 2–3, plumose. Caryopsis terete, fusiform, 5–8 mm long, brown to pale brown ( Figure 11 (b1–h1)).

Phenology:—Flowering March to June.

Habitat:—Mostly open areas with calcareous soils, below 1700 m a.s.l., forming espartals in arid areas with less than 550 mm of rainfall per year.

Distribution:—[Stenomediterranean-Occidental]. In North Africa: Libya, Tunisia, Algeria and Morocco (Figure

12).

Figures

FIGURE 10. Geographic distribution of Macrochloa tenacissima (red mark) and, Macrochloa antiatlantica (blue mark) in North Africa (from checked herbarium sheets and selected bibliographical data (stars)).

FIGURE 11. Macrochloa. a. Plant habitus. b. Spikelets. c. Anthecium open + Awn. d. Awn section. e. Ligule (Sheet + Limb fractions). f. Awn fragment. g. Limb cross section. h. Anther apex. (1): M. tenacissima. (2): M. gabesensis subsp. gabesensis. (3): M. gabesensis subsp. kelibiae. (4): M. antiatlantica. Bars indicate 1 mm in d, f, g, and h; the rest 10 mm.

FIGURE 12. Geographic distribution of Macrochloa gabesensis: Macrochloa gabesensis subsp. gabesensis (red mark) and, Macrochloa gabesensis subsp. kelibiae (yellow mark) in North Africa (from checked herbarium sheets and selected bibliographical data (stars)).