Diplotaxis australis Martínez-Laborde, 2018

Martínez-Laborde, Juan B., 2018, Taxa related to Diplotaxis virgata (Brassicaceae) in northwest Africa, Phytotaxa 371 (3), pp. 205-216 : 210-213

Diplotaxis australis Martínez-Laborde , sp. nov. ( Fig. 1 )

Type:— MOROCCO. Region Drâa-Tafilalet : Ouarzazate: prope oppidulum Amerzgane, ad 1300 m, in clivosis siccis, 31 May 1985, Blanché, Fernández Casas, Molero, Montserrat & Romo 9644 (holotype BC 813229 , rightmost specimen; isotype SEV!)

≡ D. virgata subsp. australis Martínez-Laborde (1988: 316 , unpublished; Gómez-Campo 1990: 22, nomen nudum).

Diagnosis: —It differs from Diplotaxis virgata and Diplotaxis sahariensis mainly by its hairs, predominantly retrorse on stems, generally antrorse on leaves, and more or less flexuose, pointing in several directions and apparently disorderly arranged on sepals; as well as by its anthers, with a purple spot at tip (to be observed in vivo before anthesis).

Annuals, 10–50 cm tall. Stems erect, foliose, ± hirsute at least at base, with predominantly retrorse hairs. Leaves ± hairy, hairs 0.3–0.5 mm long, generally antrorse, especially towards the apex, rarely retrorse towards the base. Lower leaves with petiole 5–50 mm long; blade 20–130 × 10–70 mm, elliptic to scarcely obovate in outline, margin usually remotely dentate, generally lobate to pinnatisect, rarely subentire; lateral segments 1–3 pairs, ± elliptical, apical segment generally much larger, sometimes lobate towards the base, attenuate. Cauline leaves smaller, uppermost leaves narrowly ovate, with 1–2 lobes at base. Sepals 3.5–4.5 mm long, densely to sparsely hairy, hairs mostly more or less flexuose, pointing in several directions and apparently disorderly arranged. Petals 6.5–9.5 × 3.0– 4.5 mm, claw distinct, limb yellow, obovate to slightly oblong. Median stamens 4.5–5.0 mm long, lateral stamens ± 3.5 mm long, anthers 1.4–1.6 mm long, with a purple spot at tip (to be observed in vivo, before anthesis). Ovary with ± 30–50 ovules per locule. Fruiting pedicels 4–16 mm, erect-patent to patent, hairless or provided with generally ± retrorse hairs. Siliques (13–)20–30(–35) × 1.0– 1.7 mm, erect-patent to patent, rarely suberect, elliptical to oblong in outline; carpophore 0.3–0.6(–1.1) mm; valves flattened; stylar segment (1–)1.5–5.0(–6.5) × 0.8–1.2 mm (equivalent to approximately 1/10–1/5 of the total length of the silique), linear to attenuate, flattened, 1- to 3-veined, containing 1–3 seeds (or aborted ovules), stigma ± capitate. Seeds in two rows per locule, 0.6–0.9 × 0.4–0.6 mm, ovoid to ellipsoid.

Distribution: — Diplotaxis australis is endemic to southwestern Morocco and is distributed south of the High Atlas in Regions Souss-Massa and Guelmim-Oued Noun, from the Atlantic coast eastwards up to at least Agdz (Zagora province), at elevations between 0 and 1400 m above sea level.

Additional specimens examined:— MOROCCO. Region Souss-Massa: Agadir , 15 January 1970, Kaae ( C) ; ibidem, 25 January 1970, Kaae ( C) ; ibidem, 18 March 1972, P. & J. Davis 53486 ( BM, E, RNG) ; ibidem, March 1935, Thretewy 76 ( BM, K) ; ibidem, steppe, 200 m, 25 December 1983, Lewalle 10876 ( BM) ; Agadir-m-Ighir , in ruderatis, 12 April 1931, Maire s.n. ( MPU) ; Agadir, prope oppidulum Tafraute , 970 m, in dumosis secus viam, 26 May 1985, Blanché, Fernández Casas, Molero, Montserrat & Romo 9348 ( BC 807550 , BC 813651 ) ; 10 km N of Agadir , 1 April 1974, Miller & al. 416 ( RNG) ; bords de l’Oued Tamerahrt, à 10 km au N d’Agadir , 2 July 1885, de Campou s.n. ( P) ; plaine de Ksima , 2 April 1922, Maire s.n. ( MPU) ; ad ripas fluminis Massa , in rupestris arenaceis, 3 April 1934, Maire & Wilczek s.n. ( MPU, P) ; Tafraoute, to Souk Tleta de Tasserirt , 1300–1400 m, 27 March 1969, Davis 48801 ( BM) ; Ammeln Valley, ca. Tafraoute , 29 March 1972, Davis 53858 ( E, RNG) ; Taroudant , champs irrigués, 17 April 1922, Maire s.n. ( MPU) ; Taroudant , vers le Ras-el-Oued, sous les arganiers, 14 April 1931, Jahandiez 146 ( BM, K) ; in arganietis clivi septentrionalis Anti-Atlantis supra Tiout , 700 m, solo lapidoso calcareo, 5 April 1934, Maire & Wilczek s.n. ( MPU) ; in Anti-Atlante: in arganietis lapidosis calcareis prope Tiout , 600–900 m, 19 April 1931, Maire s.n. ( MPU) ; 6 km N of Tiznit , ca. El-Mader-El-Kebir, 3 April 1974, Miller & al. 541 ( BM, RNG) ; Montagnes de Siggrat et Ghiliz, Sud-Ouest du Maroc, 1876, Mardoché , Herb. Cosson ( P). Region Drâa-Tafilalet : 2 km E de Agdz, 4 May 1986, Martínez-Laborde 328 ( MA 01-00916874 ) ; Ait Saoun, ca. 3 km westl. Oase am Trockental , 11 March 1992, Flügel M 97 ( B). Region Guelmim-Oued Noun: Asserarid [Asserir, SE of Guelmim], 1875, Mardoché s.n. ( P) ; Iter Ifniense, inter El Mers et El Had de Bifurna , 28 April 1935, Font Quer s.n. ( BC 111698 ) ; in depressis cultis inter Labier [Labyar] et Notfia , 1 April 1933, Maire s.n. ( MPU) ; in lapidosis arenaceis Anti-Atlantis prope Taghjicht , 700 m, 6 April 1935, Maire & Wilczek s.n. ( MPU) ; Tifernit et Ida Oubakil, district de Tazeroualt, 1876, Mardoché ( P) ; Uad sidi Ifni , 9 April 1935, Font Quer s.n. ( BC 111703 ) ; Ifni-Uad Areksis , 7 May 1935, Font Quer s.n. ( BC 111699 ) ; in cultis prope Sidi Ifni , 23 June 1934, Caballero s.n. ( MA 46367 ) ; Oued Noun , March–June 1936, Ollivier s.n. ( MPU) ; 20–30 km S of Goulimine, 50–100 m, 21 March 1972, P. & J. Davis 53624 ( BM, E, RNG). Specimens obtained from cultivated material . SPAIN. Madrid: Ciudad Universitaria, spring 1985, Martínez-Laborde 194, culta ex semina BGV-UPM 3646 ( MA 488559 ) ; ibidem, spring 1985, Martínez-Laborde 195, culta ex semina BGV-UPM 2973 ( MA 488590 ) ; ibidem, spring 1985, Martínez-Laborde 196, culta ex semina BGV-UPM 4064 ( MA 488592 ) ; ibidem, spring 1985, Martínez-Laborde 199, culta ex semina BGV-UPM 2976 ( MA 488594 ) ; ibidem, spring 1985, Martínez-Laborde 197, culta ex semina BGV-UPM 2977 ( MA 488591 ) ; ibidem, spring 1985, Martínez-Laborde 198, culta ex semina BGV-UPM 2991 ( MA 488593 ) ; ibidem, spring 1985, Martínez-Laborde 200, culta ex semina BGV-UPM 1099 ( MA 488595 ) ; ibidem, spring 1985, Martínez-Laborde 201, culta ex semina BGV-UPM 3003-UPM ( MA 488557 ) ; ibidem, spring 1985, Martínez-Laborde 206, culta ex semina BGV-UPM 1480 ( MA 488558 ) ; ibidem, spring 1985, Martínez-Laborde 207, culta ex semina BGV-UPM 2980 ( MA 488589 ) ; ibidem, spring 1985, Martínez-Laborde 208, culta ex semina BGV-UPM 5540 ( MA 488635 ) .

Cultivated material. BGV-UPM 1099, BGV-UPM 1480, BGV-UPM 1498, BGV-UPM 1943, BGV-UPM 2973 BGV-UPM 2976, BGV-UPM 2977, BGV-UPM 2980, BGV-UPM 3003 BGV-UPM 3646, BGV-UPM 5540, BGV-UPM 7514.

Observations: —Of the two groups of populations close to D. virgata previously distinguished by Martínez-Laborde & Gómez-Campo (1993), those growing in southwestern Morocco south of the High Atlas have a distinct pubescence, mostly retrorse-appressed and apparently disorderly arranged on sepals. They have not been described or named so far and therefore constitute a new species.

Note 1: —Several specimens belonging to D.australis were cited by Nègre(1960) under D. virgata var. cavanillesiana f. tenuirostris and f. platystylos .

Note 2: — Diplotaxis australis belongs to sect. Rhynchocarpum.

Identification key for North African taxa of the Diplitaxis virgata -group:

1. Hairs on sepals more or less flexuose, pointing in different directions and apparently disorderly arranged, those on stems mostly retrorse. Anthers yellow, with a purple spot on tip (to be observed in vivo, before anthesis) .............................. Diplotaxis australis

- Hairs on sepals straight, patent, those on stems patent or little retrorse. Anthers yellow throughout, without a purple spot on tip...............................................................................................................................................................................................................2.

2. Hairs rather soft, gentle when touched. Stylar segment of fruit 1.2–2.5(–3.7) mm long, equivalent to approximately 1/20–1/10 of the total length of the silique ............................................................................................................................ Diplotaxis sahariensis

- Hairs hirsute, stiff (at least on stems). Stylar segment of fruit (2.2–)3–6(–7) mm long, equivalent to ± 1/10–1/5 of the total length of the silique......................................................................................................................................................................................3.

3. Hairs on leaves patent. Siliques 18–29(–35) mm long, stigma ± capitate ...................................... Diplotaxis virgata subsp. virgata

- Hairs on leaves at least in part ± reclining. Siliques (22–)30–37(–47) mm long, stigma ± depressed, V-shaped ............................... .................................................................................................................................................. Diplotaxis virgata subsp. tenuirostris

Figures

FIGURE 1. Diplotaxis australis. A. Habit. B. Cauline leaf. C. Stem hairs. D. Top of flowering branch. E. Flower bud showing hairs on sepals. F. Siliques. Scale bars: A–B = 1 cm; C–F = 1 mm. All drawn from the type, BC 813229. Illustration by Marta Chirino.