Austronea linearis Mart.

Martínez-Azorín, Mario, Crespo, Manuel B., Alonso-Vargas, María Ángeles, Dold, Anthony P., Pinter, Michael & Wetschnig, Wolfgang, 2018, Austronea (Asparagaceae, Scilloideae), a new genus from southern Africa, including the description of seven new species, Phytotaxa 365 (2), pp. 101-129 : 116-118

4. Austronea linearis Mart. -Azorín, M.B.Crespo & A.P.Dold, sp. nov. ( Fig. 9 )

Ab Austronea vermiformi affinis foliis coriaceis linearis atroviridisque, sed hac multo diversa nempe foliis usque ad 3 (nec semper solitariis), minute papillosis (nec laevibus), 2–3 mm lat. (nec 3–6 mm lat. et magis carnosis), synanthis vel proteranthis (nec semper proteranthis).

Type:— SOUTH AFRICA. Western Cape. Ladismith (3321): ca. 3 km E of Calitzdorp, on main road to Oudtshoorn (- DA), elev. 350 m, 28 September 2011 in flower and fruit, M. Martínez-Azorín, J. Vlok, A. P.Dold & A. Martínez-Soler MMA928 (holotype, GRA!; isotype, ABH59622 !) .

Herbaceous deciduous geophyte. Bulb hypogeal, solitary, ovoid to subglobose, 14–28 × 13–27 mm, extended into a very short hypogeal neck, with white membranous outer tunics and white fleshy tightly packed inner tunics. Roots fleshy, white, branched, 8–50 × 0.6–1 mm. Leaves 1–3, synanthous or withered at flowering time, aerial portion 38–90 × 2–3 mm, narrowly linear and elongated, flattened, sometimes slightly canaliculated at the base, leathery, dull dark green, apparently smooth but covered by minute papillae along the whole surface when dry (visible with magnifying glass), prostrate to suberect, straight or slightly curved, with a white hypogeal leaf portion of ca. 1 cm long conecting to the bulb neck. Inflorescence nodding in bud, raceme 2–5 mm long, capitate or subglobose, with 6–25 flowers; peduncle 8–16 cm long, purple, erect or flexuose, glabrous, smooth or rarely minutely papillose at the base; pedicels 10–15 mm long at anthesis, suberect to spreading, smooth; bracts ovate-lanceolate, 0.8–1 mm long, clasping the pedicels, spurred, the lowermost with a spur of 1.5–2 mm long, membranous, white with a central darker band. Flowers pentacyclic, trimerous, stellate, opening about noon and withering in the evening, 1–3 flowers open at a time, flower buds red; tepals 6, entire, reddish, with a darker longitudinal central band on the abaxial side, slightly glandulous at the apex, biseriate, outer overlapping inner at the base, connate at the base for ca. 1.5 mm to form a distinct cup, free portions patent; outer tepals ovate, 4.8–5 × 1.9–2 mm; inner tepals ovate-lanceolate, 4.7–5 × 1.8–2 mm, both inner and outer with margins somewhat revolute longitudinally at anthesis. Stamens 6, suberect or slightly spreading, adnate to perigone for ca. 1.5 mm; filaments white, fleshy, subterete and attenuate to the apex, 1.9–2.1 × 0.3 mm, smooth; anthers yellow, oblong, ca. 0.8 mm long before dehiscence, dehiscing by longitudinal slits, with yellow pollen. Ovary green, ovoid, truncate to the style, 2.4–2.6 × 1.8 mm; style white, columnar, 1.2 mm long, trigonous in transversal section; stigma small, glandulose and slightly papillate. Capsule ovoid-globose, loculicide, 6–9 × 5–6 mm, valves splitting to the base, with the withered perigone segments circumscissile below and forming an apical cap. Seeds up to 30 per capsule, black, shining, ca. 3 × 2 mm, commonly trigonous in outline, tetrahedrally folded and narrowly winged along the angles, with subovoid embryo ending into a long filamentous hilum, testa loose and easily detachable from the endosperm, with colliculate testa cell walls.

Etymology:—Name alluding to the linear leaves characteristic of this species.

Phenology:— Austronea linearis flowers around September–October in the wild; fruits appear in NovemberDecember.

Habitat:—This species occurs on open patches of vegetation with stony ground in the Succulent Karoo and Nama Karoo biomes ( Mucina & Rutherford 2006).

Distribution:— Austronea linearis is known from southern Namibia and north western Northern Cape Province of South Africa as far south as the Little Karoo in Western Cape and the north-eastern regions of the Eastern Cape Province ( Fig. 10 ). Large gaps among the cited populations exist and further studies are needed to evaluate the real extension of the distribution of this species.

Diagnostic characters and taxonomic relationships:— Austronea linearis was already recognised as an undescribed species, as “ Drimia sp. nov. ”, in a photograph included in the CD attached to the book “Plants of the Klein Karoo” by Vlok & Schutte-Vlok (2010). Austronea linearis shows similar flowers to those of A. ecklonii , A. marginata , A. pulchromaginata and A. vermiformis but it differs in the 1–3, leathery, dull dark green, narrowly linear leaves, only 2–3 mm wide, which are synanthous or withered at flowering time, apparently smooth but covered by minute papillae along the whole surface under magnification when dry. The closest species, as far as the occurrence of the linear leaves is concerned, are A. vermiformis and A. trichophylla . However, these two species always show a solitary leaf, smooth and thicker in A. vermiformis , and lacking papillae and being distinctly hairy in A. trichophylla . Moreover, A. vermiformis is restricted to the western regions of the Western Cape Province and A. trichophylla is only known from the surroundings of Grahamstown, in the Eastern Cape Province, whilst A. linearis occurs from the inland western areas on the Eastern Cape Province and the Little Karoo to north-western Northern Cape Province and southern Namibia. As mentioned above, the concept of A. vermiformis by Manning & Goldblatt (2007) is very wide and includes several populations that are here segregated as distinct species. Among them, the populations from the Little Karoo and Bushmanland are included in A. linearis . However, our field work revealed some variability in the studied populations. The populations from southern Namibia and Bushmanland (Northern Cape) constantly show a single leaf which is usually short and withered at flowering time whilst those from the Little Karoo and southern South Africa present 1–3 leaves, commonly 2, which are usually longer and mostly synanthous. However, inflorescence and flower sizes and morphology are almost identical among all those populations. That, together with the constant micropapillate leaves, support the acceptance of a single species. Further studies are required to evaluate the variability of these characters across its whole distribution.

Additional material studied (paratypes):— NAMIBIA. Warmbad (2818): Warmbad Dist. , Witsand (- DB), elev. 950 m, 17 July 2005, P. Bruyns 10093 ( NBG277883 !) ; Witputz (2716): koppie east of mine at Rosh Pinah, on Namuskluft (- DD), elev. 454 m, 29 September 2004 (in flower), C. A. Mannheimer, Maggs-Kölling, G. L. et al. CM2661 ( NBG!, PRE0865332 !, WIND83726 !) ; Oranjemund (2816): Distrikt Lüderitz-Süd, Obibberge (- BA), 20 September 1972 (in flower), H. Merxmüller & W. Giess 28593 ( PRE!). SOUTH AFRICA. Northern Cape: Springbok (2917): S of Steinkopf, ca. 2.5 km S of Spitzkop , ca. 500 m W of N7 , quartzitic outcrop (- BD), elev. 842 m, 29 July 2016 (in leaf), M. Martínez-Azorín, M. B. Crespo, M. A. Alonso, J. L. Villar, A. Vicente, J. Moreno & A. Terrones MMA1544 ( ABH74326 !) ; Gamoep (2918): Naib se Berg, eastern end, east of farm (- AD), elev. 827 m, 29 September 2015 (in flower), M. Martínez-Azorín, M. Pinter, M. B. Crespo & M. A. Alonso MMA1250 ( ABH74102 !) ; Gamoep (2918): Naib se Berg, west of farm at eastern end, slopes going to south-facing entrance of main kloof (- AD), elev. 877 m, 29 September 2015 (in flower), M. Martínez-Azorín, M. Pinter, M. B. Crespo & M. A. Alonso MMA1253 ( ABH74105 !) ; Gamoep (2918): Naib se Berg, central section, on the way to south-facing entrance of main kloof (- AD), elev. 916 m, 29 September 2015 (in flower), M. Martínez-Azorín, M. Pinter, M. B.Crespo & M. A. Alonso MMA1262 ( ABH74114 !) ; Pofadder (2918): Pofadder, Bushmanland (- AB), 14 October 1954 (in leaf), ex hort on 13 May 1957 (in flower), E. Esterhuysen 23640a ( BOL!) ; Prieska (2922): Griquastad District , Rudesheim (- DD), elev. 1400 m, 15 April 2003, P. Bruyns 9415 ( NBG0212212 -0!). Western Cape: Montagu (3320): Laingsburg C. P., Witteberg, Whitehill, northern slope (- BA), elev. 3500 feet, 24 October 1943 (in flower), R. H. Compton 15252 ( NBG73279 !) ; Montagu (3320): 13.5 km east of Bonnievale, near Drew (- CC), P. L. Perry s.n. ( NBG123415 !) ; Montagu (3320): near Montagu (- CC), M. R. L. 4600 ( BOL!) ; Ladismith (3321): Matjiesvlei, at bottom of pass, near Elandspad at Gamkaspoort (- BC), elev. 1600 feet, 18 September 1985, J. H. J. Vlok 1148 ( NBG140516 !) ; Ladismith (3321): ca. 11 km SW of Calitzdorp, Groenefontein Nature Reserve , at eastern foot of mountain pass (- DA), elev. 326 m, 29 September 2011 in flower, M. Martínez-Azorín, A. P. Dold & A. Martínez-Soler MMA963 ( GRA!, ABH59651 !) ; Ladismith (3321): Farm Droogkraal, 30 km NW of Oudtshoorn (- BD), 1 October 1980 (in flower), A. Bean s.n. ( NBG123416 !) ; Ladismith (3321): Road to Rooiberg pass, southwest of Radleight (- DA), elev. 1000 feet, 6 October 1971 (in flower), E. G. H. Oliver 3665 ( NBG!) ; Ladismith (3321): Calitzdorp District , Farm NE of Town (Besemkop) (- DA), elev. 370 m, 29 September 2006, P. M. Burgoyne & M. Warrington 10677 ( PRE843054 !) ; Ladismith (3321): Redstone Hills farm (- DB), 18 October 2017 (in flower), N. Crouch s.n. (Photo!) ; Oudtshoorn (3322): Oudtshoorn Div., 1 m NW of Cango Caves (- AC), 3 November 1928 (in flower and fruit), J. B. Gillett 1961 ( BOL!, NBG288146 !) ; Oudtshoorn (3322): Rust en Vrede , E of Cango (- AD), 15 October 2006 (in flower), A. Harrower 3158 ( NBG206909 !) ; Oudtshoorn (3322): south of turnoff to Kruisrivier on R62 , ca. 20 km west of Oudtshoorn (- CA), elev. 248 m, 29 September 2011 in flower, M. Martínez-Azorín, A. P. Dold & A. Martínez-Soler MMA961 ( ABH!) ; Oudtshoorn (3322): 1.5 km east of Oudtshoorn , on road to De Rust (- CA), elev. 372 m, 30 September 2011 in flower, M. Martínez-Azorín, A. P. Dold & A. Martínez-Soler MMA972 ( GRA!, ABH59608 !) ; Oudtshoorn (3322): 3 km east of Oudtshoorn , on road to De Rust (- CB), elev. 358 m, 30 September 2011 in flower, M. Martínez-Azorín, A. P. Dold & A. Martínez-Soler MMA975 ( GRA!, ABH59626 !) ; Oudtshoorn (3322): Oudtshoorn , 3 km from Dysseldorp on road to Herold (- CB), elev. 400 m, 1 October 1989, N. P. Barker 683 A ( PRE743900 !). Eastern Cape: Hanover (3124): 2.2 km NW of Nieu Bethesda (- DC), elev. 1435 m, 14 October 2011 in flower, M. Martínez-Azorín & A. Martínez-Soler MMA1008 ( GRA!, ABH59359 !) .

Figures

FIGURE 9. Austronea linearis Mart.-Azorín et al. from E of Calitzdorp (type locality), Western Cape, South Africa, in flower in the wild on 28 September 2011 corresponding to MMA928, fruits corresponding to MMA963. A. Inflorescence; B. Flowers, frontal and dorsal views; C. Flower and dissected flower in lateral view; D. Mature capsules, lateral views; E. Plants in flower; F. Young nodding inflorescence; G. Leaves. Scale bars: A, D–G: 1 cm; B–C: 3 mm.

FIGURE 10. Distribution of Austronea species in southern Africa. A. linearis Mart.-Azorín et al. (red circle), A. olifanta Mart.-Azorín et al. (blue square) and A. pinguis Mart.-Azorín et al. (yellow triangle).