Austronea pinguis 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 : 123-125

7. Austronea pinguis Mart. -Azorín, M.B.Crespo, M.Pinter & M.A.Alonso, sp. nov. ( Fig. 13 )

Ab Austronea acarophylla et A. vermiformi affinis folia solitaria, incrassata vel succulenta atque inflorescentia subcapitata, sed his bene diversa et facile distinguitur. A priore folia 15–25(40) × 5–9 mm, majora (in illa 6–14 × 1–4 mm) et inflorescentiae pedunculo 7–14 cm, multo longiore differt. A posteriore precipue folia breviora et latiora (in illa 35–70 × 2–5 mm) inter alteros characteres discrepat.

Type:— SOUTH AFRICA. Western Cape. Montagu (3320): Rooinek Pass, ca. 18 km south of Laingsburg on R323 (- BD), elev. 759 m, ex hort at University of Alicante on 4 May 2018 in flower, M. Martínez-Azorín, M. Pinter, M. B. Crespo & M. A. Alonso MMA1342b (holotype: GRA!; isotype: ABH!) .

Herbaceous deciduous geophyte. Bulb hypogeal, solitary, ovoid to subglobose, 15–22 × 16–27 mm, slightly depressed in mature plants, extended into a hypogeal neck up to 20 mm long, with white membranous outer tunics and white fleshy tightly packed inner tunics. Roots fleshy, white, branched, 10–20 × 0.6–1 mm. Leaf solitary, withered at flowering time, aerial portion 15–25(40) × 5–9 mm, clavate, succulent, subterete to slightly flattened, leathery, dull dark green, smooth, suberect, with a white hypogeal leaf portion of 10–25 mm long conecting to the bulb neck. Inflorescence nodding in bud, raceme 3–6 mm long, capitate or subglobose, with 10–25 flowers; peduncle 7–14 cm long, reddish-brown, erect or flexuose, glabrous, smooth; pedicels 5–8 mm long at anthesis, suberect to spreading, smooth; bracts ovate-lanceolate, 0.7–0.9 mm long, clasping the pedicels, spurred, the lowermost with a spur of 0.6–0.8 mm long, membranous, purplish 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 1–1.5 mm to form a distinct cup, free portions patent; outer tepals ovate, 3.5–4.5 × 1.3–1.5 mm; inner tepals ovate-lanceolate, 3.4–4.3 × 1.2–1.4 mm, both inner and outer with margins somewhat revolute longitudinally at anthesis. Stamens 6, suberect, adnate to perigone for ca. 1 mm; filaments white, fleshy, subterete and attenuate to the apex, 1.8–2.3 × 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, 1.8–2 × 1.6 mm; style white, columnar, somewhat curved, 1.2 mm long, trigonous in transversal section; stigma small, glandulose and slightly papillate. Capsule and seeds unknown.

Etymology:—Name alluding to the short and succulent single leaf characteristic of this species.

Phenology:— Austronea pinguis flowers around December in the wild. In cultivation in the northern hemisphere (University of Alicante, Spain) it flowers around May.

Habitat:—This species is found on open patches of vegetation with stony ground mostly in the Succulent Karoo and Nama Karoo biomes ( Mucina & Rutherford 2006). The populations around Laingsburg are located in the SKv6 Koedoesberge-Moordenaars Karoo and the Nkl1 Gamka Karoo vegetation types, characterized by indistinct aseasonal rainfall (mean annual precipitation ranging from 100 to 240 mm), with a slight optimum in winter (March and May- August), with a mean annual temperature of 16º C and relatively high incidence of frost. The disjunct population around Richmond occurs in NKu4 Eastern Upper Karoo vegetation type and rainfall occurs mainly in autumn and summer, peaking in March ( Mucina & Rutherford 2006).

Distribution:—Most populations of Austronea pinguis are located around Laingsburg, north of the Swartberge mountain range, extending inland to the southern Roggeveld, Beaufort West and Richmond ( Fig. 10 ).

Diagnostic characters and taxonomic relationships:— Austronea pinguis was first recognised as an undescribed species, as “ Drimia sp nov Rouxpos”, in a photograph included in the CD attached to the book “Plants of the Klein Karoo” by Vlok & Schutte-Vlok (2010). Austronea pinguis is easily distinguished by the single, short and succulent leaf (15–25(40) × 5–9 mm) and the subcapitate inflorescence borned on an elongated peduncle. This species seems to be related to A. acarophylla and A. vermiformis based on the single, thickened or succulent leaf. However, A. acarophylla differs by the smaller leaf (6–14 × 1–4 mm) and much shorter peduncle of inflorescence ( Brink & Dold 2003) and A. vermiformis shows a much longer and thinner leaf (35–70 × 2–5 mm), among other characters ( Manning & Goldblatt 2007).

Additional material studied (paratypes):— SOUTH AFRICA. Western Cape. Sutherland (3220): Laingsburg dist., Wilgerboom (- DB), elev. 1100 m, 30 May 2005 in leaf, flowers end of December, P. V. Bruyns 9998 ( NBG0267458 - 0!) ; Beaufort West (3222): Stolshoek, Karoo National Park , W of Beaufort West (- AD), elev. 1250 m, 13 September 1989 (in flower), P. V. Bruyns 3977 ( BOL2546 !) ; Montagu (3320): Rooinek Pass, ca. 18 km south of Laingsburg on R323 (- BD), elev. 759 m, 3 October 2015 in leaf, M. Martínez-Azorín, M. Pinter, M. B. Crespo & M. A. Alonso MMA1342 ( ABH74912 !) ; Montagu (3320): Rooinek Pass, south of Laingsburg (- BD), 30 August 2012 in leaf, J. Slade (Photo!) ; Ladismith (3321): Spitskopvlakte , 20 km E of Laingsburg (- AA), rocky shale flats, 12 May 2011 in leaf, N. Helme (Photo on iSpot at https://www.ispotnature.org/communities/southern-africa/view/observation/366351/drimiae-of-laingsburg) ; Ladismith (3321): near Rouxpos, on road from Laingsburg to Ladismith (- AC), 13 August 2007 in leaf, J. Vlok s.n. (Photo in Vlok & Schutte-Vlok 2010). Northern Cape. Victoria West (3123): Richmond, slopes ca. 500 m north of town (- BD), D. Human s.n. (Photo!) ; Hanover (3124): Messfontein, Richmond (- AA), 13 April 2016 (in leaf), Dewidine (Photo on iSpot: https://www.ispotnature.org/communities/southern-africa/view/observation/614489/ drimia-single-leaf!) .

Figures

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).

FIGURE 13. Austronea pinguis Mart.-Azorín et al. from S of Laingsburg, (type locality), Western Cape, South Africa; in cultivation on 4 May 2018 corresponding to MMA1342b (A–D); and on 17 April 2018 (E); from the type locality on 30 August 2012 (F); and on 3 October 2015 (G–H). A. Inflorescence; B. Flowers, frontal and dorsal views; C. Flower and dissected flower in lateral view; D. Gynoecia, lateral views; E. Plant in flower with nodding young inflorescence; F. Leaf in habitat (Photograph by J. Slade); G. Bulbs and withering leaves; H. Leaves starting to wither prior flowering. Scale bars: A, E, G–H: 1 cm; B–D: 1 mm.