Austronea oblongifolia Mart.

Martínez-Azorín, Mario, Dold, Anthony P., Crespo, Manuel B. & Vargas, María Ángeles Alonso, 2023, Austronea oblongifolia (Hyacinthaceae subfam. Urgineoideae), a new species from the Eastern Cape Province in South Africa, Phytotaxa 585 (1), pp. 48-54 : 49-52

Austronea oblongifolia Mart. -Azorín, A.P.Dold, M.B.Crespo & M.A.Alonso, sp. nov. ( Figs 1–2 )

Ab Austronea marginata characteribus foliorum affinis, sed hac valde diversa nempe folio solitario, synantho, 5–7 mm lato (non 1 vel raro 2 foliis, hysteranthis, latioribus, ad 9–15 mm), leviter striato, indistincte marginato, cum aequalibus minutisque papillis subtus et ad margines munito (non folio laevi, marginibus manifeste incrassatis, cartilagineis, dense et minute retrorso-scabridulis); pedunculo inflorescentiae brevissimo, 8–15 mm longitudine (haud multo longiore ad 100–200 mm); et pedicellis floralium brevioribus, 4–5 mm longitudine (non ad 5–10 mm). Planta vegetationis karroideae in solo arenoso-glareoso rubescente provinciae Capensis orientalis inventa.

Type:— SOUTH AFRICA. Eastern Cape: Fort Beaufort (3226): Normandale Farm, Bedford district , 20 km south of Bedford on R350 to Grahamstown (– CC), 660 m elevation, flat karroid plains with exposed bare rock sheets between fine reddish sandy soil covered with rocks and stones, 11 October 2022 (in flower and with immature fruits), A. P . Dold TD16062 (holotype GRA!) .

Herbaceous deciduous geophyte. Bulb hypogeal, ovoid, 15–25 × 15–22 mm, solitary, with compact scales and white membranous outer tunics. Roots fleshy, white, branched, 10–50 × 0.5–1 mm. Leaf solitary, usually synanthous and soon withering after flowering in fruit in both wild and cultivated plants, aerial portion 20–45 × 5–7 mm, appressed to ground, oblong, apiculate, leathery-succulent, flattened and slightly striate, dull dark green, margin undifferentiated,with minute, uniform papillae along margins and adaxial side, with white hypogeal leaf portion 8–15 mm long connecting to bulb scales. Inflorescence curved and appressed to ground in bud, raceme 1–3 mm long, capitate or subglobose, with 8–11 flowers; peduncle at anthesis 8–15 mm long, reddish purple, erect or flexuose, glabrous, smooth; pedicels 4–5 mm long at anthesis and in fruit, suberect to spreading, reddish purple, smooth; bracts ovate-lanceolate, 0.8–1.2 mm long, clasping pedicels, spurred, lowermost with broad, flat, papery spur 0.3–0.8 mm long, reddish purple. Flowers pentacyclic, trimerous, stellate, opening in morning and withering in evening, 1–3 flowers open at a time, flower buds reddish; tepals 6, entire, reddish (‘burnt orange’), with darker longitudinal central band on abaxial side, slightly glandulose at apex, biseriate, outer overlapping inner at base, free and connivent to form distinct cup along lower third and patent above; tepals ovate-oblong, 4.0–4.5 × 1.6–1.8 mm; outers with margins distally revolute at anthesis. Stamens 6, suberect, adnate to perigone for ca. 0.5 mm; filaments white, fleshy, lanceolate with attenuate apex, flat, 1.8–2.1 × 0.5–0.7 mm, smooth; anthers yellow, oblong, ca. 0.7 mm long before dehiscence, dehiscing by longitudinal slits, with yellow pollen. Ovary green, ovoid-oblong, truncate to style, ca. 2 × 1.5 mm; style white, columnar, erect, ca. 1.7 mm long, trigonous in transverse section; stigma small, trigonous, glandulose and slightly papillate. Capsule ovoid-globose, loculicidal, 6–8 × 5–7 mm, valves splitting to base, with withered perigone segments circumscissile below and forming an apical cap. Seeds 15–22 per capsule, black, glossy, 2.2–3.0 × 1.8–2.5 mm, trigonous in outline, tetrahedrally folded and narrowly winged along angles, testa loose and easily detachable from embryo, with colliculate testa cell walls.

Ethymology:—Named after the oblong morphology of the leaf.

Phenology: — Austronea oblongifolia flowers from September to October in the wild; mature fruits produced from November to December. Flowers short-lived, opening about midday and withering by dusk, 1–3 flowers open in one day.

Habitat: —This species is solitary, scattered in open exposed sandy areas around bare rock sheets near hill tops, between or beneath low karroid woody shrubs including Chrysocoma ciliata Linnaeus (1753: 841) , Felicia muricata Nees von Esenbeck (1832: 210) , and Pentzia globosa Lessing (1832: 266) . Succulents such as Chasmatophyllum musculinum ( Haworth 1826: 327) Dinter & Schwantes in Schwantes (1927: 18), Crassula corallina Thunberg (1778: 329) , Duvalia modesta Brown (1909: 1028) , Faucaria tuberculosa Schwantes (1926: 177) , and Trichodiadema intonsum Schwantes (1926: 188) share the habitat. The vegetation type is known as Bedford Dry Grassland ( Mucina & Rutherford 2006) and described as open, dry grassland. Grasses, such as Eragrostis curvula ( Schrader 1821: 2073) Nees von Esenbeck (1841: 397) , are however sparse in this micro-habitat, being more abundant along lower drainage lines.

Distribution:— Austronea oblongifolia is presently only known from the type locality at the farm Normandale, south of Bedford, in the Eastern Cape Province of South Africa. Further studies are needed to ascertain its real occurrence, which is probably overlooked by its cryptic appearance.

In their revision of Drimia sensu lato in southern Africa, under the species account of Drimia chalumnensis Dold & Brink (2004: 631) , Manning & Goldblatt (2018) suggest that the collection Van Jaarsveld 1119 (NBG) [corrected here to Van Jaarsveld 11119] from the farm Normandale may represent an undescribed species. Our work on living material from Normandale confirms this. Manning & Goldblatt (2018) also refer to the collection Zeyher 4223 (SAM) from ‘Zwartkopsrivier’ near Gqeberha (previously Port Elizabeth) in the same account. The latter collection includes three complete plants with inflorescences and a single canaliculate leaf of 30–50 × ca. 2 mm with acute apex, and their margins are somewhat thickened and differentiated from the blade. Further studies are needed to determine its taxonomic identity.

Diagnostic characters and taxonomic relationships:— Austronea oblongifolia is easily identified by the solitary bulb with compact scales; the single, flat, oblong, apiculate, appressed leaf with minute papillae on the adaxial side and the margin, the latter undifferentiated from the blade; the very short peduncle; the subcapitate, few flowered inflorescence; the lowermost bracts with a flat spur, and the reddish flowers with smooth filaments ( Figs 1–2 ).

Austronea oblongifolia resembles A. marginata in the overall leaf morphology, but the latter differs by the 1(2), hysteranthous, wider (9–15 mm wide), oblong to elliptical leaves with heavily thickened, cartilaginous, and densely and minutely retrorso-scabridulous margins; the much longer peduncle (100–200 mm long); the longer pedicels (5–10 mm long at anthesis); and its occurrence in fine-grained clay soils restricted to the Hantam and Roggeveld Plateaus ( Manning & Goldblatt 2007, 2018).

Austronea pulchromarginata differs from A. oblongifolia by the (1)2–4, elliptical to broadly elliptical or suborbicular, much wider leaves (15–25 mm wide), with a highly ornamented, duplex margin comprising a narrow, colliculate rim edged internally with a broader band, ± 0.5 mm wide, of closely packed, suberect or weakly retrorse trichomes ± 0.1 mm long; the much longer peduncle [(60) 150–300 mm long]; the many-flowered inflorescence (10–30 flowers); the longer pedicels (5–10 mm long at anthesis); and its occurrence in the northern regions of Namaqualand and the Richtersveld, in sandy or gravelly soils ( Manning & Goldblatt 2007, 2018).

Austronea ecklonii (= Drimia ligulata ), differs from A. oblongifolia by the 2–3(4), glabrous, longer and wider leaves[(20–)30–90 × (4–)6–10(–15) mm], with an obtuse apex and a simple, thickened (0.5 mm thick), cartilaginous, papillate or colliculate margin; the much longer peduncle [(60) 80–200 mm long]; the many-flowered inflorescence (5–30 flowers); the longer pedicels (5–10 mm long at anthesis); and its confinement to seasonally moist sandstone substrates at moderately high altitudes, between 500–1500 m elevation, in the western mountains of the Cape Fold Belt, flowering in December and January ( Manning & Goldblatt 2007, 2018).

Additional material studied (paratypes):— SOUTH AFRICA. Eastern Cape: Fort Beaufort (3226): Normandale , south of Bedford (-CC), rocky grassland, 20 September 1990 (in flower), E. van Jaarsveld 11119 ( NBG149311 !); Fort Beaufort (3226): Normandale Farm , Bedford district , 20 km south of Bedford on R350 to Grahamstown (-CC), 660 m elevation, flat karroid plains with exposed bare rock sheets between fine reddish sandy soil covered with rocks and stones, 14 October 2022 (in fruit), A.P.Dold TD16063 ( GRA!).

Figures

FIGURE 1. Austronea oblongifolia from the type locality (Normandale Farm, Eastern Cape, South Africa). a. Plant in flower; b. Inflorescence; c. Flowers in frontal and dorsal views; d. Dissected flower showing gynoecium, stamens and tepals; e. Leaves; f. Infructescence; g. Dehisced capsule; h. Seeds. Scale bars: a, e: 1 cm; b, f, g: 5 mm; c, d: 3 mm; h: 2 mm.

FIGURE 2. Austronea oblongifolia from the type locality (Normandale Farm, Eastern Cape, South Africa). a. Habitat at Normandale Farm; b. Leaf in habitat; c. Curved young inflorescence in cultivation; d. Detail of adaxial leaf surface and margin.