Austronea densiflora 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 : 109-111

1. Austronea densiflora Mart. -Azorín, M.B.Crespo & A.P.Dold sp. nov. ( Fig. 5 )

Ab Austronea ecklonii affinis folio ad marginem incrassato colliculato papillis minutissimis inconspicuis munito, sed hac bene diversa folio solitario (nec 2–4); inflorescentia et pedunculo multo brevioribus quam folio subaequantibus vel brevioribus (nec valde longioribus), et floribus breviter penduculatis (usque ad 3 mm per anthesin) in racemo densissimo dispositis (nec subcorymbosis et longipedunculatis).

Type:— SOUTH AFRICA. Western Cape. Oudtshoorn (3322): Oudtshoorn, Grootkop Nature Reserve , NE of Oudtshoorn (- CA), elev. 415 m, 28 September 2011 (in flower), M. Martínez-Azorín, J. Vlok, A. P.Dold & A. Martínez-Soler MMA891 (holotype, GRA!; isotype, ABH59705 !) .

Herbaceous deciduous geophyte.Bulb hypogeal, ovoid, large and succulent, 30–50 × 22–35mm, usually forming clumps and some producing two inflorescences per bulb, not extended into a hypogeal neck, with pale brown membranous outer tunics and white fleshy tightly packed inner tunics. Roots fleshy, white, branched, 10–80 × 1 mm. Leaf solitary, suberect, withered or almost withered at flowering time, aerial portion 20–80 × 10–16 mm, lorate-oblong, rounded distally, flat, slightly curved, sometimes cucullate at the apex, dull dark green, leathery, smooth, margins slightly thickened and revolute, covered by minute papillae, with a short white hypogeal leaf portion conecting to the bulb. Inflorescence erect, as long as or usually shorter than leaves, raceme 10–12 mm long, dense, with 12–22 flowers; peduncle 1.8–2.5 cm long, erect, somewhat sinuous, purple, smooth, glabrous; pedicels up to 3 mm long at anthesis, patent to suberect; bracts ovate-lanceolate, ca. 2 mm long, clasping the pedicels, shortly spurred, the lowermost with a short curved outgrowth of 0.2 mm long, membranous, purplish. 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, white with a reddish tinge on the adaxial side, reddish with a darker longitudinal central band on the abaxial side, slightly glandular at the apex, biseriate, inner and outers overlapping at the base, connate for ca. 1 mm to form a slight cup, free portions spreading; outer tepals narrowly lanceolate-oblong, 4.7–5.1 × 1.7–1.9 mm, flat; inner tepals narrowly ovate, 4.8–5.2 × 1.8–2 mm, flat. Stamens 6, erect, adnate to perigone for ca. 1 mm; filaments white, fleshy, flat, narrowly triangular, 2.8–3.2 × 0.7–0.9 mm, smooth; anthers yellow, oblong, ca. 1 mm long before dehiscence, dehiscing by longitudinal slits, with yellow pollen. Ovary pale green, ovoid to subglobose, somewhat truncate to the style, 2.6–2.8 × 2 mm; style white, columnar, 1.9–2.1 mm long, slightly deflexed and sinuous, trigonous in transversal section; stigma small and slightly papillate. Capsule and seeds unknown.

Etymology:—Named after the dense inflorescence with very short flower pedicels.

Phenology:— Austronea densiflora flowers in September–October in the wild.

Habitat:—This species occurs in patches of open succulent vegetation on stony ground where plants are sheltered by rocks. It is restricted to the Little Karoo region and occurs in SKv11 Eastern Little Karoo and AT2 Gamka thicket vegetation types, characterized by indistinct aseasonal rainfall (mean annual precipitation ranging from 100 to 500 mm), with a slight optimum in March and pronounced drought period in summer (December–January), and with a mean annual temperature of 17º C and fairly frequent frost ( Mucina & Rutherford 2006).

Distribution:— Austronea densiflora appears to be mainly restricted to the Little Karoo in the Western Cape Province of South Africa, with a disjunct population near Kareedouw in the Eastern Cape Province ( Fig. 6 ).

Diagnostic characters and taxonomic relationships:— Austronea densiflora was already recognised as an undescribed species, as “ Drimia sp. nov. ”, on page 83 of “Plants of the Klein Karoo” by Vlok & Schutte-Vlok (2010). Austronea densiflora is easily distinguishable by the combination of large, hypogeal bulbs, forming clumps; the solitary, lorate-oblong, rounded, leathery, smooth leaf with margins slightly thickened and revolute, covered by minute papillae; the very short inflorescence being as long as or usually shorter than leaves; peduncle 1.8–2.5 cm long, smooth and glabrous; raceme dense, 10–12 mm long; pedicels up to 3 mm long at anthesis; flowers stellate, white with a reddish tinge; and tepals 4.7–5.2 mm long, connate for ca. 1 mm. Peduncle in A. densiflora is deviant in the genus in being very short, only shared by A. acarophylla and A. chalumnensis , but the 2 latter species differ in distinct leaf morphology ( Brink & Dold 2003, Dold & Brink 2004). Regarding leaf morphology, the wide, flat leaf of A. densiflora resembles in general terms those of A. ecklonii (= D. ligulata ), A. pulchromarginata and A. marginata . However, those three latter species clearly differ by distinct leaf shape and indumentum of leaf margin together with allopatric distribution ( Manning & Goldblatt 2007). Within those species, the closest to A. densiflora seems to be A. ecklonii , based on the thickened leaf margin colliculate or with minute, undifferentiated papillae. However, A. ecklonii clearly differs by the more numerous 2–3(–4) leaves, the much longer peduncle and the subcorymbose raceme with much longer pedicels. This species is restricted to the western mountains of the Cape Fold Belt.

Additional material studied (paratypes):— SOUTH AFRICA. Western Cape. Montagu (3320): Ladismith, 7 miles from Warmwaterberg along road to Barrydale (- DD), 1 August 1955 (in leaf), ex hort on 12 December 1955 (in flower), G. van Niekerk 567 ( BOL!) ; Ladismith (3321): Calitzdorp District, Farm NE of Town ( Besmkop ) (- DA), elev. 370 m, 29 September 2006 (in flower), P. M. Burgoyne & M. Warrington 10673 ( PRE843055 !) ; Ladismith (3321): ca. 11 km SW of Calitzdorp, Groenefontein Nature Reserve , near top of pass (- DA), elev. 408 m, 29 September 2011 (in leaf), M. Martínez-Azorín, A. P. Dold & A. Martínez-Soler MMA945 ( ABH59655 !) ; ibidem, 18 September 2005, A. P. Dold s.n. ( GRA) ; Ladismith (3321): Gamka N. R. Triangle (- DA), 9 September 2013 (in leaf), T. Rebelo s.n. (Photo on iSpot https://www.ispotnature.org/communities/southern-africa/view/observation/373024/mini-gifball) ; ibidem, 29 September 2006 (in flower), J. Kirkel s.n. ( Photo on iSpot https://www.ispotnature.org/communities/southern-africa/view/observation/316707/hyacinthaceae) ; Oudtshoorn (3322): Oudtshoorn (- CA), October 1923 (in flower), Taylor 11778 ( PRE!) ; Oudtshoorn (3322): ½ mile from Oudtshoorn (- CA), November 1932 (leaves), F. R. Long s.n. ( BOL31787 !) ; Oudtshoorn (3322): 6 km SW Dysseldorp (- CB), D. M. Cumming 11266 (Photo!). Eastern Cape. Steytlerville (3324): Joubertskraal River Pass, N of Kareedouw (- CD), D. M. Cumming 11204 (Photo at http://www. massonia.com/gallery?page=12) .

Figures

FIGURE 5. Austronea densiflora Mart.-Azorín et al. from the type locality, Grootkop Nature Reserve, NE of Oudtshoorn, Western Cape Province, South Africa, on 28 September 2011 corresponding to MMA891. A. Inflorescence; B. Flowers, frontal and dorsal views; C. Dissected flower in lateral view; D. Dissected flower showing tepals, stamens and gynoecium; E. Plants in flower; F. Bulb and leaves. Scale bars:A, E–F: 1 cm; B–D: 5 mm.

FIGURE 6. Distribution of Austronea species in southern Africa. A. densiflora Mart.-Azorín et al. (red circle), A. grandiflora Mart.- Azorín et al. (blue square), A. hispidoplicata Mart.-Azorín et al. (yellow triangle) and A. papillosa Mart.-Azorín et al. (green diamond).