Nicotiana olens M.W.Chase & Christenhusz, 2023

Bruhl, Jeremy J., Andrew, Damien D., Palsson, Ruth, Jobson, Richard W., Taseski, Guy M. & Samuel, Rosabelle, 2023, Nine new species of Australian Nicotiana (Solanaceae), Australian Systematic Botany 36 (3), pp. 167-205 : 190-194

Nicotiana olens M.W.Chase & Christenhusz , sp. nov.

( Fig. 22, 23.)

Type: New South Wales. Cocoparra National Park, Woolshed Flat Trail, Pines Picnic Grounds , 240 m, 34°4″57′ S, 146°12″58.3′ E, 10 Oct. 2017 , Chase & Christenhusz 17019 (holo: NSW; iso: CANB) .

Diagnosis

Nicotiana olens is closely related and morphologically similar to N. suaveolens , in which it was previously included. The main morphological differences are in its habit; the former has several large inflorescences produced from the base of the plant (v. a single main axis with side branches). Nicotiana olens is nearly glabrous (except for a few hairs at the base of the stems v. some hairs on nearly all parts). The flowers of N. olens (1.9–2.3 cm long) are typically shorter than those of N. suaveolens (2.2–4.2 cm long), but there is a slight overlap. Nicotiana suaveolens grows on limestone, often associated with caves, whereas N. olens is found on clay and sandstone in open sites.

Erect to arching, herbaceous, annual to short-lived perennial herbs, up to 2.0 m tall, forming a loose rosette to no rosette, numerous large leaves in the basal portion of the stems and few in the upper portions, the major branches from near the base with few side branches. Leaves with narrowly winged petioles, up to 1.5 cm wide and 7.5 cm long, blades 3.7–25.8 × 1.5–15.5 cm (including petiole), ovate-lanceolate, the apex acute in the basal leaves to acuminate in those higher up, the apical portion curled in some cases, base gradually to abruptly attenuate, uppermost leaves sessile, bract-like, margins entire, undulate, ciliate, often minutely dentate and basally bullate. Vestiture composed of long, somewhat curly, non-glandular hairs on the leaf margins and main veins and basal stems, but becoming nearly glabrous on the upper stems, ultimate stems, calyces and peduncles with short glandular hairs and a few longer, curly, non-glandular, multicellular hairs with a swollen base. Calyx 1.0–1.6 × 0.2–0.3 cm, one lobe slightly longer and one shorter than the others, the tips acuminate, clasping to reflexed, 0.5–0.6 cm longer than and surrounding the mature fruit, the calyx persistent and enlarged at maturity. Corolla tube white to pale green, 1.9–2.3 cm long (from tip of the calyx), 0.2–0.4 cm in diameter, often slightly curved downward, with a small throat cup, the upper side slightly longer than the lower, the limb white, 1.9–3.1 cm across, the lobes minutely cleft, cleft 0.2 cm deep, sinus 0.3–0.4 cm deep, lobe 0.7–1.7 cm long; stamens didynamous, 0.1–0.2 cm inside throat of the floral tube and the fifth 0.5–0.6 cm deeper in the tube, all with the filaments 0.2–0.3 cm long. Fruit a capsule splitting into four lobes, 0.8–1.2 cm long at maturity; only some plants are self-pollinating.

Distribution

Distributed in central-western New South Wales west of the Great Dividing Range and in Victoria from Melbourne west to near the Grampians ( Fig. 24), but not approaching the border of South Australia. The species might extend into southern Queensland, but no specimens have been seen from that state.

Habitat and ecology

In open to slightly shaded sites, sometimes in riverbeds and open woodlands, on clay and sandstone substrates ( Fig. 22, 23 a).

Phenology

Collected in flower from June through December.

Etymology

Named in reference to its fragrant flowers, from Latin olens , ‘scented’.

Chromosome number

This species is n = 15 with some autotetraploids recorded, whereas N. suaveolens is n = 16 ( Chase et al. 2022 b).

Notes

Specimens of Nicotiana olens have long been identified as N. suaveolens , the type of which was cultivated in France,

grown from seeds collected by Joseph Banks at Port Jackson in the 18th century. The new species is sister to this ( Fig. 1 b), but it is easily distinguished by its habit, distribution and ecology. The two species are disjunct ( Fig. 24), with the western edge of the Great Dividing Range being the transition point, N. olens to the west and N. suaveolens in the mountains of the Great Dividing Range and east-ward, often associated with limestone caves and gorges (e.g. Abercrombie, Jenolan, Wombeyan Caves; Fig. 25). It seems likely to us that N. olens as circumscribed here is a species complex; however, without doing a great deal more sampling, we cannot determine how many taxa should be recognised. A specimen identified as N. goodspeedii H.- M.Wheeler (Purdie 7721; CANB 789872) from Yathong Nature Reserve in New South Wales has flowers much too large for that species. It yielded viable seeds, which were secondarily vouchered as Chase & Christenhusz 18060 (to be deposited at NSW); these were studied by L. A. Cauz-Santos and M. W. Chase (unpubl. data) and appear to be N. olens introgressed with N. velutina . Plants grown from seeds associated with Walsh 8382 ( MEL 2396268 A) are vouchered as Chase & Christenhusz 17023 ( MEL) and included in the phylogenetic analysis ( Fig. 1 b).

Selected specimens examined

NEW SOUTH WALES. Near Mount Hope , 32.85°S, 145.87°E, 8 Nov. 1922, Patterson 18 ( NSW 48706 ) ; Yenda–Rankin Springs Stock Route, north-west of Yenda , 34°S, 146.1667°E, 30 July 1959, Burbidge 6421 ( AD 96129155 ; CANB 79280.1 ; NSW 55822 ; PERTH 3685349 ) ; 2.6 km from Goolgowie towards Hillston , 33.9167°S, 145.66679°E, Nov. 1992, Butler 1693 ( CBG 9216072.1 ) ; Whitton Stock Route Road, north of Yenda, Steamboat Creek , 200 m, 34°6′16.9″S, 146°11′52.4″E, 10 Oct. 2017, Chase & Christenhusz 17016 ( NSW, CANB) ; Whitton Stock Route Road, north of Yenda, just south of road into Woolshed Campground , 200 m, 34°6′5″S, 146°11′43.4″E, 10 Oct. 2017, Chase & Christenhusz 17017 ( NSW, CANB) ; Cocoparra NP, Woolshed Flat Trail , 40 m, 34°4′57″S, 146°13′8.8″E, 10 Oct. 2017, Chase & Christenhusz 17018 ( NSW, CANB) . VICTORIA. Little River area , Ford Motor Co. proving ground; 37.9167°S, 144.4167°E, 24 Sep. 1998, Walsh 4782 ( MEL 2051415 A) ; Mornington Peninsula National Park, Fingal walking track, 90 m, 38°28′40″S, 144°53′14″E, 11 Dec. 2015, Walsh 8382 ( MEL 2396268 A) ; Melbourne, Kew, Galatea Point , Yarrabend Park , 30 m, 37°47′57″S, 145°0′21″E, 18 Oct. 2017, Walsh 8229 ( MEL 2418211 A) .