Nicotiana erytheia M.W.Chase & Christenh., 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 : 200-204

Nicotiana erytheia M.W.Chase & Christenh. , sp. nov.

( Fig. 30, 31.)

Type: Western Australia. North West Coastal Highway (1), ~ 8 km north of entrance to Eurardy Station , on both sides of road, 165 m, 27°30′20″S, 114°43′9″E, 21 Sep. 2019, Chase & Christenhusz 19126 (holo: PERTH; iso: CANB) .

Diagnosis

Nicotiana erytheia is closely related to N. salina and an undescribed species we have preliminarily been calling N.

sp. nov. Eagle Bluff ( Fig. 1 a). These three species are similar in their relatively short habit with many branches from the base of the plant, but the calyx in N. erytheia does not reflex at maturity and its leaves are narrower for their length than those of N. salina (1:3 v. 1:2). The ecology and ranges of these three species distinguish them most readily (see below).

Erect, herbaceous, annual herbs, up to 80 cm tall, forming a loose rosette with many leaves on the stems, producing several thin, wiry stems simultaneously. Leaves with petioles up to 3.0 cm long with a wing up to 1.8 cm wide, blades ovate-lanceolate, 3.8–22.5 × 1.6–9.2 cm including petiole, becoming sessile on the stems, gently attenuate, the apex obtuse to acute, margins entire, ciliate, undulating. Vestiture on stem bases and major leaf veins composed of dense long, hairs that are often slightly twisted and bearing a minute gland, leaf surface densely covered with mostly shorter, gland-tipped hairs, stems progressively less woolly and more predominantly covered with shorter hairs with a prominent ellipsoidal gland and a few longer, sometimes slightly bent with a small peduncle with some longer hairs, but more commonly moderate length and shorter hairs, all with a gland, calyx with short hairs, all gland-tipped, corolla tube exterior densely covered with short, straight to slightly recurving, small gland-tipped hairs. Inflorescence bracts sessile, linear, ~0.5–1.0 cm long, the apex acuminate. Calyx 0.9–1.4 × 0.1–0.2 cm, one lobe slightly longer and one shorter, the tips acuminate, appressed to ovary to slightly flaring, 0.3–0.4 cm longer than and surrounding the fruit, slightly wider, persistent and clasping to slightly reflexed in the fruit. Corolla tube 0.3–0.8 cm long (from end of the calyx), 0.15–0.20 cm in diameter, with a slight throat cup with a pinched apex, the limb 1.1–1.5 cm across, the lobes minutely cleft, sinus 0.4 cm, deep, four stamens in stamen cup, 0.15–0.20 cm deeper than tube entrance, the fifth 0.3–0.4 cm deeper in tube. Fruit a capsule, 0.7–1.0 cm long, splitting in four lobes.

Distribution

Restricted to Western Australia in the narrow transition zone from the more humid areas along the coast to the dry interior from just south of the Wooramel River to the Murchison River along the North West Coastal Highway ( Fig. 19).

Habitat and ecology

In shaded sites under mulga and occasionally in the open.

Phenology

Flowering August to November.

Etymology

Named for Erytheia, one of the Hesperid nymphs of Greek mythology, who were the ‘daughters of the evening’ or ‘nymphs of the west’, a reference to the occurrence of this species in the far west of Western Australia. The species epithet is a noun in apposition.

Chromosome number

Unknown.

Notes

Specimens of Nicotiana erytheia are similar to those of N. hesperis and are likely to have been confused with the latter. Both have small flowers, but they are not closely related, although both are members of the N. occidentalis clade and bear the characteristic short, gland-tipped hairs covering all parts.

Chase and Christenhusz (2021 a) described N. insecticida M.W.Chase & Christenh. and noted that its geographical range was especially large, stretching from the western coast of the Pilbara Craton in Western Australia to the central Northern Territory. There are probably only a few species of N. section Suaveolentes (e.g. N. heterantha Symon & Kenneally ) with such a large range. Given their generally highly inbred nature ( Cauz-Santos et al. 2022), maintenance of genetic cohesion over such large distances is unlikely, and when we added many more accessions to the matrix, we saw that there is a clear geographic structure in N. insecticida that is consistent with approximately six genetically distinct species ( L. A. Cauz-Santos and M. W. Chase, unpubl. data), among them material collected at the type locality of N. hesperis (Chase & Christenhusz 68258, PERTH; Fig. 1 a).

In September 1959, Nancy Burbidge visited Rocky Pool, ~ 40 km west of Carnavon in Western Australia and collected what she designated as the type specimen of N. hesperis (Burbidge 6494 A!, CANB 236744). In 2015, we visited this location and found several species of Nicotiana growing there, one of which was similar to the Burbidge’s specimen of N. hesperis . This accession (Chase & Christenhusz 68258, PERTH; Fig. 1 a) is clearly distantly related to those that Chase and Christenhusz (2021 c) ascribed to N. hesperis from sites further south along the North West Coastal Highway. Furthermore, this accession appears to be highly introgressed with another species of the N. insecticida species complex, and if this is the case then the type material of N. hesperis collected by Burbidge in 1959 may also have been a hybrid or introgressed individual. In 2023, M. W. Chase, M. J. M. Christenhusz and L. A. Cauz-Santos made a return trip to Rocky Pool and collected another plant similar to the type specimen of N. hesperis , which we plan to examine genetically. We also travelled further east in the Gascoyne River basin, as far east as the Great Northern Highway, and we collected several other small-flowered accessions that are like those at Rocky Pool. We think these additional accessions also correspond to N. hesperis , which would make this a widespread species, but confined to this river basin further north (120 km) of the area where N. erytheia occurs ( Fig. 29), starting at the Wooramel River. We have found no material of N. erytheia further inland than the transition zone along the coastal plain and the inland scrub between the Murchison and Wooramel rivers.

A study of the species limits in the larger N. occidentalis clade is underway ( L. A. Cauz-Santos and M. W. Chase, unpubl. data), and these more detailed analyses will include greater sampling of accessions. In this paper, we have shown that the accessions of Chase and Christenhusz (2021 c) included in N. hesperis , except for that from the Rocky Pool type locality, are members of what we describe here as N. erytheia .

The three closely related species of the N. occidentalis complex, including N. erytheia ( Fig. 1 a), are similar morphologically and most readily distinguished by their ecologies and distribution. These three are Nicotiana sp. nov. Eagle Bluff, which is found in exposed sites in the Tamala eolianite limestone heathlands on the offshore Abrolhos Islands and the coast from just north of Geraldton north to Lake Macleod, N. salina , associated with salt lakes and rivers in the interior from Lake Weelhamby south to Jibberding and east to the Goldfields, where it grows near the salt vegetation but not directly in it, and N. erytheia , found under mulga and other acacias in a narrow, nearcoastal range from the Murchison River just to the south of the Wooramel River. Specimens of N. erytheia collected near the Shark Bay Road (Chase & Christenhusz 68273, 68274) are much laxer in habit, with primarily cleistogamous flowers (at least in cultivation).

Specimens examined

WESTERN AUSTRALIA. Hamelin Pool Road off Shark Bay Road, 10 m, 26°24′11″S, 114°9′59″E, 22 Aug. 2015, Chase & Christenhusz 68273 ( PERTH) ; Hamelin Pool Road off Shark Bay Road, 10 m, 26°24′11″S, 114°9′59″E, 22 Aug. 2015, Chase & Christenhusz 68274 ( PERTH) ; North West Coastal Highway, 2 km south of Billabong Roadhouse , 150 m, 26°50′37″S, 114°37′29″E, 22 Aug. 2015, Chase & Christenhusz 68276 ( PERTH) ; North West Coastal Highway, south of Nerren Nerren , 190 m, 27°8′46″S, 114°37′11″E, 22 Aug. 2015, Chase & Christenhusz 68277 ( PERTH) ; North West Coastal Highway, bridge over the Murchison River , south-eastern side of bridge, 180 m, 27°49′40″S, 114°41′19″E, 22 Aug. 2015, Chase & Christenhusz 68278 ( PERTH) ; North West Coastal Highway, opposite road to Eurardy Station , verge on eastern side of road, 245 m, 27°34′31″S, 114°42′3″E, 19 Sep. 2019, Chase & Christenhusz 19117 ( PERTH) ; ~ 0.6 km south of turnoff to Coburn Station , verge on eastern side of road, 150 m, 26°42′20″S, 114°34′24″E, 20 Sep. 2019, Chase & Christenhusz 19123 ( PERTH) ; ~ 1.9 km north of Galatea Bridge on North West Coastal Highway , eastern side of road, 200 m, 27°48′39″S, 114°41′25″E, 21 Sep. 2019, Chase & Christenhusz 19127 ( PERTH) .