Prostanthera faucicola Palsson & I.Telford, 2025

Prostanthera faucicola Palsson & I.Telford , sp. nov.

( Fig. 10 View Fig , 11 View Fig .)

Type: New South Wales. Northern Tablelands: Paradise Rocks area , lookout S of trig point, Oxley Wild River National Park , 10 Nov. 2015, M. F . Duretto 4027 & T. L . Collins (holo: NSW 858436 About NSW *; iso: CANB!, NE 107073 !) .

Prostranthera faucicola is morphologically similar to P. dyarubbin and P. milleri but differs in the floral prophylls usually being asymmetrical and wider; short anther appendages in P. faucicola with 3–6 conical hairs v. 15–35 in P. dyarubbin and 6–12 in P. milleri ( Table 1).

Shrub to 2 m tall. Branchlets quadrangular, with scattered glandular trichomes and densely distributed antrorse non-glandular hairs in rows on the leaf decurrencies, non-glandular hairs ~ 0.15 mm long, white. Juvenile leaves not seen, toothed leaves not noted on mature plants. Leaves discolourous, darker above; petiole 2.5–8.0 mm long; lamina ovate to lanceolate, 12–27 mm long (longer leaves appear to be on a water shoot), 5–10 mm wide (wider leaves appear to be on a water shoot), length to width ratio 2.1–3.1, length of maximum width from base to total lamina length ratio 0.3–0.5, base cuneate, sometimes attenuate, margin entire, apex usually obtuse, mostly without non-glandular hairs except for occasional non-glandular hairs on prominent midrib on abaxial surface, in depressed midrib on adaxial surface (depressed for ~2/3 length with sparse antrorse non-glandular hairs to 0.15 mm long) and for up to the proximal 2/3 of margin (antrorse simple non-glandular hairs up to 0.15 mm long); abaxial surface densely glandular (60–100 mm −2), secondary veins sometimes visible; adaxial surface moderately to densely glandular (25–70 mm −2). Inflorescences compact thryses to ~ 1.5 cm long with dichasia usually reduced to single flowers. Floral bracts caducous, broadly scutiform and concave, apex rounded, vary in shape along axis of inflorescence, central floral bracts 2.75–4.0 mm long, 2.75–3.25 mm wide, size depends on position in inflorescence and maturity; abaxially scattered non-glandular hairs and scattered to densely glandular, glandular trichomes and non-glandular hairs becoming sparse towards distal margin, non-glandular hairs to 0.15 mm long; adaxially without non-glandular hairs; margin ciliate, non-glandular hairs to 0.05 mm long on distal margin, up to 0.2 mm elsewhere on margin. Pedicel 1.5–1.75 mm long. Floral prophylls persistent, opposite, usually inserted at base of calyx, narrowly elliptic, 2.0– 3.5 mm long, 0.5–1.0 mm wide, length to width ratio 3–5, not always symmetrical; abaxial surface non-glandular hairy with non-glandular hairs to 0.2 mm long, moderately densely glandular; adaxial surface without non-glandular hairs; margin ciliate to densely ciliate (non-glandular hairs up to 0.25 mm), apex ±without non-glandular hairs. Calyx colour not recorded, bilobed, both lobes recurved, outer surface moderately to densely glandular, scattered non-glandular hairs particularly on the tube, non-glandular hairs up to 0.1 mm long; inner calyx tube and inner abaxial calyx lobe without non-glandular hairs; inner adaxial calyx lobe moderately to densely hairy, non-glandular hairs up to 0.05 mm long; margin ciliate, white non-glandular hairs, 0.02–0.05 mm long; tube ~ 1.5 mm long, sometimes ridged in dried specimens; abaxial lobe elliptic, ~ 2.4 mm long, ~ 2.2–2.7 mm wide at base, apex rounded; adaxial lobe oblate, ~ 1.2 mm long, 1.9–2.5 mm wide at base, apex rounded; adaxial lobe length to abaxial lobe length ratio ~0.5. Corolla colour not recorded; adaxial corolla tube length ~ 2.5 mm long; outer surface moderately hairy beyond calyx, ±antrorse non-glandular hairs up to 0.1 mm long, moderately densely glandular on lobes; corolla margin, particularly on adaxial lobes, with white non-glandular hairs 0.02–0.05 mm long; inner surface tube and abaxial lobe without non-glandular hairs, adaxial lobe hairy to densely hairy, non-glandular hairs to 0.05 mm long; abaxial median lobe broadly elliptic, 1.6–1.9 mm long, 1.2–1.8 mm wide, 1.2–1.5 mm wide below distal lobing when present, length to width ratio 1.0–1.4; apex rounded; lateral lobes usually shallowly triangular to deltate, 1.5–2.0 mm long, 1.5–2.2 mm wide, length to width ratio 0.8–1.3; apex rounded; adaxial median lobe-pair depressed ovate, sometimes distal lobing, ~1.0 mm long, 1.2–1.8 mm wide, length to width ratio 0.5–0.8. Stamens inserted 0.5–0.8 mm above corolla base; filaments 0.6–1.0 mm long; anther locules ~ 0.75 mm long; anthers, colour not seen; connective extended to form 1 or 2 basal appendages (one appendage usually shorter than the other), extending beyond base of anther and terminating in 3–6 translucent conical hairs; length beyond the anther of appendage including hairs ~ 0.4 mm, hairs to 0.05 mm. Pistil ~6.0 mm long; ovary cylindrical obovoid, 0.6–0.8 mm long, diameter at base 0.5–0.6 mm, lobes 0.3–0.5 mm long; style ~5.0 mm long; stigmatic lobes ~ 0.6 mm long. Fruiting calyx slightly accrescent. Mericarps, mature mericarps not seen.

Phytochemistry

Has not been assessed.

Distribution

Prostanthera faucicola occurs in the Macleay Gorges subregion of the New South Wales North Coast bioregion where the species is known from two populations in Oxley Wild Rivers National Park, east of Walcha, New South Wales ( Fig. 6 View Fig ).

Habitat

The species grows in shallow skeletal soil on rock outcrops and cliff tops of gorge rims at altitudes of 980–1055 m.

Vegetation in which the species occurs is recorded as Eucalyptus woodland and heath with Leptospermum variable and Leionema beckleri .

Phenology

Flowers recorded in November, fruiting mid-November to early December.

Conservation status

On the basis of three specimens known from two collection sites of unknown population size, we suggest that a ‘Data Deficient’ status is appropriate under the International Union for Conservation of Nature (2019).

Etymology

The specific epithet is from the Latin fauces (throat or gorge) and -cola (dwelling) referring to the habitat of the species.

Notes

The informal tag name Prostanthera sp. Oxley Wild Rivers National Park (J.B. Williams s.n. NE 91044) has been used at NE for curatorial purposes and this study.

Specimens examined

NEW SOUTH WALES: Northern Tablelands: Paradise Rocks, ~ 50 km E of Walcha , 3 Dec. 1978, J. B . Williams s.n. ( NE 91044 !); Oxley Wild Rivers National Park (2009 addition), on southern side of large rocky outcrop 1.6 km NNW of ‘ Garibaldi’ homestead, 21 Dec. 2008, L. M . Copeland 4355 ( NE!) .