Pytinicarpa kaalaensis Lannuzel, Gâteblé & M.Pignal, 2022

Lannuzel, Guillaume, Pignal, Marc & Gâteblé, Gildas, 2022, Pytinicarpa (Asteraceae, Astereae) in New Caledonia, Phytotaxa 574 (2), pp. 121-136 : 126-128

Pytinicarpa kaalaensis Lannuzel, Gâteblé & M.Pignal , sp. nov. ( Figs. 4 , 5 )

Diagnosis:— Pytinicarpa kaalaensis affinis P. sarasinii anguste oblongis foliis et corollae ligulatae piloso tubo, sed foliis brevioribus et corollae tubo densiore piloso atque Lagenophorinarum neocaledonicarum aliis omnibus caule (vs. rosulam) praecipue differt.

Type :— NEW CALEDONIA. North Prov. : Mont Kaala (Sommet Nord), 1080 m, 17 April 1977, H. S.MacKee 33040 (Holotype: P barcode P03276835 !; isotypes: B, BISH barcode BPBM751901 , CHR, G, K, MO, NOU barcode NOU071919 !, NSW, US barcode US 2592926 image!) .

Perennial rhizomatous herbs; roots fleshy; young plants with one erect stem, older ones with 1 to 5 stems, procumbent then erect in the leafy portion. Stems up to 25 cm, lanate; leaves inserted along the stem, older at the base, often withered. Leaves 10–30, narrowly oblong, 2–5 cm long × 0.4–0.8 cm wide (5–6.5 × longer than wide), sessile; lamina apex rounded, sometimes with a terminal tooth; margins entire or with 1–2 teeth per side, each tooth ca. 1 mm long; upper leaf surface green, lanate at base with trichomes ca. 1.5 mm long, densely hairy towards apex; lower leaf surface pale green lanate at base with trichomes ca. 1.5 mm long, densely hairy towards apex; leaf margins densely hairy, with trichomes ca. 1 mm long; veins usually obscure on dried material on both surfaces. Scapes 1–3 per stem, subterminal or sometimes at leaf axil, 2.7–25 cm long, 1–1.5 mm diameter; bracts 2–4, ca. 2–4 × ca. 0.8 mm with trichomes 0.6–0.9 mm long, 15–20 trichomes (1 mm long) per mm² at mid-point of scape, 15–20 trichomes (0.5 mm long) per mm² towards apex. Capitula 3.7–4.5 mm long, 3.8–5.7 mm diameter; phyllaries ca. 26 in 3 rows, lanceolate, oblong or obovate, apex obtuse to acute, glabrous or hairy, margin laciniate on distal half, outer phyllaries 1.6–2.3 × 0.9–1 mm, inner phyllaries 2.1–3.9 × 0.8–1 mm. Receptacle convex, 2–3 mm diameter and 0.8–1 mm high. Ray florets female, 30–40 in 1–2 rows; tube, ca. 0.6 mm long, ca. 0.5 mm wide, greenish, densely covered with trichomes, each ca. 1 mm; ligules ca. 4.5 mm × ca. 0.9 mm, glabrous, with longitudinal veins obscure, white, creamy or purple with age, apex acute to obtuse or bidentate; style branches ca. 0.4 mm long, ovary 1.8 × 0.5 mm. Disc florets male ca. 45, tubular, 3–3.3 mm long, outer surface with sparse trichomes ca. 1 mm long at base; corolla lobes 5, deltate, 0.2–0.3 × 0.8–1 mm; stamens 5, anthers ca. 1 mm long; style branches ca. 1.2 mm long; sterile ovary 1.3–1.8 mm long; corolla light yellow, pappus scales absent. Cypselae oval in cross section, lacking beak, oblanceolate, 2.6–3 × 0.6–1 mm, uniformly brown at maturity; surfaces with 1–2 longitudinal ribs on each side.

Distribution and habitat:—Restricted to Mount Kaala ultramafic massif, at relatively high elevation, from 600 m to the summit at 1080 m. It grows in open “maquis minier” within blocks of peridotites ( Fig. 4A ). Its habitat and putative distribution within the massif have recently been modelled by Lannuzel et al. (2021b) using refined SDMs (species distribution models) methods.

Phenology:—Based on ad hoc surveys (Lannuzel et al., unpublished) and herbarium specimens, the species appears to flower almost throughout the year with a gap in February and March. In cultivation, it seems to be able to flower throughout the year as well, but too few specimens were surveyed to make any definite conclusion.

Etymology:—The specific epithet refers to Mount Kaala, the only known location of the species.

Conservation status:—On the Kaala massif, this new species is highly threatened by open nickel mining activities that have already impacted some populations and are likely to destroy the others. As it has a very narrow endemic distribution with an EOO of 6 km ² and an AOO of 16 km ², the species meets the Critically Endangered category under criterion B as CR B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v), following IUCN (2019) guidelines.

Notes:— Pytinicarpa kaalaensis differs from all other Lagenophorinae species of New Caledonia by its caulescent habit. It resembles P. sarasinii (Däniker) G.L.Nesom with leaves narrowly oblong and hairy ray florets corolla tube, but has shorter leaves and more densely hairy corolla tube. One specimen of this taxon (Green 1817) was identified by Nesom (1994a) as P. sarasinii , but subsequent material supports the distinction of a new species restricted to Mt. Kaala.

The label of the isotype specimen in NOU (NOU071919) incorrectly mentions that the plant comes from the garden of ORSTOM (now IRD). Instead, this specimen was collected, like the others, on the north summit of Mount Kaala, 1080 m elev., on 17 April 1977 as written in MacKee’s gazetteer held at NOU. The error comes from a handwritten note in this gazetteer stating “planté dans le jardin du centre”. This manuscript note from Jean-Marie Veillon (confirmed by J.-M. Veillon himself in May 2021) was added to the gazetteer to add the information that living plants of this MacKee collection have also been planted in the garden, a common practice at ORSTOM during this period ( Gâteblé 2015: 27). The staff in NOU who made the label then mixed the original note from MacKee with the one from Veillon. Despite this error on the label, the NOU specimen should be considered as an isotype. Other isotypes are cited according to the duplicates listed on the holotype’s label at P (P03276835), but most of them were not retrieved in herbaria online databases.

Specimens examined:— NEW CALEDONIA. North Prov. : Mont Kaala, 600 m, 29 June 2010, Barrabé, Nigote, Merlot & Broucke 995 ( NOU053782 !) ; Sommet du Kaala, 1050 m, 20°36’45.45”S, 164°23’22.32”E, 27 April 2016, Gâteblé 763 ( NOU105458 !) ; Top of Mont Kaala (about 15 km SE of Koumac), 1000 m, 9 December 1963, Green 1817 ( A00283448 ) ; Mont Kaala , Pic de Pandop, 800 m, 6 July 1992, Jaffré 3163 ( NOU071921 !) ; Mont Kaala , sommet proche de l’antenne, 1065 m, 20°36’44”S, 164°23’22”E, 10 January 2018, Lannuzel & Balmot 134-1 ( NOU088999 !) ; Mont Kaala , sommet proche de l’antenne, 1065 m, 20°36’44”S, 164°23’22”E, 10 January 2018, Lannuzel & Balmot 134-2 ( NOU089000 !) ; Mont Kaala , sommet proche de l’antenne, 1065 m, 20°36’44”S, 164°23’22”E, 10 January 2018, Lannuzel & Balmot 134-3 ( NOU089001 !) ; Mont Kaala , pente nord, 800 m, 17 May 1981, MacKee 39081 ( NOU071920 !, P03276837 !) ; Mont Kaala , sommet nord, 1050 m, 17 May 1981, MacKee 39088 ( P03276831 !) ; Sommet du Mont Kaala , 21 June 1966, Nothis 192 ( NOU054756 !) ; Mt Kaala , 1000 m, 16 June 1982, Suprin 1990 ( NOU054755 !, P04234040 !, P04234041 !) .

Figures

FIGURE 4. Pytinicarpa kaalaensis Lannuzel, Gâteblé & M.Pignal, sp. nov.A. Habit; B. Capitulum; C. Capitulum in longitudinal section; D. Disc floret; E. Ray floret; F. Cypsela. A–F from Lannuzel 134. Photos from G. Lannuzel. Scale bars: 1 mm.

FIGURE 5. Distribution of Pytinicarpa kaalaensis Lannuzel, Gâteblé & M.Pignal, sp. nov. with a focus on Mount Kaala massif (A). Grey shaded areas represent ultramafic outcrops.