Lindernia sallyae Eb.Fisch., Vollesen & I.Darbysh., 2023

Fischer, Eberhard, Vollesen, Kaj B. & Darbyshire, Iain, 2023, A new species of Lindernia (Linderniaceae) from Tanzania, Phytotaxa 579 (2), pp. 132-138 : 132-133

Lindernia sallyae Eb.Fisch., Vollesen & I.Darbysh. sp. nov. ( Fig. 1 )

Type :— TANZANIA. T4 Mpanda District, 3 km S of Uzondo Camp, 5°31’S 30°32’E, 1600 m, 11 March 2009, S.Bidgood, G.Leliyo & K.Vollesen 8092 (holotype K!, isotypes DAR!, NHT!) .

Lindernia sallyae differs from Lindernia linearifolia and L. monroi in the lack of basal rosulate leaves, the calyx with short tube of 1–2 mm and the acute lobes of 1 mm length, the yellow corolla with purple marks and veins, the larger lower lip of the corolla of 8 × 5–6 mm, the longer abaxial stamens of 5–6 mm with acute anthers, and the glabrous adaxial stamens of 2–3 mm length.

Erect or ascending perennial herbs 9–12 cm tall, rooting in lower part of the slightly quadrangular stem, that is c. 1 mm in diameter. Leaves opposite, well spaced by internodes of 10–12 mm, glabrous, subulate-terete and subsucculent, 10–15 × 0.8–1 mm, apex obtuse, tinged with purple. Inflorescences frondose, with leaf-like bracts, flowers axillary and solitary, each node of bracts with just one fertile bract bearing a flower; flowers ebracteolate; pedicels 5−16 mm long or rarely shorter in flower. Calyx green with purple lobes or purple extending to near the base, tube 1−2 mm long, 5-lobed with acute lobes 1 mm long, purple, with minute hairs at margin. Corolla yellow with purple marks and veins, bilabiate; tube held erect, cylindrical, 2−3 mm long, c. 1.5 mm in diameter; upper lip hooded, triangular-attenuate from broad base, 3 mm wide at base, narrowed near apex, slightly emarginated, lateral margins with minute hairs; lower lip with three rounded lobes 8 mm long and 5–6 mm wide, with irregular subcrenulate margin, palate minutely puberulous centrally and extending into throat. Stamens four, adaxial stamens attached at base of upper lip, filaments 2−3 mm long, glabrous, convergent, the divergent anther thecae forming a cross-shape, thecae 1.5−1.8 mm long, acute at apex; abaxial stamens attached on palate of lower lip, geniculate with a swollen yellow-puberulous boss (knee-like appendage) 1.5 mm long, and a recurved filament up to 5−6 mm long when flattened, apex with acute anthers up to 1.5 mm long. Pistil glabrous; ovary oblong, 1.5–2 mm long; style slender, 6.5 mm long; stigma of two broad membranous lobes, ± 1.5 mm in diameter. Mature fruit unknown. Seeds not alveolated, immature, with shallow longitudinal ribs.

Distribution:— Tanzania (Flora of Tropical East Africa region T4), only known from the type locality.

Etymology:—Named after Sally Bidgood (13 April 1948 – 18 March 2018) who collected the type specimen and who worked for many years on Scrophulariaceae and related families at Kew (see Polhill & Polhill 2015; Friis 2018).

Habitat and Ecology:—Large areas of short seasonally inundated Loudetia grassland on shallow sandy-peaty soil over sandstone rocks at 1600 m a.s.l. The species is probably poikilohydric.

Conservation status:— Lindernia sallyae has at present only been observed at the type locality. Here, it was found in seasonally inundated grassland over shallow rocks and only visible in the rainy season, and there is no observation of an actual threat at this locality. The Uzondo Plateau is bissected by the main north-south road in Western Tanzania, between Uvinza and Mpanda, but this route is not busy at present and the locality remains fairly remote. Additionally, this region is clearly under-collected. Thus the species could easily be overlooked and may well occur at other sites in the Mpanda area and beyond. In the light of the limited distribution, population and threat data on this species, it is provisionally assessed as DD (Data Deficient), according to the IUCN (2022) categories and criteria.

Figures

FIGURE 1. Lindernia sallyae. A−B: habit; C & D: detail of inflorescence; E: flower; F & G: abaxial stamens; H & I: adaxial stamens; J: calyx with style and stigma; K: ovary with style and stigma. Drawn by E. Fischer.