Sansevieria chlorantha M.Burkart, Kavula, Sikawa & Yinger, 2025

Burkart, Michael, Kavula, Kened Alfred, Constantine, Immaculate Kileo, Mollel, Neduvoto Piniel, Piniely, Luciana Naftal, Sikawa, Robert Augustino & Yinger, Barry R., 2025, Sansevieria bangalalana sp. nov. (Asparagales, Asparagaceae), close to extinction in the wild, and five other narrowly endemic and threatened species of Sansevieria from Tanzania previously unknown to science, European Journal of Taxonomy 1026, pp. 65-106 : 74-79

Sansevieria chlorantha M.Burkart, Kavula, Sikawa & Yinger sp. nov.

urn:lsid:ipni.org:names:77370778-1

Figs 1, 7–9; Table 1

Diagnosis

Sansevieria chlorantha sp. nov. is characterised by its short but rather thick brownish rhizomes, its numerous, long, narrow, rather thick and clearly patterned leaves, its long inflorescence with medium-sized, greenish flowers, the colour extending to the style and filaments, its conspicuous, long-living bracts of the partial inflorescences, its styles that are distinctly longer than the filaments, and its grass-like flower odour. The greenish colouration of filaments and style, or parts of them, is very unusual in the genus.

Etymology

Sansevieria chlorantha sp. nov. was named for the largely green flower colour, including parts of the filaments and style.

Type material

TANZANIA • Kilimanjaro Region, remnant of natural vegetation within a village; 810 m a.s.l.; 17 Mar. 2020; B. Yinger & R.A. Sikawa YS 0350; holotype: NHT [ 000001155 ] .

Living specimens ex typo cultivated at TSF and POTSD .

Description

Acaulescent herb, rhizomatous, stemless, vegetative height around 1 m, ca 6 leaves per shoot, longest leaf at intermediate position, forming dense stands ( Fig. 7A). Rhizome to 150 mm long, rhizome diameter 35–50 mm, inner rhizome cortex brownish. Leaves dispersed in all directions, upright to spreading, very stiff, up to 1 m long or a little bit longer, to 62 mm wide, strap-like, without petiole but with a median ridge on the abaxial side, lamina u-shaped to somewhat v-shaped and thickened to 42 mm in central part††, slightly rough on the adaxial and clearly but finely rough on the abaxial surface, dull dark green, whitish dotted and transversely banded, darker colour covering ca 60–70% of leaf adaxial surface but only ca 50% of abaxial surface, pattern not fading with leaf age, margin red-brown and whitish, with ca 8 dark longitudinal lines from base to tip adaxially and ca 15 abaxially, leaf base to 63 mm wide, awn-like tip to 74 mm long, leathery. Inflorescence ( Fig. 7) unbranched elongate, central on fully leaved shoot, up to 1.35 m long, peduncle to 0.5 m long, green, 14 mm in diameter between the two lowermost bracts, patterned with tiny dots and lines, with three peduncle bracts to 175 mm long and two hypsophylls (intermediate basal leaflets bigger than the bracts but much smaller than the leaves) below them, bracts light green with purple dots; flowering part 0.85 m long, flowers arranged densely to lax, subverticillately, 6 (5–7) flowers per partial inflorescence but fewer in the upper part, lower bracts of partial inflorescences to 55 mm long and 14 mm wide, central and upper ca 13–17 mm long and 4–5 mm wide, triangular to lanceolate, not dry at anthesis. Flowers medium-sized, on articulate pedicels 9–12(14) mm long, basal part 6–9 mm, distal part‡‡ ca 3 mm, light green, corolla outside coloured light green as well, without longitudinal lines, wilting flowers not changing colour substantially, basal diameter ca 3 mm but only ca 2 mm on narrowest part, tubes ca 25 mm long, lobes ca 18 mm long and ca 2 mm wide, curling back at anthesis to 360°, filaments greenish, thread-like (not substantially flattened or widened), ca 16 mm long, anthers closed ca 4 mm long, opened ca 3 mm long, yellow green, style white to greenish, straight, ca 54 mm long above ovary, ca 31 mm exserted from flower throat (i.e., greatly exceeding the filaments), stigma ca 1 mm wide, translucent, ovary ovoid, yellow green; flowers open from evening to early morning; flower odour: fresh grass. Fruits# glossy and slightly warty when unripe, orange and almost smooth when ripe ( Fig. 8A). Seeds# globular to elliptical, 5.5–7.3 mm long, 4.4–5.5(6.7) mm thick, yellowish or light brown (colour dimorphic), hilum lateral, large, circular to elliptical, diameter 3.5–5.3 mm, brighter than the light brown seed surface ( Fig. 8B–C).

Ecology and distribution

Sansevieria chlorantha sp. nov. was found only once in a village occupying a strip of remaining natural vegetation on gently sloping land. Downslope, where there are soils suitable for field crops, the land is now entirely converted to agriculture. Until recently, these plants were growing in the shade of a strip of native trees remaining before the village expanded. Nearly all of these trees were removed when the road was widened. Upslope are extensive populations of S. volkensii . This is a very arid area with stiff infertile soil in the Kilimanjaro Province, North Pare Mountains region ( Fig. 1).

Taxonomic remarks

Sansevieria chlorantha sp. nov. (subgenus Sansevieria ) has similarities to S. enchiridiofolia R.H.Webb & L.E.Newton which also seems to have conspicuous, long-lasting, greenish bracts of partial inflorescences (see Webb & Newton 2019: fig. 7) and rather thick, narrow leaves of similar, dark green colouration and patterning. Sansevieria enchiridiofolia , however, is clearly different due to its mostly single-leaved shoots, sweetly-scented flowers that are white instead of greenish, and longer styles. It is also a rare species, occurring more to the north in Tanzania, north of Arusha, and possibly also in adjacent Kenya ( Webb & Newton 2019; MB pers. obs.). Also, S. lunatifolia L.E.Newton from S Kenya has similarities in the leaf dimensions and cross-section ( Newton 2015). However, it has rougher and thinner leaves and the flower traits are different including scent, colouration and filament length. This species is also rare. The more frequent S. rugosifolia R.H.Webb & L.E.Newton has much shorter but wider leaves of different colouration and further differences in inflorescence and flower features. Table 1 gives an overview.

Sansevieria chlorantha sp. nov. was tentatively named S. viridiflora in Yinger & Sikawa (2023c).

Tentative threat assessment

Critically endangered: CR B2ab(v); C1; E.

We only know one certain population of S. chlorantha sp. nov. which is at the type location. In March 2020, there were more than 200 shoots, but the population in September 2023 was only about 100 shoots, i.e., a reduction by 50% in less than 4 years and one generation ( Fig. 9). Since then, it has further declined (last visit in January, 2025). According to IUCN criteria B2 (AOO < 10 km ², only 1 location known and continuing decline observed in number of mature individuals) and C1 (population decline of more than 25% in 1 generation), we rate this species as Critically Endangered (CR) according to our data. As the location is in an intensely developed area where land is at a premium for housing and small businesses, extinction in the wild might happen soon (criterion E, probability of extinction in the wild>50% within 3 generations).