Sansevieria embere Mollel, M.Burkart, Yinger & Sikawa, 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 : 79-86

Sansevieria embere Mollel, M.Burkart, Yinger & Sikawa sp. nov.

urn:lsid:ipni.org:names:77370779-1

Figs 1, 10–15; Table 2

Diagnosis

Sansevieria embere sp. nov. is characterised by its very long and dense, spear-like inflorescence, with 7 large sterile bracts on the peduncle, extraordinarily long-tubed flowers in partial inflorescences of only up to 3 flowers which have straight styles and anther and style exsertion of rather similar length.

Etymology

ʻEmbereʼ is a maasai word for a spear, recalling the form of the inflorescence. The place where S. embere sp. nov. was found would have been the home of Maasai.

Type material

TANZANIA • City of Arusha, Arumeru, Manyara Estate; 1448 m a.s.l.; 24 Aug. 2020; B. Yinger & R.A. Sikawa YS 0641; holotype: NHT [ 000001156 ] .

Living specimens ex typo cultivated at TSF and POTSD .

Description

Acaulescent herb, rhizomatous, vegetative height ca 1 m, 2 cataphylls and 2–4 leaves per shoot, pointing to all directions, longest leaf at intermediate position (neither outermost nor innermost) on individual shoots ( Fig. 10); fresh cataphylls purple, mottled. Rhizome subterranean but close to soil surface (ca 0–10 cm), runners to 0.2 m long, rhizome diameter ca 30–50 mm, colour of inner rhizome cortex light ochre, fresh rhizome outside view yellowish, older light brown, young cortex very thin (ca 0.2 mm), thicker when old (ca 1 mm). Leaves upright to spreading, stiff, up to 1 m long or slightly longer, 94–120(142) mm wide, central lamina 5 mm thick, flat to slightly u-shaped, lanceolate, clearly narrowed to the base but without petiole, abaxial side with insignificant central ridge, leaf base ca 50–70 mm wide and 10 mm thick, margin red-brown and whitish, often somewhat undulate, distal part narrowed to a leathery tip 2–8 mm long; adaxial surface smooth, medium to blackish green in older leaves but with bluish bloom when young, with more than 20 dark longitudinal lines from base to tip, somewhat insignificantly patterned with lighter green dots and bands in zig zag patterns, strongly glossy in cultivation but much less so in the wild ( Fig. 11); abaxial surface with punctiform elevations in a rather loose pattern, thereby finely though clearly rough to the touch, dull to silky glossy with up to 40 dark green continuous or interrupted longitudinal lines, much more clearly patterned than adaxial side; patterning of the leaves fading with age but still visible in old leaves. Inflorescence ( Fig. 12) of very conspicuous length, elongate thyrsoid, terminal on fully leaved shoot, axis 1172 mm long overall, peduncle 446 mm long, 15 mm in diameter, yellowish at the base to dark green upwards, patterned with tiny dots and lines, bearing 7 dry bracts to 281 mm long, flowering part 726 mm long, flowering inflorescence 73 mm in diameter excluding anthers and styles, dense, 1–3 flowers per partial inflorescence at the lower part, 3– 5(8)†† at the median and 1–2 at the upper part; bracts of partial inflorescences 12–21 mm long, 2–4 mm wide, herbaceous (not dry during anthesis), lanceolate, without extrafloral nectaries. Flowers on dark green, sometimes purple pedicels 5 mm long, articulated close to the receptaculum, corolla outside coloured yellowish to greenish, tube 67 mm long, lobes 31 mm long, 2 mm wide, overall flower length 98 mm, diameter of closed flower‡‡ shortly before anthesis 3.5 mm at the base, 1–1.4 mm at the narrowest point, 3 mm in the upper part; lobes strongly curling back at full anthesis ( Fig. 12B); anthers yellowish to greenish, anthers ca 4 mm long, filaments filiform, 47 mm long, styles straight, 110 mm long above ovary, 47 mm exserted from tube mouth; ovary light green to yellowish, cylindric, apex truncate. Flowers opening in the evening, wilting in the afternoon. Fruits# small to medium-sized, surface glossy when unripe, covered with numerous rather large whitish dots, slightly rugose and orange when ripe, in all stages with several but small verrucae ( Fig. 13). Seeds ( Fig. 14) elliptical, 6–7.3 mm long, 5.7–6.7 mm thick, light brown, with dull surface, hilum apical, elliptical, rather large, ca 5.3 mm diameter, brighter than the seed. Youth form (seedlings) slightly different from adult plant, leaf colouration lighter green with transversally oriented, whitish patterning ( Fig. 15).

Phenology

The flowers open in the evening as in most species of Sansevieria , but last until the following afternoon, i.e., uncommonly long.

Ecology and distribution

Sansevieria embere sp. nov. has so far been found only in a pocket of succulent vegetation in Arusha City within extensive coffee plantations ( Figs 1, 10). It is likely that this species was restricted to the area now occupied by the city and its once-vast coffee plantations, which are monocultures of coffee and Grevillea robusta A.Cunn. ex R.Br. This area is not especially arid, with long rainy seasons and occasional rains off-season. The soil is fertile and well-drained.

Taxonomic remarks

Seeds were studied from fruits collected from ca 45 individual infructescences all over the population at the type location with one fruit per shoot.

This iconic species in the subgenus Sansevieria is similar to S. raffillii N.E.Br. in overall size, leaf dimensions and posture, inflorescence size, and greenish flower colouration. It differs from this species, however, in having more leaves per shoot, darker leaf colour, leaves that are finely rough rather than smooth on the abaxial side, much longer peduncle bracts, and fewer flowers per partial inflorescence. Also, the pedicel relationships are different. Most striking, however, is the difference in flower tube length. Actually, S. embere sp. nov. is the species with the longest flower tube among all red-bordered flat-leaved species of Sansevieria with the exception of S. pedicellata la Croix , a plant from the border region of Mozambique and Zimbabwe, which is clearly different in many features ( Rulkens & Baptista 2009; la Croix 2010; Table 2 ). The next in flower size in this group, S. newtoniana T.G.Forrest occurring in Uganda and adjacent N of Tanzania ( Forrest 2014; Yinger & Sikawa 2021e), is different from S. embere in leaf colouration and stiffness as well as in inflorescence and flower features. An overview is given in Table 2 .

Several accessions similar to YS 0641 have been identified in the TSF living collection. None of these, however, has flower tubes longer than 30 mm, and several differ in other traits as well. They belong to other species, therefore, some of which possibly are undescribed yet.

Tentative threat assessment

Critically endangered: CR E.

Residual fragments of Sansevieria populations are not uncommon in and around Arusha, but there does not seem to be another one of this species. At least, we could not find any during numerous excursions. It appears that the survival of this particular colony is intentional although no one lives nearby.

There is only this single population known, with very limited spatial extent (less than 10 m × 100 m) and limited although conspicuous size, and without any legal conservation status, on privately-owned but publicly accessible land. We suppose that the probability of this single population to become extinguished is> 50% in 3 generations as it occurs within the Arusha City limits (IUCN criterion E), classifying it as CR according to our data.