Blepharis eilensis Baldesi & Vollesen, 2022

Baldesi, Giacomo & Vollesen, Kaj, 2022, A striking new species of Blepharis (Acanthaceae) from north-eastern Somalia, Phytotaxa 539 (1), pp. 62-68 : 63-65

Blepharis eilensis Baldesi & Vollesen , sp. nov. ( Figs. 1–3 )

Typus: — SOMALIA, Nogal (Nugaal) region, Eyl district, E of Eil ( Eyl ), 24 Nov. 1970, R. Bavazzano & J. Lavranos s.n. (holotypus FT [ FT0008061 !])

Diagnosis: — Blepharis eilensis sp. nov. affinis B. forgiarinii J.-P.Lebrun & Stork sed apice foliorum plerumque tridentato, bracteis sterilibus acriter spinescentibus, spica (1–)2–4-flora et indumento bractearum stipitato-glanduloso distincta. Inter species sectionis Acanthodii etiam sepalis dorsali ventralique subaequantibus, limbo corollae trilobato et pare anteriori staminium non appendiculati insignis.

Description: — Dwarf shrub, 5–10 cm tall, very spiny, cushion shaped and intricately branched; young branches greyish, densely pubescent with whitish hairs, densest at nodes, older stems with brown corky bark. Leaves stiff and leathery, mostly crowded at the end of branches, covered with appressed forwardly directed bulbous-based hairs; lamina elliptic-lanceolate to oblanceolate, spathulate or narrowly obovate, 5–20 x 1–5 mm, terminating in a tridentate apex with each tooth ending in a spiny mucro, 1–3 mm long, or occasionally with a single apical mucro, leaf base cuneate or attenuate into a petiole-like base up to 2 mm long. Spikes ca. 2 cm long (excl. bracts), (1–)2–4-flowered, subsessile. Sterile bracts 2–3 pairs, modified into rigid spines 15–25 mm long, upper pair with reduced lamina, lower without, sparsely glandular pubescent and ciliate, greenish-white, ending in a hard trifurcate spine of which the central spine 1.0– 1.5 cm long; the lateral spines 3–7 mm long, occasionally the lowermost pair ending in a single spine. Fertile bracts greenish with whitish veins, 3-veined from the base, ciliate and minutely glandular pubescent with stalked capitate glands and with distinct ellipsoid green gland-dots; lower bracts elliptic; upper bracts obovate-oblanceolate, 18–28 x 3–8 mm, tip narrowing into a hard apical spine 5–10 mm long and 1–2 pairs of spinose teeth per side 2–5 mm long. Bracteoles 10–15 x 2–3 mm, linear-lanceolate, ending in a pungent mucro 2–3 mm long, glandular pubescent and ciliate, white on mid-vein and margin. Sepals whitish with green nerves and conspicuous scarious margin, minutely ciliate and glandular pubescent; dorsal sepal 10–13 mm long, 3-veined from the base, ovate or ovate-elliptic, narrowing gradually into a strongly mucronate apex c. 2 mm long; ventral sepal as dorsal but 2-veined from the base, veins merging into the apical spine; lateral sepals ca. 5 mm long, ovate-elliptic, with broad scarious margin, finely white veined. Corolla blue-violet with darker veins and cream-coloured throat, 15–20 mm long of which the tube ca. 2 mm long; limb 3-lobed, with basal lobes much reduced, central lobe obovate-spathulate, 6–8 mm wide, as long as or longer than wide, apex rounded to truncate, strongly constricted at the base, finely pubescent beneath, puberulous above with staight and hooked downward-directed bulbous-based hairs; callus not ribbed; filaments ca. 7 mm. long, glabrous apically, hairy towards the base, appendages absent; anthers 2–3 mm long; style ca. 10 mm long, deeply bifid, lobes ca. 1 mm long. Capsule and seeds not seen.

Ecology and distribution: —The type collection was made in in the Eyl area ( Fig. 4 ) in north-eastern Somalia. It is recorded as growing on limestone reefal at around 50–100 m altitude. According to Abbate et al. (1994) the geological substrate east of Eyl town is characterized by the Hafun (Xaafuun) succession composed of Miocene biogenic reefal limestones. This formation is widespread in Somalia and B. eilensis potentially has a wider distribution.

Etymology: —The specific epithet ‘ eilensis’ refers to the town of Eyl where this new Blepharis species was collected.

Risk assessment: — B. eilensis is known only from the type locality. No information was recorded about its abundance at the type locality. Due to the present political situation in this part of Somalia it has also been impossible to gather any further material or any information about the present conditions of the vegetation in the Eyl area . In view of the absence of any data about the status of its habitat and the nature and extent of threats ( Ullah & Gadain 2016), this species has to be assessed as Data Deficient (DD) ( IUCN 2019).

Affinities: — Blepharis eilensis is related to B. forgiarinii but differs in the mostly tridentate leaf apex, the sterile bracts being tranformed into sharply acuminate spines, the (1–)2–4-flowered spikes and the bract indumentum of stalked glandular hairs. It is distinctive among most species of sect. Acanthodium by having subequal dorsal and ventral sepals, a 3-lobed corolla limb and non-appendaged anterior pair of stamens.

Blepharis eilensis is related to B. forgiarinii and B. d iplodonta, also both endemic to north-eastern Somalia. These three species share the following feature not found otherwise in sect. Acanthodium : 3-lobed corolla limb (or with basal lobes much reduced) combined with the anterior filaments lacking a forward-directed appendage and the dorsal and ventral sepals appearing subequal. It is assumed that the presence of subequal dorsal and ventral sepals is a primitive character. The corolla in sect. Acanthodium is also typically 5-lobed limb and reduction to a 3-lobed limb is considered a derived condition. It is not clear if the absence of anther appendage in these species of sect. Acanthodium is primitive or the result of a secondary loss, although the combination with an advanced charcter like the 3-lobed corolla limb would suggest a derived state.

On the other hand the presence of stalked capitate glands on the bracts is considered to be an advanced stage. This type of hairs is found in many species of sect. Scorpioidea on floral leaves, bracts and sepals and in sect. Inopinata on sepals only. Glandular hairs are reported in sect. Blepharis only for a single collection of B. integrifolia from N Kenya (Gillett 13663), but otherwise have not been found in any species of sect. Acanthodium ( Vollesen 2000) .

Figures

FIGURE 1. Blepharis eilensis. A–C images of three individuals showing the plant habit.

FIGURE 2. Blepharis eilensis. A–B leaves, C lower sterile bract, D upper sterile bract, E detail of leaf showing the indumentum, F close up of fertile bract, G lower fertile bract, H upper ferile bract.

FIGURE 3. Blepharis eilensis. A bracteoles, B dorsal sepal, C ventral sepal, D lateral sepal, E close-up of corolla and anthers, F corolla tube and stamens.

FIGURE 4. Distribution map of Blepharis eilensis.