Euphorbia blepharadena O.L.M.Silva & Cordeiro

Silva, Otávio Luis Marques da, Braun, Pierre, Riina, Ricarda & Cordeiro, Inês, 2021, Three new species of Euphorbia subgenus Chamaesyce (Euphorbiaceae) endemic to Brazil, European Journal of Taxonomy 733, pp. 72-86 : 74-76

Euphorbia blepharadena O.L.M.Silva & Cordeiro sp. nov.

urn:lsid:ipni.org:names:77214813-1

Figs 1–2

Diagnosis

Euphorbia blepharadena O.L.M.Silva & Cordeiro sp. nov. is similar to Euphorbia foliolosa Boiss. but differs in its smaller leaves with a denser indumentum composed of long (ca 1 mm) trichomes, cyathial glands with digitate appendages and pubescent ovary /fruit.

Type

BRAZIL • Minas Gerais, Jaíba, Furados , “ lado direito da Estrada Jaíba – Mocambinho” [right side of the road Jaíba – Mocambinho]; 15°12′37″ S, 43°51′33″ W; 19 Oct. 2001; J.A. Lombardi et al. 4433; holotype: UEC[018613] ; isotype: BHCB[64825] .

Etymology

The epithet is a reference to the cyathial gland appendages, which look like eyelashes on these glands ( Fig. 1G ).

Description

Erect monoecious herbs, up to 30 cm tall; underground system not seen; latex white. Stems terete, irregularly branched, brown when dried, pubescent, with short (<0.25 mm) curved and longer (ca 1 mm) erect simple trichomes. Leaves opposite, persistent, subsessile (petioles reaching up to 1 mm long); stipules interpetiolar, deltoid, inconspicuous (up to 1 mm long), apex fimbriate, indumentum of erect, long (ca 1 mm), simple trichomes; leaf blade membranaceous, pilose on the adaxial surface and densely pilose on the abaxial surface, both surfaces with erect, long (ca 1 mm), simple trichomes, discolorous (abaxial surface slightly lighter), elliptic to oblong, 0.5–0.8(–1) × 0.15–0.2 cm, base asymmetric, margin serrate with a colleter at the apex of each tooth, apex acute, venation hyphodromous. Cyathia solitary, axillary, subsessile; peduncle up to 1.5 mm long, with a few scattered erect, long (ca 1 mm), simple trichomes; involucre turbinate, 1.5–2.5 × 0.8–1.3 mm, actinomorphic, pilose on the outer surface, with erect, long (ca 1 mm), simple trichomes; involucral lobes triangular, pale to greenish when dried, margin fimbriate; cyathial glands 4(5), dark when dried, transversely elliptic and slightly concave, smooth, glabrous, 0.2–0.3 × 0.2–0.3 mm; cyathial gland appendages 6–8-digitate, lobes linear, 1.5–1.8(–2) mm long, white when dried, glabrous. Staminate flowers 25–35, arranged in (4)5 cincinni with 6–7 flowers each; bracteoles lanceolate, ciliate; pedicels up to 2 mm long, filaments up to 1 mm long, anthers ca 0.5 mm wide, dorsifixed, extrorse, transversely dehiscent. Pistillate flowers ca 7 mm long; pedicel up to 2.5 mm long; ovary globose, ca 1.5 × 1.5 mm, densely pubescent, with erect, long (ca 1 mm), simple trichomes; styles 3, 3.5–4 mm long, united only at the base, entire and slightly revolute at the apex, glabrous. Capsules 3-lobed, subglobose, 3.0–3.5 × 3.5–4 mm, pubescent, with erect, long (ca 1 mm) simple trichomes, green; pedicel shortly accrescent, reaching up to 4 mm long; columella 2–2.5 mm long; seeds brown, ovoid, ca 2 × 1 mm, tetragonous in cross section, testa shallowly tuberculate.

Distribution, ecology, and phenology

Euphorbia blepharadena sp. nov. occurs in clay soils in flat rocky outcrops (ʻlageadoʼ) in northeast Minas Gerais, within the Cerrado domain ( Fig. 2 ). The only specimen found so far was collected in October with both flowers and fruits.

Provisional conservation status

Euphorbia blepharadena sp. nov. is only known from a single locality ( Fig. 2 ), with AOO <10 km ² and EOO <100 km ². Its habitat is subjected to continuing decline in area, extent and quality. In the light of this, our evaluation suggests it to be classified as Critically Endangered (CR; B2ab[iii]).

Figures

Fig. 1. Euphorbia blepharadena O.L.M.Silva & Cordeiro sp. nov. A. Habit. B. Detail of indumentum on branches, with curved short and longer erect trichomes. C. Leaf. D. Detail of leaf blade margin, showing a colleter at the apex of each tooth. E. Cyathium. F. Opened cyathium, showing staminate cymules and bracteoles. G. Isolated cyathial gland, with its fimbriate appendage. H. Young fruit. I. Seeds in ventral (left) and dorsal (right) views. Illustration of the holotype, J.A. Lombardi et al. 4433 (UEC), by Klei Souza.

Fig. 2. Geographical distribution ofEuphorbia blepharadena O.L.M.Silva & Cordeiro sp. nov. (triangle), E. longipedunculata O.L.M.Silva & Riina sp. nov. (star) and E. sobolifera O.L.M.Silva & P.J.Braun sp. nov. (square).