Wittmackia caymanensis (Britton ex L.B.Sm.) Aguirre-Santoro (2017: 633)

Aguirre-Santoro, Julián, 2018, Taxonomic revision of the Caribbean-endemic species of Wittmackia (Bromeliaceae), Phytotaxa 336 (2), pp. 101-147 : 114-115

3. Wittmackia caymanensis (Britton ex L.B.Sm.) Aguirre-Santoro (2017: 633) . Basionym: Hohenbergia caymanensis Britton ex Smith (1935: 150) . TYPE:— CAYMAN ISLANDS. Grand Cayman, Winter 1890–1891, J.T. Rothrock 495 (holotype NY!)

Plant epiphytic, cespitose; rosette broad. Leaves 15 to 30 in number, 69–95 cm long, coriaceous; sheaths conspicuous, oblong, 12–21 × 9–12 cm, pale brown, lepidote on both surfaces, serrulate, occasionally entire; blades lingulate, 60–83 cm long, 5–12.7 cm wide at the base, 5.1–10.8 cm wide in the middle, light green to dark green, occasionally maculate, both surfaces smooth, lepidote abaxially, glabrescent adaxially, apex initially obtuse to rounded, then ending in a sharp and acuminate mucro, margins serrulate, the teeth evenly distributed, hook-shaped or triangular, straight to extrorse, green, 0.4–0.6 mm long. Inflorescence erect to inclined; peduncle almost completely exposed out of the rosette, stout, rigid, 68–77 cm long, 8–12 mm in diameter, green, sparsely floccose, central internodes 1.8–5.1 cm, distal internodes 3.8–4.3 cm; peduncle bracts longer than the internodes, marcescent, membranaceous, nervose, light-green, occasionally dull-red; the central ones erect, imbricate, linear-lanceolate, 10–11 × 1–1.2 cm, lepidote to floccose on both surfaces, apex acuminate, margins serrulate, teeth irregularly distributed, the distal ones suberect, imbricate, linear-lanceolate, 9.2–9.5 × 0.7–0.9 cm, lepidote to floccose on both surfaces, apex acuminate, margins serrulate, the teeth irregularly distributed, apex acuminate; the fertile part of the inflorescence conical, 28–55 cm long, 7.2–10.2 cm wide in the middle, 1-divided, occasionally 2-divided, branches (24–) 40 to 65 in number, rachis straight, green, 21–50 cm long, 5– 7 mm in diameter, floccose. Primary bracts similar to the peduncle bracts, gradually diminishing in size towards the apex of the inflorescence, diverging from the rachis to divaricate, marcescent, membranaceous, nervose, longer than the branches; the basal ones linear-lanceolate, 7.2–9.8 × 0.5–0.7 cm, light-green, occasionally dull-red, lepidote, apex attenuate, margins serrulate, occasionally entire, teeth irregularly distributed; the apical ones lanceolate, 1.6–2.5 × 0.1– 0.2 cm, light-green occasionally dull-red, floccose on both surfaces, apex attenuate, serrulate, occasionally entire, the teeth irregularly distributed. Spikes cylindrical, ovoid, 2.6–3.7 cm long, 1.2–2 cm wide in the middle; stipe exposed, 6–18 mm long, 2–3 mm in diameter, terete, floccose, 18– 30 flowered; rachis straight, 2.6–3.7 cm long, green. Floral bracts gradually diminishing in size towards the apex of the spike, partially enfolding the ovaries, imbricate, forming an angle of 30º–60º with the rachis, slightly concave, membranaceous, ovate to lanceolate, 3.5–6.1 × 3.3–4.8 mm, green to pale brown, nervose, ecarinate, sparsely floccose, apex acuminate, gradually turning into a sharp mucro of 4.8–5.8 mm long, margins minutely serrulate. Flowers suberect, 3.5–6.1 mm long. Calyx dorsiventrally compressed; sepals coriaceous, asymmetrical, 3.6–4 mm long, 2.2–3.2 mm wide at the base, the unwinged side 0.5–1.1 mm wide, the winged side 1.2–2.2 mm wide, green, sparsely floccose, entire, mucronate, mucro 1.9–5 mm long. Corolla tubular, apically spreading; petals oblong-lanceolate, 8.3–9.3 × 1.2 mm, green, glabrous, entire, apex acute; petal appendages flanking the antepetalous stamens, originating at 1.7 mm from the petal base. Stamens included; filaments 7.4–8.4 mm long, 0.2 mm in diameter; anthers 2.2 × 0.6 mm. Ovary ovoid, 2.9 mm long, 3.9 mm in diameter; epigynous tube 1.1 mm long. Style 9 mm long; stigma 1.2 mm long. Fruits globose, 7.4–11.5 mm long, 4.3–7 mm in diameter, green, glabrescent to sparsely floccose. Seeds more than 20 per fruit, club-shaped, 2.4 × 0.6 mm, stramineous to reddish-brown ( Fig. 5 ).

Etymology:— The specific epithet refers to the Cayman Islands, where the type specimen was collected.

Distribution, habitat, and phenology:— Wittmackia caymanensis was thought to be endemic to Grand Cayman in the Cayman Islands at 0–20 m elevation. However, this species was recently found in the Colombian island of Providencia at 0–70 m elevation ( Fig. 2 ). It forms large but highly localized populations in shaded areas of forested limestone formations. Collected in flower between November and March.

Conservation status:— According to Burton et al. (2014), Wittmackia caymanensis is categorized as Critically Endangered (CR B1ab(i,ii,iii,iv,v) + 2ab(i,ii,iii,iv,v)), mainly because of its extremely reduced area of occupancy and imminent threat provided by the expansion of urban areas in George Town. The recent discovery of this species in Providencia island ( Colombia) does not represent a significant decrease in the level of risk for this species for four main reasons: 1) the area of this island does not exceed 20 Km 2; 2) only two populations of the species are known to occur in the island; 3) the rapid gowth of the tourism infrastructure in the island represents a serious threat for the species; and 4) the natural forests of the island are not protected by national environmental agencies.

Taxonomic comments and affinities:— Wittmackia caymanensis resembles W. mesoamericana and W. rohan-estyi by its floccose inflorescence rachis, primary bracts much longer than the inflorescence branches, clearly stipitate spikes, long floral bract mucros (4–5 mm long), and long sepal mucros (2–5 mm long). Wittmackia caymanensis , however, differs from W. rohan-estyi by its shorter stipes (6–18 mm vs. 19–39 mm long), green corollas (vs. white), and shorter and narrower petals (8–9.5 × 1.2 mm vs. 11.2 × 3 mm). In the second case, W. caymanensis can be separated from W. mesoamericana by its narrower leaf blades (5–12.7 cm vs. 14 cm wide at the base); longer (6–18 mm vs. 3–5 mm long) and more slender stipes (2–3 mm vs. 4–5 mm in diameter); narrower spikes (1.2–2 cm vs. 2.2–2.7 cm wide); shorter flowers (13.5 mm vs. 16–17.3 mm long); shorter and narrower petals (8.3–9.3 × 1.2 mm vs. 12.5–13.4 × 2.4–3 mm); and petal appendages detaching at 1.7 mm from the petal base (vs. 3.1–4.2 mm). In the protologue W. caymanensis is compared with W. spinulosa from which it differs for its divergent branches laxly arranged along the inflorescence rachis and much longer stipes (vs. subsessile).

Additional specimens examined:— CAYMAN ISLANDS. Grand Cayman: without exact locality, Aguirre-Santoro 1509 flowered in cultivation at the Marie Selby Botanical Gardens, 21 June 2011 ( SEL!) ; 1.5 miles southeast of Georgetown, 10–20 m, 6 September 1969, Proctor 31031 ( IJ!) ; George Town, flowers subdivision near the High School on Carmen and Oslie Godfrey land, 0–20 m, 14 December 1991, Roulstone 10 ( CAYM!) . COLOMBIA. San Andrés y Providencia: Providencia, trocha entre playa suroeste y playa Manzanillo, aproximadamente a 500 m al noroccidente de playa Manzanillo , 70 m, 13º19’34.8”N, 81º23’06.7”W, 21 December 2013, Aguirre-Santoro 1949 ( COL!) ; Providencia, entre suroeste y Bahía Manzanillo , 5 m, 19 July 1990, Lowy et al. 146 ( COL!) .

Figures

FIGURE 2. Geographic distribution of the Caribbean-endemic species of Wittmackia. A. Species occurring in Jamaica and Cuba, and species endemic to the western Caribbean. Star: W. caymanensis, triangle: W. mesoamericana, circle: W. penduliflora. B. Species endemic to Puerto Rico. Star: W. portoricensis, circle: W. antillana. C. Species endemic to Jamaica. Circle: W. laesslei, triangle: W. negrilensis, star: W. polycephala.D. Species endemic to Jamaica. Circle: W. rohan-estyi, triangle: W. spinulosa, star: W. urbaniana. E. Species endemic to Jamaica. Circle: W. fawcettii, triangle: W. jamaicana, star: W. inermis. F. Species endemic to Jamaica. Circle: W. abbreviata, star: W. distans, square: W. eriostachya.

FIGURE 5. Wittmackia caymanensis. A. General habit of the plant. B. Infructescence. C. Spike. D. Flower conserved in liquid. E. Sepals. F. Apical portion of the stamen. G. Apical portion of the style and stigma. H. Fruit. I. Seed. (A: Aguirre-Santoro 1949; B–C and H–I: Aguirre-Santoro 1509; D–G: Rothrock 495; Photos of living specimens: J. Aguirre-Santoro).