Volume 43 ROIDEANA Nos 3&4 International Aroid Society, Inc. December 31,2020 A ISSN 2310-0745 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... A New Species of Spathiphyllum (Araceae) from the Ecuadorian Oriente Thomas B. Croat Missouri Botanical Garden 4344 Shaw Blvd. St. Louis, MO 63110, U.S.A. Nils Weessies Kalmoesstraat 151 7322NM Apeldoorn The Netherlands ABSTRACT INTRODUCTION A new species of Spathiphyllum, S. At present only 49 species of ivanportillae Croat & N. Weessies, is Spathiphyllum have formally been published described from cultivated material (Boyce & Croat, 2020) with another 40 new originating from eastern Ecuador near the species awaiting publication (Croat, in Peruvian border. The species is a member prep.), one of which is described here. The of section Amomophyllum and stands out for genus is largely neotropical and recent its extraordinarily dark leaves. It is seemingly molecular studies have verified its most similar to Spathiphyllum schomburgkii monophyly (Zuluaga et al, 2015). A revision Schott and S. neblinae G. S. Bunting, both of of the Central American species is which are from the region of the completed and will soon be published Venezuelan Guayana and are moderately (Croat & Ortiz, in prep.). small plants with elliptic blades, two-locular ovaries with 2–5 ovules per locule. While some species in South America are wide ranging eg. Spathiphyllum cannifolium (Dryand. ex Sims) Schott, most species are KEY WORDS relatively narrowly ranging or endemic and Ecuador, Spathiphyllum, new species, sect. some are known only from type collections. Amomophyllum. Unlike several other aroid genera (Adelonema, Anthurium, Monstera, Philodendron, Rhodospatha, Stenospermation), which are most Aroideana VOL 43 NOS 3&4, 2020 22 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... Figure 1. Flowering plant in the field. Photographer unknown. Aroideana VOL 43 NOS 3&4, 2020 23 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... Figure 2. Potted plant in flower. Aroideana VOL 43 NOS 3&4, 2020 24 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... Figure 3. Adaxial blade surface showing dark green glossy surface. Aroideana VOL 43 NOS 3&4, 2020 25 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... Figure 4. Leaves showing weakly glossy abaxial blade surface and adaxially 3-ribbed petiole. Aroideana VOL 43 NOS 3&4, 2020 26 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... species-rich in the wetter forests of NW (Croat & O. Ortiz, in prep.) and in addition Ecuador, Colombia and Panama, had just completed a thorough survey of Spathiphyllum is weakly represented there South American species. The new species with only 5 species (S. friedrichsthalii, S. described here matched no other species. floribundum, S. grandifolium, S. phryniifolium Here we describe Spathiphyllum ivanportillae, a and S. wendlandii) occurring in the very wet recent discovery from the Morona-Santiago Chocó Biographical Region indicating a low Province, Ecuador. presence for this genus in the wettest area of South America. TAXONOMIC TREATMENT The South American species new to Spathiphyllum ivanportillae Croat & N. science are mostly known from the eastern Weessies, sp. nov. Type: Ecuador. slopes of the Andes into the middle Morona-Santiago: along road from Amazon basin. Relatively few Spathiphyllum Patuca to Puerto Morona, collector are known from the Mata Atlantica in unknown, voucher prepared from eastern Brazil or in the lower Amazon basin. cultivated collection (Missouri Alternatively, the Guiana Highlands, the Botanical Garden 2019–1847), 10 sandstone area of northeastern South Sep. 2019, T. B. Croat & N. Weessies America in Guyana and in Venezuela 107868 (holotype, MO-6941180; (Amazonas and Bolívar) is an area of high isotypes, COL, K, L, M, NY, QCNE, species diversity and is likely to contribute US). Figures 1–8. even more species once the area is more fully explored. Small solitary terrestrial herb to 25 cm tall; Stem erect; internodes 3–7 mm long, near Within the past year an especially apex, to 1.3 cm lower down, dark green, 7 attractive species of Spathiphyllum has been mm diam. LEAVES with a rosulate habit introduced into cultivation by two of the with petioles (7.0–)7.6–10.5 cm long (avg. plant dealers from Ecuador. The first 7.5 cm), sheathed 0.6–0.84 its length; specimen seen by the senior author was at sheath 4.8–7.3 cm long, acute at apex, pale the International Aroid Society’s Annual green, soon thin and scarious, frequently Show and Sale in Miami in September, breaking up; free part 1.7–3.2 cm long, 2019. The same species became available in medium green, semiglossy, flattened Europe at about the same time and co- adaxially with weakly raised margins, 3- author Nils Weessies acquired the plant as ribbed abaxially, the sides subparallel, 1–2- well. Correspondence between Croat and ribbed; geniculum 6–9mm long, slightly Weessies led to investigations which proved thicker than petiole, weakly orange, 3- that the species was new to science. The ribbed, ribs undulated; blades 9.6–12.8(– senior author had just completed the 13.0) cm long (avg. 11.14 cm), with a width Araceae treatment for Central America of 4.7–5(–6.7 cm) (avg. 5.76 cm) and 1.7– Aroideana VOL 43 NOS 3&4, 2020 27 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... 2.2(–2.3) times longer than wide (avg. 1.9 2-locular, 1.5 mm wide, tapering outward to times) elliptic, 1.15(–1.2)–1.82 times longer thickened style; style mammiliform, 1 mm than petioles, acute to weakly short- long, 2 mm wide, white, protruding 1 mm acuminate at apex, attenuate at base, dark above tepals; stigma a narrow slit 0.5 mm green and semiglossy above, moderately long; ovules 3 per locule, basal, 0.6–0.8 mm paler, semiglossy, greenish weakly tinged long, funicle 0.4–0.6 mm long; stamens purplish below; midrib obtusely sunken erect, weakly emerging above the edge of and concolorous above, narrowly rounded the tepals or sometimes with lower portion and concolorous below; drying broadly held by the subtending tepals; anthers white, rounded and concolorous above, sub- ca. 1 mm long, thecae oblong-ellipsoid, not round-raised and mostly 3-ribbed, divaricate, extruding pollen in slender concolorous below; primary lateral veins threads from the terminal pores; pollen 3–4 pairs, arising at a 35–40° angle, etched white, pollen shed occurred for up to 20 and weakly quilted-sunken above, weakly days. INFRUCTESCENCE with dark green raised and concolorous below, drying spathe persistent, ca. 0,9 cm diam., 4 cm scarcely discernable above, weakly raised long, dark green; Berries white, and slightly darker below; interprimary veins subrounded, ca. 5 mm long, ca. 6 mm diam., etched above, weakly sunken below, drying truncate-shallowly caviform at apex with scarcely raised and visible below; upper raised style almost equaling the height of surface drying finely and closely striate; the rim, apex brownish; dried stigma black; lower surface drying densely thick-granular Seeds 0–2 per berry, cochleate, medium and sparsely short-pale-lineate. dark brown, 3 mm long, 1,5 mm wide, 1,5 INFLORESCENCES erect, up to three mm thick, prominently 7–9-ribbed, the ribs produced from different leaf axils in rapid thickly tuberculate, the inner margin deeply succession with each inflorescence lasting sulcate. from 2 to 3 weeks; peduncles 17.8(–20)–29 cm long, 1.5 mm diam., dark green, thicker Spathiphyllum ivanportillae is endemic to 2 mm diam., purplish in apical 1.5 cm; Ecuador, known only from Morona- spathe 3.6–4.5 cm long, 2.0–2.3 cm wide, Santiago Province at 200 m elevation in a weakly glossy on inner surface, glossy on Tropical moist forest life zone. outer surface, white on both sides, midvein dark green below, diverging at 80–90° from The species is placed in sect. spadix; spadix 3.3–3.5 cm long, stipitate 7 Amomophyllum Engl. for its free perianth mm long (stipe sometimes tinged purplish segments and subtruncate pistils . It is violet, 3 mm diam.); flowers 3–4 visible per seemingly most similar to Spathiphyllum spiral, 2.5 mm long, 2.3 mm wide; tepals 4, schomburgkii Schott and S. neblinae G. S. dark brown at pistillate anthesis to bright Bunting, both of which are from the region orangey red at staminate anthesis, lighter at of the Venezuelan Guayana and are apex, free to base; pistils 1.7 mm long; ovary moderately small plants with elliptic blades, Aroideana VOL 43 NOS 3&4, 2020 28 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... Figure 5. Inflorescence in side view at pre-anthesis, tepals lavender-purple and pistils whitish. Aroideana VOL 43 NOS 3&4, 2020 29 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... Figure 6. Spathe and spadix in face view at preanthesis. Aroideana VOL 43 NOS 3&4, 2020 30 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... Figure 7. Spadix at anthesis showing reddish violet purple tepals with anthers beginning to emerge. Aroideana VOL 43 NOS 3&4, 2020 31 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ... Figure 8. Close up of spadix showing anthers shedding pollen in elongate clusters. All photos (except the first one) by Nils Weessies. Aroideana VOL 43 NOS 3&4, 2020 32 Croat and Weessies, 2020 A New Species of Spathiphyllum (Araceae) from the Ecuadorian ..