Monstera anomala Zuluaga & Croat, 2018

Zuluaga, Alejandro & Cameron, Kenneth M., 2018, Two new species of Monstera (Araceae: Monsteroideae) with entire leaves from Panama and Costa Rica, Phytotaxa 334 (1), pp. 1-9 : 2-5

Monstera anomala Zuluaga & Croat sp. nov. ( Figs. 1 , 2 )

Monstera anomala is easy to distinguish from other species in the genus with shingled juvenile leaves because its flowers have a long and constricted stylar region, 4–6 mm long, which is narrower than the ovary. It is most similar to M. acuminata Koch (1855 [App]: 4), but adult plants are more robust, with entire leaves lacking fenestrations, and with secondary and tertiary veins inconspicuous on the upper surface.

Type: — PANAMA. Veraguas: Distrito Santa Fe, corregimiento El Pantano, Parque Nacional Santa Fe, trail between alto Los Gonzales to alto El Viro, 800–1000 m. 8°33.162’N – 8°33.625’N, 81°4.586’– 81°4.767’W, 16 Jan 2013, A. Zuluaga, A. Doucette, E. Brantner & E. González 888 (holotype: WIS!, isotypes: PMA!, MO!).

Seedling stolon-like, on the forest floor, green, 1–3 mm diameter. Juvenile plants completely adpressed to the host (i.e., with shingled leaves); petioles less than 6 mm long; blades oblate to circular, 0.5–10 cm in diameter, size increasing gradually with the height on the host, asymmetrical, apex with a short acumen, suddenly switching to the adult shape. Pre-adult and adult stems adpressed to the host, circular in cross section, 1.5–2.8 cm across, internodes 3–7 cm long. Pre-adult and adult leaves exserted from the host, alternate, most of the leaves distichous, except for the ones close to the apex of the plant; petioles 20–50 cm long, 0.4–1.2 cm diameter, circular in cross section, departing at 45–90 degrees from the host, petiole sheathed for almost the entire petiole (excluding the geniculum); sheath marcescent, the base persistent as fibers; geniculum 1.8–3.8 cm long, 0.4–1.2 diameter; blades entire, very rarely with fenestrations or lobate, perpendicular to the host to slightly pendent, elliptical to oblong, 0.9–1.5 times longer than the petiole, 27–60 cm long, 9–20 cm width, 2.1–4.2 times longer than wider, symmetrical to asymmetrical, apex turning towards one side, upper surface bright green and glossy, lower surface paler appearing whitish, and matte, base obtuse, apex acuminate; main vein flat on upper surface, raised on lower surface, primary lateral veins sunken on upper surface, raised on lower surface, 10–15 per side, secondary lateral veins inconspicuous on upper surface, visible on lower surface; tertiary veins reticulate, inconspicuous. Plants flowering (6–) 10–20 m above the ground, inflorescence axillary, solitary; peduncle 6–14 cm long, 0.6–1.4 cm diameter, circular in cross section, green; spathe white at anthesis, 10–13 cm long, 1–3 cm longer than spadix; spadix terete in cross section, slightly narrower at apex, 12–22 cm long, 2.7–5 cm diameter, 1.7–2.8 times longer than peduncle. Flowers white, 15–22 in primary spiral, 17–25 in secondary spiral, 8–18 mm long; stamens four, filaments laminar, 3–4 mm long; anthers 2–3 mm long; ovary circular in cross section, 3–4 mm long, 3–4 mm diameter, 2-locular, two ovules per locule; style 3–5 mm long, 2–4 mm diameter, narrower than ovary in cross section, as wide as the ovary apically, hexagonal viewed from above, trichosclereids abundant in stylar region and reaching the ovary; stigma linear, 2–3 mm long. Fruiting spadix first green, yellow at maturity, 15–27 cm long, 5–8 cm diameter; stylar cap falling from fruits exposing the white aril. Seeds one per fruit, green–blue, 4–6 mm long, 3–4 cm wide, 1–2 mm thick; embryo green.

Distribution and ecology: — Monstera anomala ranges from North Central Panama to South Central Costa Rica, at elevations between 100–1200 m. This species grows high (10–20 m) into the canopy of humid premontane and montane forests ( Fig. 3 ).

Eponymy:— The epithet anomala (meaning anomalous or strange), was chosen because of the species’s unique combination of foliar and flower characters not common in other Monstera species.

Notes:— Monstera anomala has all the general characteristics of the species in the M. sect. Marcgraviopsis sensu Madison (1977). From among this group of species M. anomala is most similar to M. acuminata , a species widespread from Mexico to Panama. However, M. anomala differs from M. acuminata in having more coriaceous leaves, larger length/width leaf ratio, inconspicuous secondary lateral veins on the lower surface (vs. conspicuous), and flowers with a long and narrow style (vs. style as wide as the ovary) ( Table 1). Some young specimens of M. spruceana ( Schott 1859:40) Engler (1878: 115) with leaves lacking fenestrations could be confused with M. anomala ; however, M. spruceana is a more robust plant with deeply lobate leaves at maturity. Grayum and Croat first recognized several specimens of M. anomala as a different taxon, and assigned the name M. skutchii to several collections from Costa Rica. However, all these specimens were later identified as M. spruceana for the Araceae treatment of the Costa Rican Flora ( Grayum 2003). Morphologically M. spruceana is a distinctive species and its distribution throughout Central America is not clear.

Additional specimens examined (paratypes):— COSTA RICA. Cartago: Turrialba, along camino Raíz de Hule, south east of Platanillo ( Tsipirí ), 9°49’12’’N, 83°24’W, 1200–1400 m, 1 Jul 1976, T.B. Croat 36788 (MO) ; Turrialba, along Quebrada Platanillo near confluence of Quebrada Sipiri , Platanillo de Chirripó , 9°48’36’’N, 83°24’W, 1135 m, 2 Mar 1990, M.H. Grayum 9727 (CR, MO!) . Heredia: Sarapiquí, finca El Bejuco, S base of Cerros Sardinal , Chilamate de Sarapiquí. 10°27’N, 84°3’36’’W, 70–100 m, 2 Jun 1985, M.H. Grayum 5327 ( MO!) ; Sarapiquí, finca La Selva, Puerto Viejo de Sarapiquí , ridge near end of Pasos Perdidos , 10º25’N, 84º2’W, 120 m, 3 Jun 1985, M.H. Grayum 5356 (DUKE!, MO!) . Limón: hills 3.5 airline km S of Islas Buena Vista in the Río Colorado, 16 airline km SW of Barra del Colorado , premontane wet forest on low hills, 10°39’N, 83°40’12’’W, 10–120 m, 15 Sep 1986, G. Davidse 31269 ( MO!) ; along road between Puerto Viejo de Talamanca and Manzanillo, stretch from Quebrado Ernesto to Manzanillo , 9°37’48’’– 09°38’N, 82°40’48’’– 82°42’W, 5 m, 3 Nov 1984, M.H. Grayum 4352 (AAU, CR, MO!) ; Refugio Barra del Colorado, forests and pastures between Río Chirripocito and Río Sardina ( Sardinal on Chirripó Atlántico quadrangle), 10°37’48’’N, 83°45’W, 12 m, 21 Apr 1990, M.H. Grayum 9809 (CR, MO!) ; Talamanca, Cantón de Talamanca, Alto Urén , subiendo a Cerro Chun , siguiendo un antiguo camino de Quebrada Chaho a Alto Lari , 9°24’N, 83°19’48’’W, 800 m, 24 Jul 1989, G. Herrera – Chacón 3330 (CR, MO!) . Puntarenas: cantón Golfito, Esquinas forest, area between the Rio Esquinas and Palmar , 76 m, 17 Mar 1951, P. H. Allen 6017 ( NY!) ; Osa, hills north of Palmar Norte, along trail to Jalisco , 8°58’48’’N, 83°25’12’’W, 50–700 m, 21 May 1976, T.B. Croat 35187 ( MO!) ; along road between Rincón de Osa and Rancho Quemado, ca. 10 km W of main Rincón–Pto. Jimenez Road , 8°41’N, 83°32’30’’W, 150–260 m, 3 Mar 1985, T.B. Croat 59755 (CAS, GB, HNMN, MO!) ; along highway to Golfito from Panamerican highway at Río Claro , 2.5 mi SE of Golfito, 8°36’N, 83°3’36’’W, 60 m, 14 Sep 1987, T.B. Croat 67585 (HNMN, MO!) ; along road between Palmar Norte and Panamerican border, 3 km N of turn–off to Rincón , 8°48’39’’N, 83°16’18’’W, 110 m, 10 Sep 1996, T.B. Croat 79200 (INB, MO!) ; Rincón de Osa, along ridge between quebrada Aparicio and quebrada Aguabuena , 8°42’N, 83°30’36’’W, 200–400 m, 7 Oct 1984, M.H. Grayum 4015 (MO!, NY!) ; Between Golfo Dulce and Rio Térraba , 30 m, Dec 1974, A. F. Skutch 5320 ( US!) . San José: cantón Perez Zeledón, about 1 mile beyond divide between San Isidro del General and coastal town of Dominical , 9°16’12’’N, 83°51’36’’W, 900 m, 22 May 1976, T.B. Croat 35304 ( MO!) . PANAMA. Chiriquí: San Bartolo Limite , 18 km W of Puerto Armuelles, rainforest, 8°17’24’’N, 82°58’36’’W, 450 m, 24 Feb 1973, P. Busey 604 ( MO!) . Colón: Teck Cominco Petaquilla mining concession, forested slopes along ridge road, 8°49’28’’N, 80°39’29’’W, 110 m, 10 Mar 2008, G.D. Mcpherson 20496 (MO!, PMA!) . Panamá: Capira, cloud forest on Cerro Campana above Su Lin Motel , 8°43’N, 79°54’W, 209 m, 25 May 1971, T.B. Croat 14767 ( MO!) ; middle slopes of Cerro Campana, ca. 1 mi from Interamerican Highway , 8°43’9’’N, 79°53’25’’W, 150 m, 15 Jun 1976, T.B. Croat 35989 ( MO!) ; Panamá, vicinity of Cerro Jefe, 4.6 km beyond peak on road to Altos de Pacora , 26.3 km from the Inter–American Highway , 9°14’20’’N, 79°20’25’’W, 600 m, 12 Jun 1976, T.B. Croat 35914 ( MO!) ; Cerro Campana, 6.1 miles above Pan – American highway, 3.2 miles beyond park entrance and Guarda Bosque Station , 8°41’N, 79°56’W, 800 m, 23 Mar 1993, T.B. Croat 74767 (CM, MO!) . Veraguas: vicinity of Santa Fé, along dirt road from Santa Fé to Río San Luis , past Escuela Circlo Alto de Piedra , at Río Segundo Brazo (2nd stream below school on Atlantic Coast ), 8°33’N, 81°8’W, 480 m, 28 Jun 1987, T.B. Croat 66902 (MEXU, MO!) ; NW of Santa Fé, ca. 1km from Escuela Agrícola Alto de Piedra, Pacific slope, 8°31’22’’N, 81°7’35’’W, 800 m, 21 Dec 1974, S.A. Mori 4024 ( MO!) ; Santa Fé, along 1st branch of Río Santa María, roadside and forest a short way S of river, road from Santa Fé , 8°31’26’’N, 81°7’46’’W, 600 m, 26 Oct 1975, J.T. Witherspoon 8903 ( MO!) .

Figures

FIGURE 1. Comparison between Monstera anomala sp. nov. (A–F), and M.acuminata (G-I). M.anomala: A, juvenile plant with shingled leaves; B, young infructescence; C, mature infructescence with stylar caps falling off; D, Alfonso Doucette collecting adult plant with infructescence and leaves lacking fenestrations; E, adult leaf; F, young fruits in lateral view showing narrow stylar region of the flower. M. acuminata: G, adult leaf lacking fenestrations; H, adult leaves with fenestrations; I, inflorescence.

FIGURE 2. Illustration of Monstera anomala sp. nov. (Zuluaga et al. 888) A, fruit in lateral view; B, stem and infructescence; C, juvenile plant with shingled leaves; D, adult leaf showing venation pattern. Illustration by Sarah Friedrich.

FIGURE 3. Distribution map of Monstera anomala (circles) and Monstera integrifolia (stars).