MONSTERA GLAUCESCENS
PROTOLOGUE: Monstera glaucescens Croat & Grayum, published in Phytologia 82: 44 (1997).
Monstera glaucescens Croat & Grayum, spec. nov. Type: COSTA RICA. Heredia: Estación Biológica La Selva, at confluence of Río Sarapiquí and Río Puerto Viejo, Atlantic slope, 10° 26′ N, 84° 01′ W, 50–75 m, 5 Nov 1988, M. Grayum 8972 (HOLOTYPE: MO-3670954!).
DISTRIBUTION: SE. Nicaragua to NW. Colombia: Colombia, Costa Rica, Nicaragua, Panama.
DISTRIBUTION NOTE: Colombia: Chocó Costa Rica: Heredia iNaturalist: Limón.
SPECIES DESCRIPTION:
Nomadic vine, appressed-climbing. Seedlings: bearing foliage leaves. Juvenile plants: root climbers; stems dark green, smooth and pruinose, cylindrical; internodes 3–8 cm long, 3–5 mm diam.; petioles distinct, dark green, smooth, 4–7 cm long, sheathed up to half their length; petiole sheath persistent; blades lanceolate, truncate at base, acuminate at apex, subcoriaceous, 9–15 × 4–7 cm, not appressed to the phorophyte; fenestrations absent. Adult plants: root climbers; stems light to dark green, smooth and pruinose; internodes 2–3(10) cm long, 1.0–2.5 cm diam., 1.2–2.0 times longer than wide; cataphylls light-green or light green-pruinose, persistent or deciduous; anchor roots light brown; feeder roots dark brown; petiole light green and pruinose, smooth, 25–45 cm long, sheathed to half or 3 cm below base of the geniculum; petiole sheath persistent and closed; unsheathed portion slightly ribbed; geniculum smooth, slightly sunken adaxially, convex abaxially, 1.0–2.5 cm long; blades ovate to elliptical, broadly cuneate to rounded, truncated or subcordate at base, acuminate at apex, subcoriaceous, drying glossy, light brown, reddish or black, 25–45 × 15–30 cm, 1.4–1.7 times longer than wide, decurrent on the geniculum, decurrent portion 1–2 mm wide; midrib ribbed adaxially, convex abaxially, drying reddish or black on both surfaces; primary lateral veins 6–18 per side, occasionally two of them emerge together from the midrib and then spreading towards the margin, sunken adaxially, prominent abaxially, departing midrib at 55–65°, drying reddish and black; secondary veins reticulate towards the margin; collective veins not visible; fenestrations absent; margins entire or deeply pinnatifid with 2–7 lobes per side.⁴
INFLORESCENCE:
Inflorescences on ascending stems, 1 or 2 simultaneously at flowering time, arranged in the leaf axils or into cataphylls; peduncle smooth, 12–25 cm long; spathe acuminate and completely open at apex, with overlapping basal margins, yellowish green during development, creamy white externally and white internally at anthesis, marcescent and turning dark blue at the end of anthesis, 15–22 × 9–14 cm, up to 12 cm longer than the spadix; spadix white during development, cream at anthesis, 4–10 cm long, 1.0–3.0 cm diam., 3.5–5.0 times longer than wide; basal sterile flowers with a spherical ovary and a conical stigmatophore, with an orange stigmatic secretion, 4–5 mm; fertile flowers 4–6 mm long; stamens 1–5 mm long, with laminar filaments; anthers 2–3 mm long; ovary cylindrical, rectangular in longitudinal section, ribbed, 3–4 × 2–3 mm; style compressed and hexagonal, 0.5–2.0 × 3–4 mm; stigma linear, cleft on top surface of style, with an orange stigmatic secretion; berries with a yellowish green stylar cap during development, mature stylar cap creamy; pulp white; seeds dark-brown, globose, 5–7 mm long.⁴
ECOLOGY:
Monstera glaucescens ranges from southeastern Nicaragua and Costa Rica (Atlantic slope) to E Panamá and Colombia (Chocó), at 0–850 m, in Tropical wet forest and Premontane wet forest life zones. Flowering has been recorded in January and October. Fruiting in January-February, April, June, and November-December.⁴
ETYMOLOGY:
From Latin glaucescens, "becoming glaucous," referring to the glaucous parts that distinguish it from Monstera dissecta and Monstera pinnatipartita.²
NOTES:
1. The species is a member of sect. Monstera. It differs from the other species of the genus in Costa Rica by its light green, pruinose petiole, sheathed to half or 3 cm below the base of the geniculum, persistent and closed petiolar sheath, pinnatilobed leaf blade without fenestrations, the externally and internally white/cream acuminate spathe, and sterile flowers with the ovary spherical and with a conical stigmatophore. It is similar to Monstera pinnatipartita, but the latter species has persistent, involute petiolar sheaths, the leaf blade deeply pinnatifid, and occurs only on the Pacific slope. The species is not easily confused with any other but could be confused with Monstera bocatorensis which has the pinnae of the blade markedly unequal and drying light-yellow brown on the lower surface. In contrast Monstera glaucescens has leaf blades that dry dark brown and have much narrower pinnae with more long-tapered more prominently falcate pointed lobes.⁴
2. Conservation status: Monstera glaucescens is protected in the Zona Protectora Río Banano, Estación Biológica La Selva, Reserva Biológica La Tirimbina, Reserva de Vida Silvestre Barra del Colorado, Reserva Indígena Talamanca, Reserva Indígena Tayni, Parque Nacional Tortuguero, Parque Nacional Guanacaste, Parque Nacional Barbilla.⁵
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Monstera glaucescens Croat & Grayum
2. Phytologia 82: 44 (1997) — protologue.
3. iNaturalist: Monstera glaucescens
Additional photos from iNaturalist by njweess, Oliver Ingold and thesoulflowers
Additional photo from Wikimedia Commons by User45732
