MONSTERA BUSEYI
PROTOLOGUE: Monstera buseyi Croat & Grayum, published in Phytologia 82: 38 (1997).
Monstera buseyi Croat & Grayum, spec. nov. Type: COSTA RICA. Heredia: between Río Peje and Río Sardinalito, Atlantic slope of Volcán Barva, 10° 18.5’ N, 84° 04’ W, 480–520 m, 8 Apr 1986, M.H. Grayum 6877 (HOLOTYPE: MO-3486393!; Isotypes: B,CR!).
DISTRIBUTION: Costa Rica to SW. Panama: Costa Rica, Panama.
DISTRIBUTION NOTE: Costa Rica: Guanacaste, Heredia, Puntarenas, San José iNaturalist: Alajuela.
SPECIES DESCRIPTION:
Robust nomadic vine, appressed-climbing. Seedlings: bearing foliage leaves. Juvenile plants: root climbers; stems rough-pustular at apex (with black pustules), green, cylindrical or slightly flattened; internodes 2–4 cm long, 1.0–1.5 cm diam.; petiole distinct, light-green, rough-pustular with black pustules at base, 12–15 cm long, sheathed to base of the geniculum; petiole sheath semi-persistent; blades lanceolate, truncate at base, acuminate at apex, thinly coriaceous, 7–14 × 6–9 cm, not appressed to the phorophyte; fenestrations absent or present. Adult plants: root climbers; stems green, brown or gray, rough-pustular on leafy parts (with black pustules), cylindrical or slightly flattened; internodes 2–5(20) cm long, 1.0–3.0 cm diam., 1.6–2.0 times longer than wide; cataphylls deciduous or marcescent, light-green with a very reduced blade, black-pustular at base; anchor roots black; feeder roots gray and corky; petioles light-green, covered with black pustules along their entire length, rough-verrucose mainly at base, white-cream to pale pinkish internally, 20–75 cm long, sheathed 7–10 cm before base of the geniculum; petiole sheath semi-persistent; geniculum rough-verrucose, slightly ribbed adaxially and convex abaxially, 3–4 cm long; unsheathed portion flattened adaxially and convex abaxially; blades ovate to lanceolate-ovate or elliptic, broadly cuneate to truncate at base, acuminate at apex, thinly coriaceous to subcoriaceous, drying gray, blackish or olive-green (scarcely yellowish-green), 27–75 × 11–33 cm, (1.5)1.7–2.2 times longer than wide, decurrent-undulate over the geniculum (4–8 undulations of 1–4 mm wide), midrib slightly ribbed adaxially, convex abaxially, drying black or yellowish on both surfaces, primary lateral veins 35–65 per side, bifurcated or trifurcated, strongly sunken adaxially, prominent abaxially, departing midrib at 85–90°, drying black or yellowish; secondary veins prominent and reticulate; collective veins visible in blades with entire margins; fenestrations absent or present, arranged in a single series along the midrib when present; margins entire or pinnatilobed with 2–5 lobes per side.⁴
INFLORESCENCE:
Inflorescences on ascending stems, 1–3 simultaneously at flowering season, arranged in the leaf axils or into cataphylls; peduncle smooth or scarcely pustular, 17–30 cm long, 1–2 cm diam.; spathe short or long acuminate, light green to pruinose during development, white internally and cream-yellowish externally at anthesis, 7–22 × 10–13 cm, equal to or 4 cm longer than the spadix; spadix white during development, cream-white at anthesis, 6–20 cm long, 1.5–2.0 cm diam., (5)6–8(9) times longer than wide; basal sterile flowers 3–5 mm long; fertile flowers 5–7 mm long; stamens 1.2–7.0 mm long, with laminar filaments; anthers 1.5–2.0 mm long; ovary sub-conical in longitudinal section, 3.5–5.0 × 2.0–2.5 mm; style pentagonal or hexagonal, 1.2–2.0 × 4–5 mm; stigma linear, sunken on the top surface of the style; berries with a cream stylar cap, light-green during development; pulp white; seeds black, spherical, 5–7 mm long.⁴
ECOLOGY:
Monstera buseyi ranges from Costa Rica (Alejuela, Heredia, Puntarenas, San José) to Panama, (Chirquí) at 40–1450 m in Tropical wet forest life zones. Flowering has been recorded in January-July, November to December. Fruiting in March, June to November.⁴
ETYMOLOGY:
This new species, virtually endemic to Costa Rica, is dedicated to Philip Busey, formerly of the Missouri Botanical Garden, who made the first collection known to the authors (and the only one from Panama) on 22 Feb 1973.²
NOTES:
1. The species is a member of a sect. Monstera and is characterized by short internodes, pustular, obscurely whitish-speckled, brownish-roughened to sometimes weakly verrucose, U-shaped petioles, sheathed to geniculum, with the sheath deciduous or somewhat persistent, blades broadly cuneate to rounded, truncate or subcordate at base and marginally entire to pinnately 4–5 lobed or with 1–2 large perforations or sinuses as well as by peduncle being longer than the spathe, the latter greenish white outside, pale yellowish to white within and with the spadix usually 6–8 times longer than wide and mature white berries. Monstera buseyi is closely related to Monstera alfaroi and both have tuberculate petioles. Most collections of Monstera buseyi have narrowly ovate-elliptic blades 2.0–2.5 times longer than broad which dry medium grayish yellow-brown above and much paler, yellowish green and often matte below (less frequently dark brown above and dark gray-brown and semiglossy below with the blades only 1.7 times longer than wide) with the flowering spadices 6–9 cm long, to ca. 1 cm diam. and with the infructescences to 12 cm long. In addition, the blades of Monstera buseyi have leaf blades with the primary lateral veins usually branching once or twice near the midrib then with the branches extending closely parallel along the primary lateral vein to the margin. In contrast Monstera alfaroi, known from the Cordillera de Talamanca and in the Fila Tinamaste, have more broadly ovate blades only 1.6 times longer than wide, drying blackened, with the lower surfaces drying semiglossy and with much larger inflorescences, ranging from 17 cm long post-anthesis to 22 cm long in early fruit.⁴
2. Conservation status: Monstera buseyi is protected in the Reserva Biológica Alberto Manuel Brenes, Reserva Biológica del Bosque Nuboso Monteverde, Parque Nacional Rincón de la Vieja, Parque Nacional Guanacaste, Parque Nacional Braulio Carrillo and Refugio Nacional de Vida Silvestre Golfito.⁵
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Monstera buseyi Croat & Grayum
2. Phytologia 82: 38 (1997) — protologue.
3. iNaturalist: Monstera buseyi
Additional photos from iNaturalist by Alex Castelein, Aidan Witthoff, LostInCR, Eva Hedström and jmole