MONSTERA TARRAZUENSIS
PROTOLOGUE: Monstera tarrazuensis Croat & M.Cedeño, published in Nordic Journal of Botany 38-e02970: 5 (2020).
Monstera tarrazuensis Croat & M. Cedeño, sp. nov. Type: Costa Rica, San José: Tarrazú county, San Lorenzo district, road from Tarrazú to Quepos, 9°34′57,47″N, 84°4′2,53″W, 1400 m, 9 Jul 2019, M. Cedeño 1686 (holotype USJ!).
DISTRIBUTION: Costa Rica: Costa Rica.
DISTRIBUTION NOTE: Costa Rica: San José.
SPECIES DESCRIPTION:
Nomadic vine, appressed-climbing and pendent habit. Seedlings: bearing foliage leaves. Juvenile plants: root climbers; stems light-green with white dots, smooth; internodes 3–7 cm long, 3–5 mm diam.; petiole distinct, dark or light-green, smooth, 4–10 cm long, sheathed to base of the geniculum or blade; petiole sheath persistent; blades lanceolate, cordate at base, acuminate at apex, coriaceous, 7–14 × 5–9 cm, not appressed to the phorophyte; fenestrations absent. Adult plants: root climbers; stems dark green with white dots, smooth, cylindrical; internodes 4–11 cm long, 1.2–1.7 cm diam., 3.3–6.5 times longer than wide; anchor roots and feeder roots light-brown; petiole light-green with white dots, smooth, 11–14 cm long, sheathed along its entire length; petiole sheath persistent or rarely deciduous; geniculum obscure, 0.5–1.0 cm long; blades ovate to ovate-elliptic, rounded or asymmetrical at base, short-acuminate at apex, coriaceous, 13–26 × 7.5–13.8 cm, 1.5–2.0 times longer than wide, not decurrent on the geniculum, drying grayish or brown, faintly glossy; midrib ribbed adaxially, convex abaxially, drying dark brown; primary lateral veins 5–9 per side, departing midrib at 45–60°, slightly sunken adaxially, prominent abaxially, drying dark brown and wavy; secondary veins completely parallel to the primary lateral veins and finely wavy; collective veins scarcely visible; fenestrations absent; margins entire.⁴
INFLORESCENCE:
Inflorescences on pendent stems, arranged in the axils of the leaves; peduncle smooth, 13–15 cm long; spathe long-acuminate, open at apex and overlapping margins at the medial part, light green during development, white internally and greenish-white or creamy white externally at anthesis, 10–15 × 5–7 cm, up to 5 cm longer than the spadix, falling intact after anthesis; spadix oval, white during development, white at anthesis, 5–6 cm long, 2–3 cm diam.; basal sterile flowers 2.5–4.0 mm long, with a transparent stigmatic secretion; fertile flowers 3–4 mm long; stamens 2–4 mm long, with laminar filaments; anthers 1.5–2.0 mm long; ovary rectangular in longitudinal section, 2–3 × 1.5–2.0 mm; style hexagonal, 1.5–2.0 × 2–3 mm; stigmatophore absent; stigma linear, with a transparent stigmatic secretion; berries with a white stylar cap during development, mature stylar cap white-cream; pulp white; seeds unknown.⁴
ECOLOGY:
Endemic to Costa Rica in the central Pacific region, on Cerro Hormiguero, at 1100 to 1200 m elevation, occurring in Tropical wet forest and Premontane rain forest life zones. Flowering and fruiting have been recorded in July and September.⁴
DISTRIBUTION MAPS:
ETYMOLOGY:
The epithet tarrazuensis refers to the Tarrazú Cantón (county) in San José Province, where the type locality is found.²
NOTES:
1. The species is a member of sect. Monstera and is characterized by its long slender internodes, small narrowly ovate, entire blades which lack perforations and the inflorescences with a stubby spadix which is much shorter than the coriaceous caviform spathe that is yellowish on outside and creamy white inside as well as by the subterete, somewhat caviform styles and subcircular, barely raised stigma. Mostera tarrazuensis can be confused with Monstera luteynii, which also has hanging stems and leaf blade without perforations. But it differs because Monstera lutein has stems completely covered with pustules, leaf blade with tertiary venation strongly prominent on both surfaces and the terete geniculum.⁴
2. Conservation status: Monstera tarrazuensis it is not found in any protected areas.⁵
STORY:
STORY TITLE: Described already threatened
Monstera tarrazuensis was published in 2020 from the road between Tarrazú and Quepos on the Pacific slope of the Cordillera de Talamanca, in a paper whose title names the threat: the expansion of coffee plantations.² The species is not found in any protected area, its habitat is strongly impacted by that expansion, and the authors assessed it as Critically Endangered.² The two species described beside it, Monstera alfaroi from the same road and Monstera wilsoniensis from the Wilson Botanical Garden, were assessed as Endangered for the same reason.²
It is a small plant for the genus, with entire coriaceous blades only 13 to 26 cm long and inflorescences borne only on hanging stems, the margins of the spathe overlapping in their lower half.² Its nearest look-alike, Monstera luteynii, also hangs and also lacks perforations, but has stems covered with pustules and tertiary veins raised on both surfaces.²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Monstera tarrazuensis Croat & M.Cedeño
2. Nordic Journal of Botany 38-e02970: 5 (2020) — protologue.
3. iNaturalist: Monstera tarrazuensis
Additional photos from iNaturalist by Günter Gerlach