Monstera guzmanjacobiae Díaz-Jiménez, M.Cedeño, Zuluaga & Aguilar-Rodríguez, Phytotaxa

Croat, Thomas B., Cedeño-Fonseca, Marco & Ortiz, Orlando O., 2024, Revision of Monstera (Araceae: Monsteroideae) of Central America, Phytotaxa 656 (1), pp. 1-197 : 97

24. Monstera guzmanjacobiae Díaz-Jiménez, M.Cedeño, Zuluaga & Aguilar-Rodríguez, Phytotaxa 437 (1): 039– 046. 2020. ( Figs. 44 , 45 )

Type: — MEXICO. Veracruz: Municipio Catemaco, La Palma, Selva alta perennifolia, 18º33’21’’N, 95º03’35’’W, 56 m, 31 May 2014, Pedro Díaz Jiménez & Valeria Guzmán Jacob 1305 (holotype MO!, isotypes MEXU!, XAL!) .

Nomadic vine, appressed-climbing with pendent branches. SEEDLINGS: filiform. JUVENILE PLANTS: root climbers; stems smooth, light-green, dorsiventrally compressed; internodes 4–8 cm long, 3–5 mm diam.; petiole inconspicuous, 1.0– 2.5 cm long; blades obovate, cordate at base, short-acuminate at apex, coriaceous, 6–9 × 5–8 cm, occasionally white spotted, completely appressed to the phorophyte; fenestrations absent. ADULT PLANTS: root climbers; stems dark green, scaly or with a light brown, thin and exfoliating epidermis, sometimes semiglossy, slightly with greenish pustules, rarely smooth, sulcate on one side; internodes 6–12 cm long, 0.8–2.5 cm diam., 4.8–7.5 times longer than wide; cataphylls deciduous; anchor roots brown; feeder roots beige and corky, up to 35 cm long; petiole matte-green, glaucous towards base, smooth towards the geniculum, striated at base, scarcely white-spotted, 15–25(30) cm long, sheathed up to 1.5 cm before or to base of the geniculum; petiole sheath marcescent with fibrous fragments, apically prolonged as a ligule 1.5–3.0 cm long; geniculum light or dark green, smooth or striated, terete, 0.5–3.5 cm long, 0.4–1.0 cm diam.; blades chartaceous to subcoriaceous, ovate to broadly elliptic, cordate to semicordate at base, acute or acuminate at apex, 18–59 × 15–37(40) cm, dark green, glossy above and bright light green below, drying light brown above and dull green below; perforations absent or present, 1–4 per side, oblong-elliptic, generally arranged in one side; margins entire; midrib sunken adaxially, prominent abaxially, primary lateral veins 5–9 per side, whitish and prominent abaxially, departing midrib at 65–70°; secondary veins parallel and joined near the medial part of the blade to the margin. INFLORESCENCES curved or rarely erect, at an angle of 40–60°, on ascending or pendent stems, arranged in the axils of the leaves or into cataphylls; peduncle green or yellowish, smooth towards the apex, with greenish-white pustules at base, 5–20 cm long, 0.8–2.0 cm diam.; spathe obtuse or mucronate, light green or yellowish green during development, white to creamy internally and green-yellowish or yellowish externally at anthesis, cucullate, coriaceous, 15–19 × 12–15 cm, marcescent after anthesis, without enveloping the spadix, up to 1 cm longer than the spadix; spadix white during development, white-creamy at anthesis, 8–16 cm long, 2–4 cm diam., with a sterile flowered slender region towards base; basal sterile flowers with a transparent stigmatic secretion, 4–6 mm long; fertile flowers 5–7 mm long; stamens 1–6 mm long, with laminar filaments; anthers 1.5–2 mm long; ovary quadrangular in longitudinal section, ribbed, 4–5 × 3.5–4.0 mm; style pyramidal and conical, 3.5–4.0 × 2.5–3.5 mm; stigma linear, with a yellowish stigmatic secretion; berries with a green stylar cap during development, mature stylar cap yellowish-green; pulp white; seeds pale yellow and brown, ovate-oblong, 6–9 × 5–7 mm; strophiole thick, yellow.

Distribution and ecology: — Monstera guzmanjacobiae is endemic to the Los Tuxtlas region of Mexico. It is known from the municipality of Catemaco between La Palma and the road between Tebanca and Miguel Hidalgo, at 400 m, in a Tropical wet forest life zone.

Phenology: —Flowering and fruiting was recorded in February, March, April, May, June and November.

Discussion: —The species is member of sect. Marcgraviopsis and is characterized by the ligule of the petiole sheath 1.5–3.0 cm in length, the adult plant’s leaf blade with fenestrations (1–4 perforations) often only on one side or lacking fenestrations, the inflorescence erect or inclined, the flowers with a conical pyramidal style, the seeds with a yellowish color and with a thick yellow strophiole.

Monstera guzmanjacobiae is similar to M. luteynii but this is endemic from Costa Rica and has non-fenestrate blades and flowers with truncate style. It could also be confused with M. tuberculata , because both have pendent habit, although the latter has leaf blades two to three times smaller, rarely fenestrate, and the inflorescences are completely pendent (inclined between 40–60° and rarely erect in M. guzmanjacobiae ). Adult plants of M. guzmanjacobiae have leaf blades similar to those of pre-adult plants of M. punctulata . However, in this latter species, the fenestrations have varied sizes and some reach the edge of the blades.

Additional specimens examined: — MEXICO. Veracruz: Municipio Catemaco, La Palma, Acahual (con elementos de selva alta perennifolia), 18º33’12’’N, 95º03’41’’W, 30 m, 20 September 2018, P. Díaz-Jiménez, et al. 1427 ( MEXU!, UJAT!); Municipio Catemaco, Tebanca, relicto de selva alta perennifolia, 18º22’13’’N, 95º00’56’’W, 361 m, 25 February 2019, P. Díaz-Jiménez & M. M. Alarcón 1429 ( XAL!) .

Figures

FIGURE 44. Monstera guzmanjacobiae from Veracruz, Mexico. (A) Developing inflorescence. (B) Infructescence with stylar caps mostly already detached. (C) Fertile flower; in lateral view (left), and in longitudinal section. (D) Adult plant showing pendent inflorescence and developing flagellum. (E) Inflorescence with open spathe, front view. (F) Inflorescence with open spathe, back view. (G) Sterile flower; lateral view (left), and longitudinal section (right). (H) Stylar plate with stigma (left) and one stamen (right). (I) Seed. (J) Seedling transforming into a juvenile shingle-leaved plant. (K) Juvenile plant. P. Diaz-Jiménez et al. 1429 (XAL). Image from Díaz-Jiménez et al. (2020).

FIGURE 45. Monstera guzmanjacobiae. Adult plant growing in the locality type in Veracruz, Mexico. P.Diaz-Jiménez et al. 1429 (XAL). Photo by M. Cedeño-Fonseca.