MONSTERA GIGAS
PROTOLOGUE: Monstera gigas Croat, Zuluaga, M.Cedeño & O.Ortiz, published in Webbia 76: 272 (2021).
Monstera gigas Croat, Zuluaga, M.Cedeño & O.Ortiz, sp. nov. Type: Panama. Chiriquí: Fortuna Dam area, unnamed creek to E of road flowing into Río Hornito near Quebrada Moro, 1200 m, 16 Jun 1984, W.Churchill 5508 (holotype, MO-3216379–821!; isotype, PMA!).
DISTRIBUTION: Panama: Panama.
DISTRIBUTION NOTE: Panama: Chiriquí.
SPECIES DESCRIPTION:
Very robust to gigantic, pachycaulous, appressed-climbing nomadic vine or rarely terrestrial. Seedlings: bearing foliose leaves. Juvenile plants: root climbers; unknown. Adult plants: root climbers; stems pale green, smooth, cylindrical; internodes 1.5–2.0 cm long, 3–11 cm diam., 0.2–0.5 times as long as wide; anchor roots unknown; feeder roots unknown; petiole light green, white-dotted, smooth, (45)66–81(140) cm long, sheathed up to (0.36)0.74– 0.86 its total length; petiole sheath slightly persistent, drying dark brown with pale brown margins; geniculum white-dotted, 13–17 cm long, 3 cm diam.; leaf-blades narrowly ovate-elliptic, rounded on both sides, subcordate on one side and rounded on the other side, or unequal (one side 4–5 cm wider) at base, short-acuminate at apex, moderately coriaceous, (43)72–86(140) × (25)34–40(61) cm, 1.67–2.20 times longer than wide; fenestrations absent or present; margins entire; midrib weakly sunken and colorless to weakly discolored toward the distal margin, greenish white and thicker than broad abaxially, convex toward the apex, closely rounded and pale brown below; primary lateral veins (21)24–65 per side, sunken and colorless adaxially, closely narrowly rounded and pale abaxially, departing the midrib at (40°)55–75° toward the apex and 80–90° in the lower part of the blade; secondary veins parallel, moderately prominent adaxially.³
INFLORESCENCE:
Inflorescences on ascending stems; peduncle smooth, 34.0–38.5 cm long, 1.7–2.2 cm diam.; spathe acuminate, white at anthesis, coriaceous, 30–34 × 15.0–18.5 cm; spadix white at anthesis, 20.0–25.5 cm long, 3.2–4.2 cm diam.; basal sterile flowers 3–5 mm long; fertile flowers 5–6 mm long; stamens with laminar filaments; anthers 1.5–2 mm long; ovary rectangular in longitudinal section, ribbed, 4–5 × 1.5–2.5 mm; style hexagonal, 1.5–2.0 × 1.5–2.0 mm; stigma circular; berries with a white stylar cap when ripe; seeds unknown.³
ECOLOGY:
Monstera gigas is endemic to Panama where it is known only from the type locality in the region of the Fortuna Lake at 1200–1300 m, in a Premontane rain forest life zone. Fruiting has been recorded in January, April, July, and September.³
ETYMOLOGY:
The epithet is a noun in apposition, from the ancient Greek word “gígas” meaning a giant, in reference to the exceedingly large size of its leaves, the largest recorded in the genus.²
NOTES:
1. Monstera gigas is characterized by petioles with white dots, a slightly persistent sheath, sometimes enormous leaf blades subcordate at the base, with entire margins, with or without fenestrations, and 24–65 primary lateral veins per side, sunken adaxially, departing the midrib at 80–90° in the lower part of the blade and 55–75° toward the apex.²
2. The species is member of sect. Monstera characterized by its usually nomadic-vine (but sometimes terrestrial) habit, large stems with short, stout internodes, subterete, pale yellowish brown petioles sheathed to within 13–17 cm from the base (to 36 cm on preadult leaves), and ovate-elliptic, grayish-drying, entire and non-perforated, short-acuminate leaf blades, rounded at the base and with 24–65 primary lateral veins per side, as well as by its moderately short-pedunculate, massive, green-white spathes, green spadices, and flowers with a narrow style covered for nearly its entire width by the stigma, the latter bearing a tubular extension that protrudes beyond the end of its center. Leaves at the upper end of the size range for this species, exceeding 3 m in length, are the largest so far know in the genus, and the plant is perhaps the most massively constructed member of its entire subfamily.³
3. Conservation status: Monstera gigas should be considered as data deficient (DD).²
STORY:
STORY TITLE: The largest leaves in the genus
Leaves at the upper end of the range in Monstera gigas exceed 3 m in length, the largest so far known in the genus, and the plant is perhaps the most massively constructed member of its whole subfamily.² It was first collected sterile in April 1980 and assumed at the time to be new; Thomas Antonio found it fertile later the same year.² Because of its large entire leaves it then became confused with Monstera standleyana, to which it is probably closely related, until 2021, when it was separated by its shorter petiole sheath, gray-drying blades rounded at the base, and a narrow style covered almost entirely by a stigma with a tubular extension.²
It is known only from around Fortuna Lake at 1200 to 1300 m and is Data Deficient.² Its companion in the same paper, Monstera titanum, holds the other record: the largest inflorescence in the genus, peduncle and spathe together approaching a meter.²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Monstera gigas Croat, Zuluaga, M.Cedeño & O.Ortiz
2. Webbia 76: 272 (2021) — protologue.
Additional photos from iNaturalist by ramon_d