Swiss cheese plant (Monstera deliciosa, Liebm. 1849)

Identity

The Swiss cheese plant (Monstera deliciosa Liebm., published in 1849), also called split-leaf philodendron, is a perennial in the genus Monstera and family Araceae. The latter name preserves both earlier classifications under Philodendron and persistent horticultural usage; the species is now placed in Monstera. ^{2 10 11}

Ceriman may name the plant or its fruit. Fruit-salad plant is another English name, and the fruit explains deliciosa. Names in other languages remain names in those languages rather than English synonyms. ^{4 5 10}

Identification

Monstera deliciosa is a robust hemiepiphytic climber. Its nodes produce aerial roots that anchor the plant to a trunk or other support. Wild stems reach about 20 m (66 ft) or more; indoors, plants generally remain 1.8–2.4 m (6–8 ft). These figures describe different contexts, not one height range. ^{5 14 12}

Young leaves are small and entire. Mature leaves become larger, leathery, glossy, heart-shaped, deeply split and sometimes fenestrated. Mature leaves measure 60–90 cm (24–35 in) and can reach about 1 m (3.3 ft). A plant without holes may therefore be young or may not yet have developed its adult foliage. ^{4 5 14 13}

The visible “flower” is an aroid inflorescence: a central spadix in a creamy white spathe. It becomes an upright green infructescence covered in polygonal scales. ⁵

Useful taxonomy

Current botanical synonymy assigns these selected names to the species:

• Monstera borsigiana K.Koch
• Monstera deliciosa var. borsigiana (K.Koch) Engl.
• Monstera deliciosa var. sierrana G.S.Bunting
• Monstera lennea K.Koch
• Philodendron anatomicum Morsch
• Philodendron fenestratum Linden
• Philodendron pertusum Kunth & C.D.Bouché
• Tornelia fragrans Gutierrez ex Schott, an illegitimate homotypic name

Borsigiana appears both in synonymy and trade. Monstera tacanaensis, formerly associated with M. deliciosa, is now accepted as distinct; a 2020 taxonomic comparison explains the separation. The stable reference is Monstera deliciosa. ^{2 15 16}

Habitat and range

Under the current taxonomic circumscription, the native range is southern Mexico, including Veracruz, Oaxaca and Chiapas, to Guatemala. Older horticultural accounts extend it to Panama, partly reflecting the taxonomic history of M. tacanaensis. Costa Rica, Honduras, Nicaragua and Seychelles are recorded as areas of introduction. ^{2 15 16}

The seeds germinate on the ground, and seedlings move toward darkness until they find and climb a tree. An often-cited experiment demonstrated this skototropism in Monstera gigantea, a different species, so it illustrates the mechanism but was not conducted on M. deliciosa. The plant uses the tree as support rather than parasitizing it. ^{4 9}

The species is naturalized in warm parts of eastern Australia and listed as an environmental weed in parts of New South Wales. That regional status does not establish a universal invasive classification or a regulatory status in France. ⁸

Life cycle and reproduction

The seasonal guidance concerns indoor cultivation in metropolitan France in the Northern Hemisphere. It gives relative trends, not universal measured needs. Feeding from April to September reflects a British growing context; elsewhere, timing follows active growth and conditions. ¹

Flowering is uncommon indoors but normal on a mature plant in a suitable climate. A creamy spathe surrounds the spadix, where the fruit develops. ^{4 5}

The ceriman is described as 20–25 cm (8–10 in) long and about 6 cm (2.4 in) wide, while fruit-growing references give a broader 20–36 by 5–9 cm (8–14 by 2–3.5 in) range. It ripens in 12–14 months. Scales and flesh should release naturally; even ripe fruit may irritate sensitive people, and large amounts are discouraged. Flavor comparisons include pineapple, banana and mango. ^{5 4 13}

Propagation is mainly by stem cuttings or air layering. Stem sections need nodes, where buds for new growth occur. ^{3 4 5}

Uses and risks

The main use is ornamental. In tropical or subtropical climates it may climb a tree, shaded wall or sturdy trellis; in temperate climates it is usually kept indoors in bright light. Support encourages its natural habit and often larger leaves. ^{3 5}

Leaves, stems, sap and unripe fruit contain insoluble calcium oxalate crystals. Chewing can cause oral irritation, drooling, vomiting and difficulty swallowing. Toxicity is established for cats and dogs, also reported for horses, and described as low in humans, chiefly after substantial ingestion or sap contact. No particular susceptibility has been established for children; keeping them away from the plant remains an exposure precaution. For other animal species, the risk remains unknown. ^{6 7 12}

Varieties, look-alikes and related plants

Variegated forms are not separate species. The horticultural names Variegata, Albovariegata and Marmorata are attested, while the edibility and fruit quality of some variegated forms remain unestablished. For Aurea, Thai Constellation, Mint and Taureri, the traits described in commerce, their rarity and the stability of their variegation remain uncertain. ¹³

Monstera adansonii is a smaller plant. In these climbing plants, support encourages larger, perforated leaves. A young M. deliciosa may therefore lack the deeply divided appearance of an adult specimen; the absence of holes alone is not enough for identification. ¹

Main sources

• RHS, How to grow Swiss cheese plants
• Plants of the World Online / Kew, Monstera deliciosa Liebm.
• Royal Horticultural Society, Monstera deliciosa
• University of Wisconsin Extension, Monstera deliciosa
• Monaco Nature Encyclopedia, Monstera deliciosa
• ASPCA, Monstera deliciosa toxicity entry
• Merck Veterinary Manual, insoluble calcium oxalates
• Environmental Weeds of Australia, Monstera deliciosa
• Strong & Ray, 1975, skototropism in Monstera gigantea
• French National Museum of Natural History, Monstera deliciosa
• Metz Botanical Garden, educational inventory
• NC State Extension, Monstera deliciosa
• University of Florida IFAS Extension, Monstera deliciosa
• Oxford University Herbaria, Monstera deliciosa
• Plants of the World Online / Kew, Monstera tacanaensis
• Cedeño-Fonseca et al., taxonomic comparison