# Araceae
**Araceae**, the arum family, is a family of monocot flowering plants whose flowers are borne on a fleshy spike (the spadix) usually subtended by a single bract (the spathe). It is a large and ancient family, established as a family in 1789 by Antoine Laurent de Jussieu, with about 144 genera and roughly 3,650 to 4,000 species distributed pantropically and in most other regions.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) • [2](https://www.sciencedirect.com/science/article/pii/S1055790314000682) The family shows exceptional morphological diversity, containing the smallest known angiosperm and some of the largest vegetative and reproductive structures in the world.[2](https://www.sciencedirect.com/science/article/pii/S1055790314000682)
| Key fact | Detail |
|---|---|
| Family name | Araceae Juss., first published in *Genera Plantarum* (Paris) in 1789; accepted family[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) |
| Size | 144 genera, c. 3,650 species (pantropical and in most other areas); another Kew treatment gives ca. 4,000 species worldwide[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) |
| Placement | Order Alismatales, together with families such as Alismataceae and Potamogetonaceae[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) |
| Signature inflorescence | Unbranched spadix of minute flowers subtended by a single spathe; fruit usually a berry[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) |
| Duckweeds included | Lemnaceae Gray is treated as a synonym; the free-floating Lemnoideae are part of Araceae[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) |
| Fossil record | Known in the fossil record from the early Cretaceous, one of the oldest among angiosperm families[3](https://bsapubs.onlinelibrary.wiley.com/doi/full/10.3732/ajb.1000158) • [4](https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2012.04220.x) |
| Major food crops | Taro (*Colocasia esculenta*) and tannia (*Xanthosoma sagittifolium*) are the most important edible aroids[5](https://www.fao.org/4/X5415E/x5415e01.htm) |
## Morphology
Araceae are perennial herbs, terrestrial, epiphytic, aquatic, or free-floating, sometimes gigantic, climbing, or seasonally dormant geophytes with tubers or thickened rhizomes.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) The leaves are alternate and petiolate, usually divided into a blade, petiole, and petiole sheath, and are extremely variable in shape, from entire to deeply lobed or compound, often variegated, with reticulate or parallel-pinnate venation.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) [Calcium oxalate](https://www.edgepedia.org/calcium-oxalate) raphides are always present, and laticifers are common in the family's anatomy.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information)
**The inflorescence** defines the family. It consists of a spadix, a dense unbranched spike of minute, sessile flowers, subtended by a spathe, a solitary specialized bract that may be green, white, or otherwise colored; no other bracts are present.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) The flowers are bisexual or, more commonly, unisexual, with the female (pistillate) flowers toward the base of the spadix and the male (staminate) flowers above; sterile flowers of varying shape often separate the fertile zones, and the spadix apex sometimes forms a sterile appendix.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) The fruit is usually a berry with one to many seeds.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information)
In the duckweed subfamily [Lemnoideae](https://www.edgepedia.org/lemnoideae), the plants are reduced to minute floating bodies, and the inflorescence is hidden within a minute dorsal cavity of the plant body (as in *Wolffia* and *Wolffiella*) or in paired lateral budding pouches (as in *Spirodela*, *Landoltia*, and *[Lemna](https://www.edgepedia.org/lemna)*); these plants flower very rarely.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information)
## Classification and phylogeny
Araceae is placed in the order [Alismatales](https://www.edgepedia.org/alismatales) in the Angiosperm Phylogeny Group classification, together with families such as [Alismataceae](https://www.edgepedia.org/alismataceae) and [Potamogetonaceae](https://www.edgepedia.org/potamogetonaceae).[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) • [6](https://onlinelibrary.wiley.com/doi/10.1111/boj.12385) Detailed classification of the family began in the nineteenth century with the work of Heinrich Wilhelm Schott (1794–1865) and Adolf Gustav Engler (1844–1930).[2](https://www.sciencedirect.com/science/article/pii/S1055790314000682)
**Molecular phylogenetics** has reshaped the family's internal classification. A 2014 phylogenomic study used Illumina sequencing and reference-based assembly to resolve remaining questions in the deep phylogeny, sampling 32 genera and obtaining 7 more from GenBank, representing 42 of the 44 major clades described by Cusimano and colleagues in 2011, and tested congruence between plastid and mitochondrial data.[7](https://pubmed.ncbi.nlm.nih.gov/24594061/) Later target-sequence work confirmed the phylogenetic position of the enigmatic genus *Calla* and supported an expanded delimitation of subfamily Aroideae that includes this bisexual-flowered genus, a sounder basis for studying the evolution of the syndrome combining unisexual flowers, highly adapted spathes, zoned spadices, and inaperturate pollen.[8](https://bsapubs.onlinelibrary.wiley.com/doi/10.1002/ajb2.16117)
## Fossil record and biogeography
Araceae is a monocot group known in the fossil record from the early [Cretaceous](https://www.edgepedia.org/cretaceous), giving it one of the oldest fossil records among angiosperm families.[3](https://bsapubs.onlinelibrary.wiley.com/doi/full/10.3732/ajb.1000158) • [4](https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2012.04220.x) A 2012 genus-level phylogeny was used to infer the family's global history with models accounting for past continental positions and fossil-based range data, addressing when and where the family underwent its early diversification and the timing of the evolution of its two aquatic lineages, *Pistia* and Lemnoideae.[4](https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2012.04220.x)
## Thermogenesis and pollination
Many aroid inflorescences can raise their temperature considerably above ambient during thermogenesis, a process driven by the alternative oxidase in plant respiration; the heat may volatilize malodorous compounds or maintain a warm environment in the flower, attracting insect pollinators.[9](https://www.sciencedirect.com/science/article/pii/S0005272808000881) Among thermogenic plants, Araceae are the most studied, yielding data over a broad range of flower sizes.[10](https://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2010.02190.x) [Thermogenesis](https://www.edgepedia.org/thermogenesis) occurs in only three monocotyledonous families, Araceae, Arecaceae, and Cyclanthaceae, and within Araceae it evolved independently at least six times.[11](https://pmc.ncbi.nlm.nih.gov/articles/PMC3219497/) • [12](https://www.annualreviews.org/docserver/fulltext/ecolsys/48/1/annurev-ecolsys-110316-023039.pdf?accname=guest&checksum=FEE3E7A33F9DAEE60DCE34DB2540680A&expires=1780719512&id=id)
## Uses
**Food.** The most important food crops in the family are taro (*Colocasia esculenta*) and tannia (*[Xanthosoma sagittifolium](https://www.edgepedia.org/xanthosoma-sagittifolium)*), starchy corms and tubers grown across tropical and subtropical countries.[5](https://www.fao.org/4/X5415E/x5415e01.htm) Other edible aroids include giant taro (*Alocasia macrorrhiza*), swamp taro (*Cyrtosperma chamissonis*), and elephant foot yam (*Amorphophallus campanulatus*); in the Philippines the major aroids are grown largely for food, while minor aroids are planted as surety crops in calamity-prone areas.[13](https://agris.fao.org/search/en/records/647230562c1d629bc978aa46) Kew also lists starchy edible tubers in *Xanthosoma*, *Colocasia* (taro and cocoyams), and *Amorphophallus* (including *A. konjac* and *A. paeoniifolius*).[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information)
**Ornamentals.** Aroids are widely used as ornamental plants worldwide, both as house plants and garden plants, especially in the tropics.[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information) Commonly cultivated ornamentals include *Caladium bicolor*, with spotted or variegated leaves, and *Dieffenbachia maculata*, the dumb cane; large tropical genera include *Anthurium* and *Philodendron* in the Neotropics and *[Arisaema](https://www.edgepedia.org/arisaema)* and *Amorphophallus* in the [Old World](https://www.edgepedia.org/old-world).[1](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information)
## References
1. [Araceae Juss., Plants of the World Online, Royal Botanic Gardens, Kew](https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A30000216-2/general-information)
2. [Henriques et al. (2014). Phylogenomics of the plant family Araceae. Molecular Phylogenetics and Evolution 75: 91–102.](https://www.sciencedirect.com/science/article/pii/S1055790314000682)
3. [Cusimano et al. (2011). American Journal of Botany.](https://bsapubs.onlinelibrary.wiley.com/doi/full/10.3732/ajb.1000158)
4. [Nauheimer et al. (2012). Global history of the ancient monocot family Araceae. New Phytologist.](https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2012.04220.x)
5. [FAO. Chapter 1 – Introduction, edible aroids.](https://www.fao.org/4/X5415E/x5415e01.htm)
6. [APG IV (2016). An update of the Angiosperm Phylogeny Group classification. Botanical Journal of the Linnean Society 181: 1–20.](https://onlinelibrary.wiley.com/doi/10.1111/boj.12385)
7. [Henriques et al. (2014). Phylogenomics of the plant family Araceae. PubMed.](https://pubmed.ncbi.nlm.nih.gov/24594061/)
8. [Target sequence data shed new light on the infrafamilial classification of Araceae. American Journal of Botany.](https://bsapubs.onlinelibrary.wiley.com/doi/10.1002/ajb2.16117)
9. [Regulation of thermogenesis in flowering Araceae: the role of the alternative oxidase. Biochimica et Biophysica Acta.](https://www.sciencedirect.com/science/article/pii/S0005272808000881)
10. [Seymour (2010). Scaling of heat production by thermogenic flowers. Plant, Cell & Environment.](https://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2010.02190.x)
11. [Twenty-five years of progress in understanding pollination mechanisms in palms (Arecaceae).](https://pmc.ncbi.nlm.nih.gov/articles/PMC3219497/)
12. [Annual Review of Ecology, Evolution, and Systematics 48 (2017).](https://www.annualreviews.org/docserver/fulltext/ecolsys/48/1/annurev-ecolsys-110316-023039.pdf?accname=guest&checksum=FEE3E7A33F9DAEE60DCE34DB2540680A&expires=1780719512&id=id)
13. [Ethnobotanical survey of edible aroids in the Philippines. AGRIS/FAO.](https://agris.fao.org/search/en/records/647230562c1d629bc978aa46)
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*Topic: Encyclopedia › Life and health › Plants and algae › Seed plants › Monocots › Sedges and other monocot families › Araceae (arum family)*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license