See references

Plants perennial herbs, terrestrial, epiphytic, or aquatic, most species clearly differentiated in stems, leaves, and inflorescences, some reduced to flat to globose bodies less than 5 mm in diameter, producing roots but not differentiated into stems and leaves (subf. Lemnoideae).  Leaves absent (Lemnoideae) or present; if absent, plants usually reproducing by vegetative budding; if present, leaves 1-many, alternate, petiolate; petioles often with distinct basal sheaths; blades simple or variously lobed, venation pinnate, pedate, or merely parallel. Inflorescences pedunculate fleshy spadices (spikes), spadices usually subtended by a bract-like spathe and usually bearing numerous flowers, in Lemnoideae inflorescences in reproductive pouches and with 2-3 flowers; spadices usually with flowers bisexual or all flowers unisexual, female flowers on the lower portion and male flowers above, sterile flowers often present, sometimes the top of the spadices forming a sterile appendage, in Lemnoideae)  spadices with 1 female or bisexual flower and 1-2 male flowers. Flowers minute, sessile, without bracts; tepals 0 or 4-9, free or united, sometimes forming a cup-like perianth; stamens free or united; anthers sessile or with filaments, opening by lateral or apical slits or pores; ovaries usually superior, 1-many-celled, , each cell with 1-many ovules; styles absent or short, conical. Fruits 1-many-seeded berries; seeds minute to large, with or without endosperm. 

The family Araceae is now interpreted as including, as the subfamily Lemnoideae. what used to be treated as a separate family, Lemnaceae. Members of the Lemnoideae are easy to recognize because of their combination of minute size and floating or submerged habit. The combination of the two makes the family description difficult to read, but the close relationships of the Lemnoid taxa to other Aroids has been recognized for a long time, based on their morphological and anatomical similarities. Phylogenetic research based on DNA sequences confirmed the close relationship and shows Araceae as having eight subfamilies. For more information see Wikipedia articles on Araceae and Lemnoideae.

Key to the Araceae of Somaliland and Somalia. 

References

Ittencaah, S., W.Lobin, & M. Thulin et al. (1995) Araceae in M. Thulin (Ed.) Flora of Somalia 4: 20-23. Royal Botanic Gardens, Kew, Richmond, Surrey, UK.

Stevens, P. F. (2001+). Angiosperm Phylogeny Website. Version 14, July 2017. Accessed December 6, 2021

Thulin, M. (1995) Lemnaceae in M. Thulin (ed.) Flora of Somalia 4:23-24. Royal Botanic Gardens, Kew, Richmond, Surrey, UK.

Wikipedia (2021) Araceae and Lemnoideae. Accessed 6 December 2021.

Global distribution of Araceae, including Lemnaceae, from GBIF.

Note: Some of the records may be from cultivated plants.