Zamioculcas

It is an herbaceous perennial growing to 45–60 centimetres (18–24 in) tall, from a stout underground, succulent rhizome. It is normally evergreen, but becomes deciduous during drought, surviving drought due to the large potato-like rhizome that stores water until rainfall resumes.

The branches are pinnate, 40–60 cm (16–24 in) long, with 6–8 pairs of leaflets 7–15 cm (3–6 in) long; they are smooth, shiny, and dark green. The stems of these pinnate leaves are thickened at the bottom. Zamioculcas zamiifolia grows slowly, reaching heights and widths ranging from 2 to 4 feet.[8]

The flowers are produced in a small, bright yellow to brown or bronze spadix 5–7 cm (2–3 in) long, partly hidden among the branch bases; flowering is from mid summer to early autumn.

Zamioculcas zamiifolia contains an unusually high water contents of leaves (91%) and petioles (95%)[15] and has an individual leaf longevity of at least six months, which may be the reason it can survive extremely well under interior low light levels for four months without water.[16]

It may survive outdoors as long as the temperature does not fall below around 15 °C (60 °F); though best growth is between 18 and 26 °C (64 and 79 °F), while high temperatures give an increase in leaf production. In temperate regions, it is grown as a houseplant. Overwatering may destroy this plant through tuber rot. Bright, indirect light is best; some sun will be tolerated.[16]

Zamioculcas zamiifolia may be propagated by leaf cuttings: typically, the lower ends of detached leaves are inserted into a moist, gritty growing medium, and the pot is enclosed in a polythene bag. Though the leaves may well decay, succulent bulb-like structures should form in the bag, and these may be potted up to produce new plants. The process may take upwards of one year. The plant can also be propagated by division.

Due to its strong green leaves, it is especially suitable for open, bright rooms.[17] When grown indoors, the plant prefers bright indirect light but will tolerate low light conditions. However, lower light is not optimal for an extended period of time. Insufficient amounts of sunlight can result in leaves lengthening and/or falling off, yellowing (chlorosis), and generally uneven or disproportionate growth as the plant stretches towards a light source.When grown outdoors, Zamioculcas zamiifolia prefers part shade to full shade.[4]

The substrate used must be well-drained and contain nutrients. It can be composed of a mixture of tanned ox manure, washed river sand and red earth (1:1:1).[18] For indoor plants, use a well-drained potting soil mix.[8]

Zamioculcas zamiifolia roots are rhizomatous and have the ability to store moisture, thus aiding the plants in their drought resistance. The plants like regular waterings, but the soil should be allowed to dry out between waterings.[4]

Though little information is available, Z. zamiifolia is apparently used medicinally in the Mulanje District of Malawi and in the East Usambara mountains of Tanzania where juice from the leaves is used to treat earache.[19]

In Tanzania, a poultice of bruised plant material from Z. zamiifolia is used as a treatment for the inflammatory condition known as "mshipa".[20]

Roots from Z. zamiifolia are used as a local application to treat ulceration by the Sukuma people in north-western Tanzania.[21]

A 2014 study from the Department of Plant and Environmental Science at the University of Copenhagen shows that, in a laboratory setting, the plant is able to remove volatile organic compounds in this order of effectiveness: benzene, toluene, ethylbenzene and xylene at a molar flux of around 0.01 mol/(m² day). The same study stated that any effectiveness on indoor environments is inconclusive.[22]

Zamioculcas zamiifolia is part of the family Araceae, which includes many poisonous genera, such as Philodendron, Monstera, Anthurium, Dieffenbachia, Aglaonema and Spathiphyllum, all of which contain insoluble calcium oxalate.

An initial toxicological experiment, conducted by the University of Bergen in 2015, on extracts from Z. zamiifolia (using brine shrimp as a lethality assay), did not indicate lethality to the shrimp, even at concentrations of extracts up to 1 mg/mL. The scientists conducting the experiment observed that, "…On the contrary, it could appear as though the extract contributed to improvements in the vitality of the larvae".[15]