<P> A houseplant is a plant that is grown indoors in places such as residences and offices . Houseplants are commonly grown for decorative purposes, but studies have also shown them to have positive psychological effects . Houseplants also help with indoor air purification . Plants used in this fashion are most commonly, though not always, tropical or semi-tropical epiphytes, succulents or cacti . </P> <P> Houseplants need the correct moisture, light levels, soil mixture, temperature, and humidity . As well, houseplants need the proper fertilizer and correct - sized pots . </P> <Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (May 2013) (Learn how and when to remove this template message) </Td> </Tr> </Table>

What characteristics allow for some plants to grow indoors
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