Northwest Congolian lowland forests

A frost-tender broadleaf evergreen tree of the laurel family, native to Mexico and Central America and grown across the tropics and subtropics for its buttery, pear-shaped fruit. Glossy dark-green elliptic leaves 4 to 8 inches long clothe a tree that reaches 30 to 60 feet, hung with greenish-yellow flower panicles that give way to large single-seeded berries. Hardy only in USDA zones 10-12 - north of that it is an indoor curiosity easily sprouted from a pit, but one that rarely fruits.

The premier true mahogany and one of the most commercially important tropical hardwoods on Earth: a very large neotropical timber tree that reaches roughly 100 to 150 feet with a broad, spreading, rounded crown, pinnately compound leaves, and reddish-brown heartwood prized for fine furniture and instruments. Honesty first: this is a knowledge and conservation entry, not a plant most people can or should grow. It is a frost-tender tropical giant hardy only in USDA zones 10b-12b, native to the neotropics from southern Mexico through Central America into Amazonian South America, with no role as a temperate-garden ornamental. More important than any landscape use is its conservation status - decades of overharvest for that famous mahogany timber have made it conservation-sensitive, and it is listed on CITES Appendix II, meaning international trade is regulated to keep harvest from driving the species toward extinction. Include it for its story and its scale, and source any wood or plant material only through legal, certified, sustainable channels.

Broadleaf plantain is the broad-leaved, ground-hugging weed of lawns, paths, driveways, and roadsides across North America - and, honestly, an introduced Eurasian species, not a native. It forms a flat basal rosette of broad, strongly ribbed oval leaves that presses tight to the ground, sending up slender, erect, rat-tail flower spikes through summer. Its tie to human disturbance runs so deep that some Indigenous peoples called it 'white man's footprint,' because it followed colonists wherever soil was trodden bare. Despite the weedy reputation it is genuinely undervalued for habitat: the wind-pollinated spikes are heavy pollen sources, the ripe seed feeds finches and other small birds, and it is a documented larval host for the common buckeye butterfly. The young leaves are edible cooked or in salad, with a long medicinal and poultice history.

Cacao is the chocolate tree - a small evergreen understory tree of the lowland tropical rainforest, famous for being cauliflorous: its tiny pink-and-white flowers, and then the large ridged football-shaped pods, are borne directly on the trunk and oldest branches rather than out among the leaves. Reaching roughly 15 to 25 feet, it carries glossy oblong leaves that flush bronze when young. Each pod holds 30-40 seeds embedded in sweet white pulp; those seeds become chocolate only after fermenting, drying, and roasting (the cacau of Brazil). It is genuinely demanding - a true tropical, needing deep humid warmth and overhead shade and failing below about 50°F - so outside the wet tropics it is a greenhouse or conservatory plant only. Its flowers are pollinated not by bees but by tiny midges.

The true Christmas cactus - the hybrid Schlumbergera x buckleyi - a long-lived epiphytic holiday cactus grown indoors almost everywhere for its arching, segmented stems and its rose-to-magenta flowers that open in mid-winter, around Christmas. It is worth getting the identity right, because most plants sold and labeled as 'Christmas cactus' are actually the Thanksgiving cactus, Schlumbergera truncata. You can tell the two apart by the edges of the flat stem segments and by when they bloom: the true Christmas cactus has rounded, scalloped segment margins and flowers a few weeks later, in mid-winter, while the Thanksgiving cactus has sharp, claw-like teeth and blooms from late fall into early winter. Unlike a desert cactus, this is a forest epiphyte that grows on tree branches in the Atlantic coastal forest of southeastern Brazil, so it wants bright indirect light, a free-draining mix, sparing water, and - to set its buds - cool nights and short days. A reassuring point that sets it apart from many houseplants: it is non-toxic to cats and dogs. One more field mark clinches it: the true Christmas cactus has rose-pink pollen and flowers that hang almost regularly (radially), where the Thanksgiving cactus has yellow pollen and asymmetric blooms held out nearly horizontally.

A warm-season member of the nightshade family (Solanaceae) - a relative of tomato, potato, and pepper - grown for its showy, glossy edible berries that range from white and green through deep purple to nearly black depending on cultivar. The plant is technically a tender herbaceous perennial but is grown as an annual vegetable across most of North America, where it demands a long, hot, frost-free season to fruit well. Drooping violet star-shaped flowers give way to the familiar pendant fruit; the leaves, flowers, stems, and roots are toxic and only the fruit is eaten.

A tropical evergreen tree from the lowland rainforests of western and central Africa, grown almost everywhere else as a dramatic indoor specimen for its huge, glossy, fiddle- (or violin-) shaped leaves with bold sunken veins. In its native habitat it becomes a 40-foot tree, but as a houseplant or patio container plant it is typically kept to a single upright 6-15 foot trunk topped with a sculptural rosette of leaves. Winter-hardy only in the frost-free subtropics (USDA zones 10-12); everywhere colder it is a houseplant. It is famously fussy: it wants bright, steady light, even moisture, warmth, and - above all - to be left in one spot, dropping leaves in protest at cold drafts, moves, or erratic watering.

The true culinary ginger - a tropical-Asian herbaceous perennial grown for its aromatic, pungent, branched rhizome rather than its rarely-seen bloom. Reed-like pseudostems carry two-ranked lanceolate leaves to 2 to 4 feet, rising from a fleshy underground rhizome that is the kitchen and apothecary spice. Hardy outdoors only in USDA zones 9-12; in cooler regions it is grown as a warm-season annual or container plant and started from a fresh grocery-store rhizome each spring.

A fast, twining annual vine from tropical America grown for the azure-blue trumpets that open at dawn and fade by afternoon, each marked with a white-to-golden-yellow star throat. Heart-shaped leaves clothe stems that climb 8 to 10 feet in a single season on any support. Showy and easy from seed, but every part - especially the seed - is poisonous if eaten, so site it away from where pets and children graze.

A tender perennial from New Guinea grown almost everywhere in North America as a warm-season annual, prized for non-stop bright bloom in part shade - and, unlike common impatiens, in considerably more sun. It mounds 6 to 24 inches tall and 1.5 to 3 feet wide, carrying large, flat, five-petaled flowers in coral, salmon, pink, red, orange, lavender, and white above bold, often bronze-tinted dark foliage. Its real selling point is honest and practical: Impatiens hawkeri is resistant to impatiens downy mildew (Plasmopara obducens), the disease that collapsed plantings of Impatiens walleriana, making it the dependable shade-to-part-sun bedding plant where the common species can no longer be trusted.

One of the most popular and forgiving foliage houseplants - an evergreen tropical perennial grown indoors for its glossy, dark-green, lance-shaped leaves and elegant white "flowers." Those flowers are not true showy blooms but a white leafy hood, the spathe, wrapped around a creamy spadix. POWO (Kew) places Spathiphyllum wallisii native to the tropical rainforests of Colombia and Venezuela; it is now grown worldwide as an indoor foliage plant. Honesty matters here. It is famously easy: it tolerates LOW light and conveniently droops when thirsty, then recovers after a watering. But every part contains insoluble calcium-oxalate crystals and is TOXIC to cats, dogs, and people if chewed, so keep it away from pets and small children. And its celebrated "air-purifying" reputation, from a 1989 NASA chamber study, is OVERSTATED - at realistic room densities the effect on indoor air quality is negligible. Grow it for its looks and easy care, not as an air purifier. RHS rates it frost-tender, H1B, a tender evergreen for shade and indoor culture under glass.

A bold tropical fig from South and Southeast Asia grown almost everywhere as a houseplant for its large, glossy, leathery, deep-green (or cream- and burgundy-variegated) paddle leaves. Honesty first: in its frost-free native habitat and outdoors in USDA zones 9-12 this is a massive strangler-type fig that can reach 50 to 100 feet with a spreading, aerial-rooting crown - but in the homes, offices, and patio containers where almost everyone grows it, it is kept a fraction of that size by pot confinement and pruning. It is easygoing in bright indirect light and forgiving of average indoor conditions; the one real catch is its milky latex sap, a mild skin, eye, and digestive irritant that also bothers latex-sensitive people. The same latex was historically tapped to make natural rubber, which is where the name comes from.

A large, spreading tropical tree from sub-Saharan Africa, famous for the enormous grey, sausage-shaped fruits that dangle on long cord-like stalks beneath its rounded crown. Honesty first: where it is hardy (USDA zones 10a-12b) it grows into a 30-60 foot evergreen-to-semi-deciduous shade tree, and at night it opens large, maroon, foul-smelling, cup-shaped flowers that are pollinated by bats. The fruits are the headline and the hazard - they can reach about 24 inches long and weigh several pounds, and a falling fruit can genuinely injure a person or dent a car, so it must never be sited over patios, walks, or parking. The raw fruit is toxic and purgative to humans; it is used only after careful processing in traditional medicine and skincare, never eaten raw. It is frost-tender and strictly a warm-climate specimen tree, not a temperate-garden plant.

A bold tropical aroid from the rainforests of southern Mexico through Panama, grown almost everywhere outside the frost-free tropics as a foliage houseplant. It is a climbing epiphyte: it sends adventitious aerial roots to scramble up tree trunks, and its huge glossy heart-shaped leaves develop the deep cuts and oval holes (fenestrations) that give it both common names. Mature plants in the tropics flower with a creamy aroid spathe and produce a cone-like fruit that is edible only when fully ripe. Indoors it rarely flowers and is prized purely for its dramatic, architectural foliage.

A clumping, multi-stemmed evergreen perennial from South Africa, grown for its unmistakable crane-head flowers - a horizontal green-and-pink spathe from which bright orange sepals and vivid blue petals emerge like the crest of an exotic bird. Bold, paddle-shaped blue-green leaves on long stalks form a 3-4 foot fountain of foliage. Winter hardy only in USDA zones 10-12 (frost-free subtropics); everywhere colder it is grown as a houseplant or summered-out container plant. It blooms reliably only from a well-established, somewhat crowded clump, so patience is the key to flowers.

The classic florists' gloxinia, a tuberous tropical perennial of the Gesneriaceae native to the Atlantic Forest of south-eastern Brazil (POWO, Kew; recorded as Brazilian-native in Flora e Funga do Brasil). It forms a low, neat rosette of soft, velvety leaves above which sit large, showy, bell-shaped flowers in rich violet, red, pink or white, often finished with a contrasting picotee edge. POWO and Flora e Funga do Brasil record Sinningia speciosa as the wild parent of the cultivated florist gloxinia, and that ornamental heritage is exactly how it is grown almost everywhere - as a tender pot or houseplant prized for its plush leaves and velvety trumpet-and-bell flowers. HONESTY: it is very frost-tender, hardy in the ground only in roughly USDA zone 11 and above, and it has a real dormant season - after flowering it dies back to a resting tuber before regrowing, so it is not an evergreen plant but a cyclical one. It is grown purely as an ornamental: no part is eaten. The flowers are insect-pollinated and, in the plant's native Brazilian range, also visited by hummingbirds.

A long-lived epiphytic cactus from the Atlantic coastal forest of southeastern Brazil, grown indoors almost everywhere for its arching, segmented stems and its showy late-fall and winter flowers in hot pink, magenta, red, orange, salmon, or white. It is the plant most often sold and labeled as a 'Christmas cactus,' but the confusion is near-universal and worth getting right: this is the Thanksgiving, crab, or claw cactus, with sharp, claw-like teeth on the edges of its flat stem segments and a bloom season that runs from late fall into winter. The true Christmas cactus is a different plant, the hybrid Schlumbergera x buckleyi, which has smooth, rounded segment margins and blooms a few weeks later. Unlike a true desert cactus, it is a forest epiphyte that grows on tree branches in dappled light, so it wants bright indirect light, a free-draining mix, sparing water, and - to set its buds - cool nights and short days. A reassuring point that sets it apart from many houseplants: it is non-toxic to cats and dogs. The surest field mark is the pollen: Schlumbergera truncata has yellow pollen and asymmetric flowers held out nearly horizontally, where the true Christmas cactus (S. x buckleyi) has rose-pink pollen and more regular, pendent blooms.