Red River freshwater swamp forests

A bold, clump-forming evergreen perennial from South Africa, grown for big rounded umbels of trumpet-shaped blue (or white) flowers held on tall bare stalks above arching, strap-shaped leaves in mid-to-late summer. It is widely sold as "lily of the Nile," but that is a misnomer - the plant is South African (the Cape provinces and KwaZulu-Natal), not from the Nile. Spectacular and easy in warm climates, this evergreen Agapanthus is frost-tender, so in cold-winter areas it is grown in a container and overwintered under cover. The RHS has given several Agapanthus praecox forms its Award of Garden Merit and rates this evergreen species half-hardy (H3 - needs winter protection).

One of the world's most spectacular flowering trees and, in the same breath, one of its most dangerous invaders. Spathodea campanulata is a large, fast-growing tropical tree native to the moist forests of West and Central Africa (GBIF), carrying a dense crown of glossy compound leaves topped by showy, upturned clusters of big, frilly, scarlet-to-orange, tulip-shaped flowers (the boat-shaped buds hold water). It is glorious - and it is a serious invasive. The African tulip tree is listed among the IUCN "100 of the world's worst invasive species"; outside its native range it has overrun wet-tropical forests across the Pacific, Hawaii, the Caribbean, and parts of Asia and Australia, and its flowers can be lethal to native bees. Plant it ONLY where it is genuinely native or where it cannot escape, and first check that it is not prohibited locally - do not plant it in any tropical region where it can naturalise. It is frost-tender (USDA 10a-11), fast, and wants full sun and moisture; in cold-winter climates it is grown only as a tender container specimen kept frost-free. It is an ornamental, not a food plant.

Hippeastrum x hybridum is a complex garden hybrid derived from six or more wild Hippeastrum species native to tropical and subtropical South America, developed through intensive breeding since the late 18th century and now the dominant "amaryllis" sold worldwide as a holiday bulb. It produces spectacular trumpet-shaped flowers - 5 to 8 inches across - on stout leafless scapes in red, pink, white, orange, salmon, or bicolour, making it one of the most dramatic winter-flowering houseplants available. The honest catch is toxicity: the entire plant, especially the bulb, contains lycorine and related alkaloids at concentrations that cause vomiting, salivation, tremors, and hypotension in pets and children, so it must be placed out of reach and handled with care.

Angel's trumpet (Brugmansia suaveolens) is a large, soft-wooded shrub or small tree hung with enormous pendulous trumpet flowers - up to 12 inches long, white aging to soft blush, and intensely fragrant in the evening and at night. Native to the Atlantic Forest of south-eastern Brazil (POWO, Kew; Flora e Funga do Brasil), it is now classified Extinct in the Wild by the IUCN and survives only in cultivation, which makes a familiar garden plant quietly remarkable. It grows fast and thirsty in warmth (USDA zones 9b-11b) and is frost-tender, so in cold-winter areas it is grown in a large container and overwintered under cover. The load-bearing warning is its toxicity: EVERY PART IS HIGHLY TOXIC, loaded with tropane alkaloids (scopolamine, atropine, hyoscyamine), and poisonings can be severe or fatal - never plant it where children or pets could reach it.

A tender perennial from Madagascar grown across temperate North America as a heat-loving summer annual - a mounding 6-18 inch plant in the dogbane family covered in flat five-lobed phlox-like flowers from June to frost. The species blooms rosy-pink to red with a darker mauve throat, and it shrugs off the hot, humid weather that wilts most bedding plants. Every part of the plant is poisonous: it is the natural source of the vinca alkaloids used in chemotherapy.

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.

A giant herbaceous perennial from Southeast Asia and the principal wild ancestor of most cultivated dessert bananas. What looks like a trunk is a 'pseudostem' - tightly rolled leaf sheaths - topped by a fountain of huge, paddle-shaped leaves that can run 6 to 10 feet long, giving an instant tropical effect. In frost-free climates (USDA zones 10a-11b) an established clump produces a drooping flower spike and a hanging bunch of edible fruit, then that pseudostem dies and is replaced by a sucker from the base. It is frost-tender: everywhere colder it is grown as a bold container or greenhouse foliage plant that is overwintered indoors and rarely, if ever, fruits.

Gerbera jamesonii, the Barberton daisy (also Transvaal daisy), is a tufted evergreen perennial herb in the daisy family (Asteraceae) native to the summer-rainfall grasslands and rocky woodland of north-eastern South Africa and Eswatini. It forms a basal rosette of lobed leaves from which leafless flowering scapes rise, each topped by a single large daisy-style flowerhead in orange-red, yellow, pink, or white. It is the wild ancestor of the thousands of florist gerbera cultivars and earns its place as a long-blooming focal point in borders and patio containers, attractive to bees and other insects. The load-bearing caution is frost-tenderness: RHS rates it H1C, meaning it survives outdoors only in summer or the very mildest, frost-free spots and must be overwintered under glass elsewhere (roughly USDA 9-11). It is non-toxic, with no reported poisoning hazard to people or pets, making it a safe choice where toxicity is a concern.

A woody, deciduous flowering shrub in the Hydrangeaceae, native to Japan, China, Korea, and Southeast Asia and long grown as the classic "hortensia" or French hydrangea. NC State Extension describes a rounded shrub 3 to 6 feet tall and wide with large opposite, simple, toothed leaves (4 to 8 inches long) and big rounded mop-head or flat lacecap flower clusters in late spring and summer in white, pink, blue, or purple. Famously, flower color tracks soil chemistry - acidic soils push the blooms blue and alkaline soils turn them pink. It wants protection from hot afternoon sun and steady moisture, making it a mainstay of shaded foundation plantings and woodland borders.

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.

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.

Scadoxus multiflorus, the blood lily (also fireball lily, ball lily, powderpuff lily), is a summer-growing bulbous geophyte in the Amaryllidaceae, native across tropical and southern Africa to the southwestern Arabian Peninsula. Each bulb sends up a leafless stem topped by a dramatic globe-shaped umbel of scarlet flowers with protruding stamens, often before or alongside the foliage. It is a focal-point container and bedding bulb prized for its bold flower head, but it is decidedly tender - RHS rates it H1B (minimum 50 to 59°F), so outside roughly USDA zones 9b–11 it must be grown under glass or as a houseplant and dried off / overwintered frost-free. CRITICAL CAUTION: every part is toxic - Scadoxus contains poisonous alkaloids and has been used as a component of arrow and fishing poisons; the bulbs are ornamental, not edible, and the plant is harmful to people, pets, and grazing animals if ingested. Handle with gloves and keep away from children and animals.

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.

Buddhist pine (Podocarpus macrophyllus) is a slow-growing evergreen conifer native to southern Japan, southern and eastern China, Taiwan, and northern Myanmar, long prized in East Asian gardens and feng shui traditions. In mild climates it makes a handsome, dense column of strap-like dark-green foliage suitable for hedging, topiary, or a statement specimen; it also tolerates container culture well. The honest catch is its frost-tenderness: plants are reliable only from zone 7b (about 10°F) southward, and a late cold snap in zone 7 can kill established specimens to the ground. Layered on that is its pace - growth is genuinely slow, so a screening hedge planted today may take 15-20 years to reach useful height.

Cordyline australis is a dramatic, palm-like evergreen tree native to New Zealand, where it ranges from North Cape to the southern South Island. In warm-temperate gardens (USDA zones 8-11) it makes an unmistakable structural focal point with its stout trunk, arching sword-leaf crown, and spectacular fragrant flower panicles in late spring. The honest catch is its scale and tenderness: it can exceed 33 feet in mild climates, its fibrous roots are expansive and difficult to remove, a single hard frost below about 23°F can kill or badly damage an established specimen, and the saponin-bearing foliage is toxic to cats and dogs - making it a gamble outside sheltered coastal or urban sites in colder zone-8 gardens.

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.

A warm-season annual vine in the cucumber family grown for its sweet, aromatic netted melons - one of the six broadly accepted edible groups of the polymorphic Cucumis melo. Stiff-haired, rough-textured trailing stems climb 6 to 9 feet with the help of unbranched tendrils, carrying funnel-shaped yellow flowers that draw bees. Native to the Old World (Africa, the Arabian Peninsula, India, New Guinea, and Australia) and intolerant of frost, it is grown as an annual on the ground or on cages and trellises.

Cape honeysuckle (Tecomaria capensis, Bignoniaceae) is a vigorous, evergreen scrambling shrub from southern and south-central Africa, valued for tubular orange-to-apricot flowers borne erratically across much of the year. It reaches about 6.6 to 9.8 feet tall and wide as a free-standing shrub, or can be trained much taller on a trellis or wall, and is widely used for informal hedging and as a hot-color border or container plant. It is frost-tender (RHS H1C; roughly USDA 9b-11) - in cooler climates it is grown under glass or as a summer container plant and overwintered indoors. In frost-free, mild climates it can become weedy: it has naturalised and is treated as invasive in parts of Australia and on islands such as the Azores, so site it where suckering and self-layering can be managed. It is not a recognised edible and is not flagged as notably toxic, though several plant parts feature in traditional southern-African medicine; treat it as ornamental rather than for consumption. Note the accepted binomial here is Tecomaria capensis (POWO/GBIF); the widely-seen Tecoma capensis is a synonym.

A vigorous, scrambling, semi-climbing tender shrub that flowers almost without pause through the warm months, carrying broad clusters of soft sky-blue (or, in the white form, pure white) phlox-like flowers. Known as the Cape plumbago or Cape leadwort, it is native to South Africa (POWO, Kew) and is grown worldwide as an easy, long-flowering ornamental. The honest catch is its frost-tenderness: it is hardy only in USDA zones 9a-11, so in cold climates it is grown as a conservatory or large-container plant, or treated as a summer annual. Left to its own devices it climbs or sprawls 6 to 10 feet and needs support, or hard pruning, to keep its shape; the flower calyces are sticky and glandular and cling to clothing and animal fur (its own seed-dispersal trick), and it suckers. In return it is one of the best blue-flowered butterfly plants for a warm garden.

A fast-growing tropical woody shrub grown for its swollen, starchy storage roots - cassava, the mandioca of Brazil and one of the great staple foods of the tropical world. POWO (Kew) and Flora e Funga do Brasil record Manihot esculenta as native to and first domesticated in Brazil and the southern Amazon, the homeland of mandioca, manioc and tapioca. It forms a slender, upright shrub of palmately-lobed leaves on often red-tinged, jointed stems, and below ground it swells a cluster of long tuberous roots that are harvested, peeled and cooked. HONESTY (load-bearing): cassava is one of the most important food crops of the tropics, but the raw roots AND leaves contain cyanogenic glycosides (linamarin) and are TOXIC if eaten raw or under-processed - they must be peeled and properly cooked, and bitter varieties soaked and/or fermented, to drive off the cyanide before they are safe to eat. It is frost-tender (roughly USDA zone 9b and up) and drought-tolerant once established, which is exactly why it is such a dependable famine-insurance crop across the warm tropics.

A tender tropical evergreen shrub grown for its enormous, flamboyant flowers - broad funnels of red, pink, orange, yellow, or white, single or double, each with a long protruding column of fused stamens. Native to tropical Asia (a cultigen of such ancient cultivation that no certain wild origin survives), Hibiscus rosa-sinensis blooms continuously in warmth above glossy, dark green, evergreen leaves. Each flower typically lasts only a day, but a healthy plant opens fresh blooms in steady succession from spring through fall - and year-round in frost-free climates. It is the classic hibiscus of warm-climate landscapes and patio containers: heat- and humidity-loving, frost-tender, and hardy in the ground only in USDA zones 9a-11b.

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 deciduous small tree or large shrub from subtropical southern South America, prized for dramatic arching sprays of waxy, deep-red pea-flowers across the warm season. POWO (Kew) and Flora e Funga do Brasil record it as native to southern Brazil, Uruguay, Paraguay and northern Argentina, where it is the national flower of both Argentina and Uruguay (the ceibo / corticeira). Tough and frost-hardy to the roots, it resprouts after a light freeze and tolerates wet ground. The seeds and bark contain toxic erythrina alkaloids, so no part should be eaten.

A tender tropical foliage plant grown for its boldly patterned, toothed leaves rather than its flowers - magenta, maroon, lime, and copper combinations in almost every color of the spectrum except true blue. A frost-sensitive perennial native to tropical and subtropical Asia and northern Australia, it is grown almost everywhere outside USDA zones 10-11 as a warm-season annual, container plant, or houseplant. The small blue-to-white nettle-like flower spikes are insignificant and are usually pinched off to keep the plant compact and the foliage at its best.