Which tree has purple flowers? Check the month, then the leaves

Spring, before the leaves: redbud, saucer magnolia, paulownia, lilac

Eastern redbud is the purple haze along woodland edges in March and April. The NC State profile describes pea-shaped flowers only about half an inch wide, roughly 7 to a cluster, pink to red to purple, that open before the leaves and grow on new stems as well as older branches, often straight out of the trunk. That habit answers "tree with purple flowers on the trunk" and "on the bark". The heart-shaped leaves, 3 to 5 inches across, arrive after the bloom. NC State gives the native range as New Mexico north to Nebraska, east to Michigan and Ontario, and south to Florida. The redbud page covers it in full.

Saucer magnolia is the one with flowers the size of a teacup. NC State's saucer magnolia profile gives cup-shaped flowers 4.7 to 10 inches across, with tepals pink-purple on the outside and white inside, on bare branches in mid-spring. It is a hybrid, 15 to 33 feet tall, with smooth gray bark, and NC State warns that late frosts can kill its early flowers. Other magnolias are on the magnolia page.

Royal paulownia (princess tree, empress tree) blooms a little later on a much bigger, coarser tree. The NC State profile describes upright clusters up to 14 inches long of funnel-shaped flowers 1.5 to 2 inches long, pale violet to pink with dark spots and yellow stripes, vanilla-scented and resembling foxglove. Its leaves are opposite, heart-shaped and 5 to 12 inches long, velvety on both sides, so the tree is easy to mistake for a catalpa once the flowers drop. NC State notes it is listed as an invasive species by the NC Invasive Plant Council, the North Carolina Forest Service and the USDA National Invasive Species Information Center; it seeds freely along roadsides and resprouts from the roots when cut.

Common lilac is usually a large shrub, 8 to 16 feet tall according to NC State's lilac profile, but old ones are trained into small trees. Look for cone-shaped clusters up to 8 inches long of highly fragrant, four-lobed tubular flowers and opposite, heart-shaped leaves.

Summer bloomers: crape myrtle, chaste tree, desert willow

If the tree is in full purple bloom in July, rule out everything above.

Crape myrtle is the summer default across the South. According to the NC State profile, it flowers from July to September in panicles 6 to 18 inches long; each flower is 1 to 1.5 inches wide, usually with six crinkled petals that look like crepe paper. Cultivars come in white, pink, red and purple. Confirm with the bark: thin, smooth, pale brown to gray, and peeling. The small leaves (1 to 2.75 inches) are mostly opposite, sometimes in threes.

Chaste tree (vitex, lilac chastetree) has narrow spikes rather than round clusters. NC State describes fragrant lavender, pink or white flowers in loose panicles up to 12 inches long that bloom all summer, and compound leaves with 5 to 9 lance-shaped leaflets spreading like fingers, grayish beneath, with a menthol smell when bruised. Small purple fruits about 3 to 4 millimeters follow. NC State notes it reseeds freely and has the potential to become invasive, especially in the South.

Desert willow is not a willow; its leaves just look like one. Texas A&M Forest Service's Trees of Texas describes linear leaves 4 to 12 inches long and only half an inch wide, tubular lavender or white flowers 1 to 1.5 inches long in summer or after a rainstorm, and slender pods 7 to 12 inches long like a catalpa's. It grows wild in West Texas on dry, gravelly soils and dry stream channels.

Texas and the Southwest

Texas mountain laurel, also called mescalbean, is the purple tree of Texas in early spring. Texas A&M Forest Service's entry describes a dense cluster of purple, pea-like flowers that opens with the new leaves and smells like grape-flavored drink, on an evergreen shrub or small tree to 20 feet with glossy compound leaves of 5 to 9 leaflets. It grows on limestone soils in Central, South and West Texas. Its hard brown pods, 2 to 5 inches long, hold 3 to 8 red seeds. Texas A&M Forest Service states the seeds are highly poisonous to humans, and NC State's Plant Toolbox lists the seeds as the poisonous part.

Mexican redbud grows in the canyons of extreme southwest Texas and is planted for hot, dry sites. Texas A&M Forest Service's Mexican redbud entry gives purple to pink pea flowers before the leaves and small, glossy, heart-shaped leaves 1 to 2.5 inches across with a wavy edge; the Texas redbud has larger leaves without the wavy edge. Desert willow, chaste tree and crape myrtle, above, complete the Texas summer list.

Florida and California: jacaranda and orchid tree

Jacaranda is the purple street tree of frost-light climates. UF/IFAS's fact sheet describes lavender-blue, trumpet-shaped flowers on 12- to 18-inch panicles that can appear any time from April to August, most often in May, sometimes before the new leaves. The leaves are fern-like and twice divided, 9 to 18 inches long with leaflets only a quarter inch long, and the fruit is a round, flat, woody disk about 3 inches across. It grows in USDA zones 9B to 11, and NC State's jacaranda profile lists it as cultivated in Florida, Texas and California, where fallen flowers carpet the ground under it. UF/IFAS does not consider jacaranda a problem species in Florida.

Orchid tree is the other purple tree of south and central Florida. The UF/IFAS Plant Directory describes large, fragrant, orchid-like flowers, pale magenta to indigo and occasionally white, with dark red and yellow on the upper petal, above rounded leaves split into two lobes, then flat pods up to a foot long. UF/IFAS's fact sheet gives flowers 3 to 5 inches wide from January to April. The Plant Directory lists it as a Category 1 invasive species on the Florida Invasive Species Council list, and the UF/IFAS assessment rates it invasive and not recommended in south Florida, a caution species in central Florida and not a problem in north Florida.

Purple flowers and green fruit

The pods and capsules that follow the flowers settle many cases in early summer. Royal paulownia sets woody, oval capsules 1 to 1.5 inches long that are sticky and green at first and turn brown in fall, splitting to release thousands of tiny winged seeds (NC State). Redbud hangs flat pods 2 to 4 inches long, green turning brown, with about 9 seeds each. Desert willow hangs pods 7 to 12 inches long and very slender. Jacaranda makes round, flat disks, and chaste tree small, dry purple fruits. Texas mountain laurel's pods are hard and brown, with red seeds.

How to tell them apart in the field

1. Look at the leaves, or their absence. None yet: redbud, saucer magnolia, often jacaranda. Fern-like: jacaranda. Two-lobed: orchid tree. Huge and velvety: paulownia. Finger-like leaflets: chaste tree. Long and narrow: desert willow. Evergreen and glossy: Texas mountain laurel.
2. Look at one flower. Pea-shaped: redbud or Texas mountain laurel. Big cup: saucer magnolia. Foxglove-like trumpet: paulownia, jacaranda or desert willow. Crinkled petals: crape myrtle.
3. Smell it. Grape drink: Texas mountain laurel. Vanilla: paulownia. Strong perfume on a shrub-sized plant: lilac.
4. Check the bark. Smooth and peeling in patches: crape myrtle.

If the flowers lean pink rather than purple, go to trees with pink flowers; for white bloomers, see trees with white flowers.

A photo while it is in bloom

Purple bloom lasts a couple of weeks at most, so photograph it now, with a few leaves in the frame. Tree Identifier names a tree from one photo of the flowers, the leaves or the whole tree; eastern redbud, royal paulownia, jacaranda and crape myrtle are in its Collection. Tree Identifier shows no confidence score, so check the answer against the leaf and flower clues above, and use the follow-up chat for questions such as how a paulownia differs from a catalpa. Its Toxicology notes are AI-written; for anything about seeds or pods, ask a local expert.