Pterospermum obliquum
Pterospermum obliquum
Oblique-leaved pterospermum
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Taxonomy
Family Malvaceae · Genus Pterospermum
Description
Pterospermum obliquum is a handsome tropical tree valued for its broad, glossy leaves and fragrant, pale flowers that often open at dusk. A graceful shade tree in warm, frost-free climates, it’s seldom seen outside botanical gardens or specialty collections but rewards growers with fast growth and winged seed pods that add interest after bloom.
Common Names
Oblique-leaved pterospermumWinged-seed tree
Context
nativeRegion
Tropical South to Southeast Asia (Indian subcontinent to Indochina).
usdaZones
10-12
companionPlants
Michelia champaca (Magnolia champaca), Syzygium cumini, Artocarpus heterophyllus, Alstonia scholaris
culturalUses
Planted as a shade/avenue tree; wood used locally for light construction, boxes, and pulp; flowers appreciated for fragrance.
Care
Care Requirements
LightFull sun to bright light; young plants appreciate light afternoon shade in very hot sites.
WateringKeep evenly moist while establishing; deep-water weekly in dry seasons. Once established, tolerates short dry spells. Avoid waterlogging.
SoilFertile, well-drained loam or sandy loam, pH 6.0–7.5; add organic matter and ensure good drainage.
FertilizerApply balanced, slow-release fertilizer in spring and mid-summer; supplement with compost mulch annually.
HumidityPrefers moderate to high humidity (50–80%); shelter from drying winds.
TemperatureThrives at 68–95°F (20–35°C); sensitive to frost. Protect below 50°F (10°C).
Growth & Life Cycle
HabitEvergreen to semi-deciduous tropical tree with a straight trunk and broad, rounded canopy.
Mature Size30–65 ft tall (9–20 m) and 20–40 ft wide (6–12 m), depending on climate and soil.
Growth RateModerate to fast in warm climates.
BloomingLate spring to autumn; creamy-white, often night-fragrant flowers followed by woody capsules with winged seeds.
DormancyNo true dormancy in tropics; may shed some leaves in cool or dry seasons.
Propagation
MethodsFresh seed, Semi-hardwood cuttings, Air layering
DifficultyModerate
Best SeasonSpring to early summer for cuttings/layering; sow fresh seed when pods ripen.
Maintenance & Notes
PruningLight structural pruning when young; remove dead or crossing wood after flowering. Avoid heavy cuts in peak heat.
RepottingBest planted in-ground; if container-grown when young, step up pot size as roots fill and avoid root-binding.
Pests & DiseasesScale, mealybugs, and aphids may occur; caterpillars occasionally. Watch for leaf spots and root rot in poorly drained soils.
ToxicityNot widely documented as toxic to humans or pets; avoid ingestion and contact with sap if skin is sensitive.
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