Scientific name: Ptychosperma macarthurii

POWO Status: Tree

IUCN Red List threat level: Least Concern

GPS Location: 17° 42′ 55.01″ N, 64° 49′ 44.24″ W

Observations:

Phenological Markers – Ptychosperma macarthurii

Common Name: Macarthur Palm, Macarthur’s Palm
Scientific Name: Ptychosperma macarthurii (F. Muell.) H.Wendl.
Family: Arecaceae (Palm family)

Leaf Phenology

Leaf Type: Pinnate leaves with long, narrow leaflets
Evergreen/Semi-deciduous: Evergreen
Leaf Flush: New leaves typically emerge during the warmer, wetter months, with some growth year-round in tropical climates
Senescence: Minimal leaf drop in stable environments, with occasional yellowing during drought or stress conditions
Phenological Indicator: Appearance of new leaves, characterized by long, slender leaflets, especially during the wet season or after significant rainfall

Flowering

Inflorescence: Creamy-white to yellowish flowers in pendulous racemes
Blooming Period (Tropics): Primarily in late spring to summer
Pollinators: Attracts bees, butterflies, and other insects
Phenological Indicator: Long, drooping flower clusters visible from the top of the crown; flowers gradually opening from base to top of the raceme

Fruiting

Fruit Type: Small, round, red or purple fruits
Fruit Development: Fruits develop shortly after flowering, typically ripening in late summer to fall
Dispersal: Fruits are primarily dispersed by birds, although gravity also plays a role
Phenological Indicator: Clustered red or purple fruits, visible in the late summer or early fall as the flowers fade

Suggested Photo Angles

• Full palm in context to show the slender, upright trunk and the canopy of long, pinnate leaves
• Close-up of individual leaflets to showcase their fine, segmented structure
• Flowering spikes with emerging buds or open flowers, particularly in the raceme’s lower section
• Developing and mature fruits, especially as the color changes from green to red or purple
• Leaf flush or seasonal leaf drop (if observed) during periods of growth or stress

Notes for Monitoring

Although slow-growing, it can live for decades and is typically part of shaded understory plantings in natural habitats

Flowering may be influenced by the seasonal monsoon patterns in tropical areas

The palm is commonly found in tropical and subtropical environments, often along rivers, in rainforests, or in well-watered garden settings