Arenga engleri, the Formosa palm, radiates a tropical beauty and is considered to be among the finest landscape and cultivated palms. This attractive clustering palm rarely grows more than 10 ft (3.1 m) tall with a stem diameter of 6 in (15.2 cm) and a spread up to 16 ft (4.9 m). The stems are cloaked with delicate black fibers. The Formosa palm has long graceful triangular fishtail-shaped (pinnate) leaves up to eight feet long. The dark olive-green leaves often twist gracefully, giving them a slight spiraling appearance. Leaflets spring from the midrib of each thornless stem, and are dark-green to olive on their topside, and silvery beneath. The 5-8 in (12.7-20.3 cm) long leaflets have an unusual and distinctive V (induplicate) cross-section and grow abundantly in a single plane off the stems. The spike like flower stalks are borne among the leaves and have both male and female flowers, so a single Formosa palm can produce fertile seeds by itself. The red, orange or green flowers have a sweet fragrance and produce red to deep purple fruits. Each globular fruit is less than 1 in (2.5 cm) in diameter and contains one to three seeds.
