Palapalai are among the most striking of the native Hawaiian ferns.  Their deep green color, intricately branched triangular fronds, and fine silvery hairs that sparkle in the sunlight make them a welcome sight in the native forests of Hawaii. 

Palapalai ferns (Microlepia strigosa) are indigenous to Hawaii and thrive under the shade of trees in cooler mountainous areas of all the major islands. 

This patch of palapalai ferns grows under kukui and guava trees on the slopes of the Waianae mountains along the Waianae Kai Trail that leads to the summit of Mount Kaala — the highest point on Oahu.  Palapalai ferns are important in Hawaiian culture.  Hula halua gather palapalai fronds from this site to make leis for their hula dances and as offerings to Laka, goddess of hula. 

Palapalai grow especially well in the wet montane forests of Kalopa on the Hamakua Coast of the Big Island.  These large palapalai fronds are triangular in shape and grow to up to 3 feet in length. 

The fronds of palapalai ferns have an intricate recursive branching and lobing pattern that gives them its nickname name — the lace fern. 

Here is an even closer shot of the branching pattern of palapalai ferns from the underside where the spores are beginning to form. This specimen grows in Kipuka Ki onthe slopes of Mauna Loa.

One of the more striking sights in the native forest is when sunlight filters through the forest canopy above and strikes a young palapalai frond. Young fronds are covered in fine silvery hairs that shimmer in the light. 

When new palapalai fern fronds grow their fronds start out a light green color and then become dark green as they grow into mature fronds. The tips of these young fronds have fine hairs that reflect the light with a silvery sheen.

Palapalai ferns propagate vegetatively by sending our runners and by sexually by spores.  This close-up photo of palapalai ferns show the spores in sori on the underside of this frond.  These spores are mature and will soon be released to start a new generation of ferns.

Sources:

Lyon Arboretum
How to Plant a Native Hawaiian Garden