THE FERNS. The Sliding Sands Trail drops from White Hill on bare slopes of red and gray Cinders. As it levels below Puu o Pele, a lush, green carpet spreads along the south wall of the crater. It is a surprise to discover that ferns compose the verdure, for several kinds find the shelter of the cliffs agreeable. Haleakala’s KA’UPU, Polystichum haleakalense Brack., a rather coarse, low plant with scaly stems, grows among the shrubs. The pellucid polypody, ’AE, Polypodium pellucidum Kaulf., and the maidenhair spleenwort, ’IWA’IWA, Asplenium adiantum-nigrum L., grow here, but they are common elsewhere as well. Iwaiwa is a small plant with shiny, slender stems and stiff, triangular fronds that thrives in the brush. On Leleiwi Pali it is a tiny thing, clinging to the rocks. This fern is known in mountainous regions in many countries. Another maidenhair spleenwort, ’OWALI’I, Asplenium trichomanes L., makes its home on barren lava above 5,000 feet on the inner slopes of the crater. Its small, opposite, rounded or ovate frond segments, pinnae, grow on wiry stems that form dense clumps. Look for it along Halemauu Trail on Leleiwi Pali. It is found in the temperate zones and on high mountains in many parts of the world.

Bracken, KILAU, Pteridium aquilinum var. decompositum (Gaud.) Tryon, a stiff cosmopolitan, is among the best-known ferns. It grows in grassy spots inside and outside the crater. Foraging pigs, seeking its tasty rootstocks, often uproot it in the forests. The young leaves of AMA’UMA’U, Sadleria cyatheoides Kaulf., add a touch of red along Halemauu Trail on Leleiwi Pali. At Paliku, several moisture-loving ferns grow on logs, rocks, and moss-covered trees. Large, dense ae are quite unlike the frail specimens on Leleiwi Pali. The following can be seen in damp spots and on tree trunks: Maui’s paddle, ’EKAHA, Elaphoglossum reticulatum (Kaulf.) Gaud., with paddle-shaped blades 6-12 inches long; ’EKAHA-’AKOLEA, Pleopeltis thunbergiana Kaulf., a small fern with tough, pale, elliptico-oblong (paddle-shaped) fronds; and MOA, Psilotum complanatum Sw., belonging to a small group of tropical plants, PSILOTALES, which reproduce by spores, but are distinct from true ferns, clubmosses, and the better-known orders.

Swordfern, NI’ANI’AU or ’OKUPUKUPU, Nephrolepis exaltata (L.) Schott., is widely distributed at Haleakala as it is elsewhere in Hawaii. Cliffbrake, KALAMOHO LAULI’I, Pellaea ternifolia (Cav.) Link, grows among rocks in dry, sunny locations at higher elevations above the park entrance and inside the crater. It is common. The bluish-green pinnae of this short, slender fern grow on opposite sides of the dark, wiry stems. They are cleft into three linear segments.

THE NATIVE GRASSES. Several native grasses grow above the park entrance: Trisetum glomeratum (Kunth) Trin., Deschampsia australis forma haleakalensis Skottsb., and Agrostis sandwicensis Hillebr. The Trisetum, also common inside the crater, is called mountain pili, PILI being the lowland grass known in many tropical regions and used for thatching houses in Hawaii. The Hawaiian name for T. glomeratum is PILIUKA, upland pili. In some places it is also called HE’U PUEO, the hoot of an owl.

All three grasses are tufted, i.e., bunch grasses. The Deschampsia has tough, wiry blades (leaves) with shiny, open panicles of flowers and seeds. The Agrostis has stiffly upright blades and culms (jointed stems) with spike-like panicles. The pili has flat blades usually covered with soft hairs. The panicles are contracted or spike-like.

THE SEDGES. Fig. 1. Sedges are generally grasslike wind-pollinated herbs that grow in tufts or bunches. They are often the dominant plants in cold marshes, especially in the Arctic. They have little economic value and grazing animals find them unpalatable. Some have tough, pliable stems that are woven into mats and baskets; some have fruiting spikes that are attractive in dry bouquets. Most have 3-angled stems around which the blades are ranked. The inconspicuous, green flowers are crowded in tight, flattened spikes, often grouped on top of a slender, grasslike stem. Hawaii has a dozen or more native genera with many of its species widespread in the world.

The species common on the upper slopes of Haleakala and on the crater floor, Gahnia gaudichaudii Steud., bears shiny, ebony fruits. These can dangle, suspended by the wilted, threadlike stamens for more than a year from the fruiting stalk. Another sedge, Carex macloviana subfusca (W. Boott) Kukenth., grows in clumps along the south wall. The fruiting stalks bear cylindrical or ovoid clusters of 4-9 spikelets, each ½-1 inch long. This sedge grows from Lapland and Greenland to northern South America, but in Hawaii it has been found only on Haleakala and Kohala Mountains above 4,000 feet. The Hawaiian variety was first described from a specimen collected at Lake Tahoe, California. The interesting Oreobolus furcatus H. Mann, mentioned as occurring on West Maui, also grows in Koolau Gap.

RUSH, Luzula hawaiiensis (O. Ktze.) Buch. A visitor brought me a small tufted plant with grass-like leaves covered with soft, silky hairs. He was all excited, believing he had found a young silversword on the cinder flats near the summit of Mt. Hualalai. The plant was the endemic rush that lives in wet places above 3,000 feet in the mountains of Maui, Hawaii, and Kauai. In Haleakala Crater, I found it on Leleiwi Pali and near Paliku, where others might mistake it for an immature silversword or greensword. The Hawaiian general name for grasses, sedges, and rushes is MAU’U.

PAINIU, Astelia degeneri Skottsb. This plant is reported by Degener to be growing within the crater.[19]

MAU’U-LA’ILI, Sisyrinchium acre H. Mann. A native member of the Iris Family with grass-like leaves that grows on old lava flows between altitudes of 3,500 and 7,500 feet on Maui and Hawaii. It is an attractive plant that rarely exceeds 12 inches high. In July and August it bears yellow flowers ¾ inch across that last only a few hours. In the crater it may be found in Koolau and Kaupo Gaps. The leaves, bound tightly around the wrists and ankles, stain the skin a blue color that lasts several days. This stain was regarded as proof that a person had been to the crater. A number of other species of the genus are mainland wildflowers commonly called blue-eyed grass.

ORCHIDS. Fig. 2. The Orchid Family of over 15,000 species is second only to the Composite Family in size, yet only three species of three genera are native in Hawaii, a land connected in thought with an exuberance of gay orchids. Moreover, the three endemic species are characterized by small size, relative rarity, and inconspicuous flowers. Twayblade, Liparis hawaiiensis H. Mann, grows in open woods on the ground and on moss-covered trees on the flanks of the volcano and at Paliku. The rarest of the three natives, Habenaria holochila Hillebr., has been found growing 1-2½ feet high in deep moss in fog-swept Koolau Gap. It bears its dull-greenish, inconspicuous orchids on a tall, many-flowered spike.

’ALA ’ALAWAINUI, Peperomia sp. A small herb with succulent leaves found at Paliku. It is a member of the Pepper Family, Piperaceae, to which AWA, Piper methysticum, belongs. There are many Peperomias native to Hawaiian forests. Some have leaves with gay red undersides.

SANDALWOOD, ’ILIAHI, Santalum haleakalae Hillebr. Fig. 3. A small but striking tree found above the park entrance, in Koolau Gap, and along the Kaupo Trail below Paliku. It has leathery, dark green leaves so that it stands out in the vegetation and is readily distinguished from afar. In mid-summer, corymbs of four-pointed, deep-red or vermillion flowers appear on the ends of branches. The dry heartwood has the fragrance which is associated with the name sandalwood. Degener tells the detailed story of sandalwood trade that flourished in the islands for fifty years beginning in 1790.[20]

SHEEP SORREL, Rumex acetosella L., an abundant, well-known, introduced weed found both inside the crater and out. A native species called PAWALE, Rumex gigantius Ait., is more interesting. It grows as a stocky undershrub on barren lava flows and in rock crevices inside the crater. In Koolau Gap, it becomes a sprawling vine. It is said that a mixture of an extraction from the boiled bark and AWA was used by Hawaiians for skin diseases. This was tried in vain as a cure for leprosy when the disease first appeared in the islands in 1840.

HAWAIIAN BUTTERCUP, MAKOU, Ranunculus hawaiiensis A. Gray. Like the native violets and geraniums, members of this genus, well-known on the mainland, either become bushy or spread as a woody vine in Hawaii. Two native species occur on Haleakala, but the yellow-flowered, sprawling R. mauiensis A. Gray is reported only outside the park. The larger flowered, erect Hawaiian buttercup, however, was reported by J. F. Rock to be abundant formerly in Puu Nianiau Crater. It is a coarse, hollow-stemmed, hairy herb with compound leaves divided into three sharply-toothed, irregular leaflets. Within Haleakala Crater it grows on moist, grassy slopes in Koolau Gap.

HO’AWA, Pittosporum confertiflorum A. Gray. A small tree, sometimes becoming 25 feet tall. The large leaves, shiny green on top, brown hairy underneath, are crowded like whorls on the ends of the branches. In the centers of these, dense clusters of fleshy, cream-colored flowers appear in late summer. Wrinkled fruits, resembling English walnuts, hang on the trees throughout the year. Very few trees grow in the crater, but they are more numerous above 4,000 feet along the Kaupo Trail and at Ulupalakua. The genus of some 200 species is widespread; it has many species native to Hawaii. Some kinds are well-known garden plants. Pittosporum tobira (Thunb.) Ait., a native of China and Japan, is a favorite shrub in California.

HAWAIIAN HAWTHORN, ’ULEI, Osteomeles anthyllidifolia Smith (Lindl). A spreading shrub with compound leaves and fragrant, small, white flowers, like apple blossoms, that may appear throughout the year. The fruit is white and contains five stony seeds. Plants growing on ash flats are very small. The strong but pliable wood of ulei was used for digging sticks, fish spears, and hoops to keep the mouths of fishing nets open.

HAWAIIAN RASPBERRY, ’AKALA, Rubus hawaiiensis A. Gray. Fig. 5. A shrub with attractive pink flowers abundant at Paliku. It is found also in Koolau Gap at the foot of Leleiwi Pali and elsewhere. The fruit, agreeable but somewhat bitter, is remarkable for its large size. It ripens about the Fourth of July or later. A trailing native, R. macraei A. Gray, sprawls in foggy Koolau Gap. Its large, dark fruits are bitter.

MAMANE, Sophora chrysophylla Salisb. Fig. 4. A common native shrub or small tree of the Bean Family both inside and outside the crater up to tree line. It is recognized by more or less downy, narrow, compound leaves, racemes of yellow flowers, and twisted pods that have four wings and are constricted between the seeds. Goats eat it greedily and quickly exterminate it in an area. The hard, durable wood was used by Hawaiians in many ways; today it is a principal firewood for the crater cabins. A tree in full bloom is a beautiful object. The height of the flowering season is mid-spring.

GERANIUM, NOHOANU, HINAHINA. Fig. 6, 7. Neurophyllodes tridens (Hillebr.) Degener & Greenwell is common above the park entrance and on the south wall within the crater. It sometimes becomes three feet tall and is readily identified by its silvery leaves, each of which has three small teeth on the end. The white flowers have purplish veins especially toward their centers. The blooming season is July to October. The silvery aspect of the plant, like the silversword, is imparted by a mesh of fine white hair that reflects the light of a passing car as effectively as the glass-beaded paint of directional signs.

Two native geranium relatives grow in Koolau Gap, N. ovatifolium (A. Gray) Degener & Greenwell and its variety superbum. The latter is common on the trail to Waikau not far from the foot of Leleiwi Pali.

One of the common plants growing on the crater floor is the exotic pink-flowered G. carolinianum var. australi (Benth.) Fosberg whose pointed fruiting bodies give it the common name, cranesbill.

HAWAIIAN HOLLY, KAWA’U, Ilex anomala Hook and Arn. The forest growing on the talus behind the Paliku cabins is the finest within the crater. A striking tree of this association is the Hawaiian holly that has dark, shiny, oval leaves with conspicuous networks of slightly depressed veins that make identification easy. Dense panicles of small, white flowers are followed by shiny, black drupes, like Christmas holly “berries.” The genus is that of the English holly. Curiously, the scientific name has been locally corrupted to ileck.

OLOMEA, Perrottetia sandwicensis A. Gray. A native shrub or small tree belonging to the same family as the bittersweet of the continent. The numerous tiny, round, red fruits, borne in panicles, suggest the relationship. The bright red venation of leaves and petioles make the plant easily recognized. I know of no plants within the park, but found many trees a thousand feet below the park boundary in Keanae Valley.

A’AL’II, Dodonaea eriocarpa Smith. Fig. 8. This is a common shrub in several varieties along the highway and in the western end of the crater. At Paliku and Kaupo Gap it becomes a tree up to 20 feet high and 8 inches in diameter. Its flowers are inconspicuous but clusters of dry, reddish fruit-capsules contrast, flower-like, with the surrounding green foliage. The fruits, abundant from July to September, are used for leis and dry bouquets. The hard brown heartwood was used for spears, pololu, daggers, pahoa, and other implements.

BEGONIA—PUAMAKANUI, Hillebrandia sandwicensis Oliv. (See illustration p. 53.) The only native begonia, found in wet ravines often by waterfalls. It grows profusely at Koolau a mile below Holua Cabin at the foot of the rain-drenched pali. This succulent herb has a tuberous rhizome, unbranched, slender stems, and hairy, toothed leaves 4-10 inches in diameter. From June to August it bears sprays of bright, pink and white flowers. This is one of the floral treasures of Hawaii.

TARWEED. Cuphea carthagenensis (Jacq.) McBride. A low, sticky, hairy perennial from tropical America widely spread at lower elevations in the park. It has red or green branches, small ovate leaves, and tiny but not unattractive pink flowers ¼ inch across. Plants in rock crevices on cliffs are tiny; on the crater floor, they may become a foot high and form a dense shrubby mat over a sizeable area. The plant belongs to the LYTHRACEAE or Crepe Myrtle Family.