You wouldn’t expect to find plants adapted to Alpine and dry upland conditions on a tropical island that has rain forests where annual precipitation often exceeds 380 cm (150 inches) a year. However, Maui has more than its share of these drylands survivors, some of them are more than a little unusual in appearance.
- Evening Primrose (Oenothera stricta)
The Evening Primrose (Oenothera stricta) is a native of Chile and Argentina, but it is naturalized in the Hawaiian Islands. This species is adaptable in the extreme: it grows in amongst medium-sized trees, tall shrubs, and grassland; it thrives in gravelly soil, sand, loam or clay. It is known to occupy roadsides, wasteland, and disturbed natural vegetation. This individual was found growing in an open field near the Hosmer Grove entrance to Maui’s Haleakala National Park.
- Air Plant (Kalanchoe pinnata)
The Air Plant (Kalanchoe pinnata) is native to Madagascar but is naturalized in Hawaii. It has a high tolerance for heat but not extended periods of time in direct sunlight. It favors protected, partially-shaded spots in rocky or sandy soil. Like the Chandelier Plant (to which it is related), it propagates quickly from plantlets that form along its leaf margins and drop to the ground, forming dense colonies of numerous offspring.
- Hairy Abutilon (Abutilon grandifolium)
The Hairy Abutilon (Abutilon grandifolium) is a naturalized tropical weed. Its favorite habitat is waste areas, open fields, and along roadsides, especially in arid regions. The seed pods (just above and to the immediate right of the flower) turn black when mature, as in this photo.
- Silversword (Argyroxiphium sandwicense)
I found this immature Silversword (Argyroxiphium sandwicense) growing on open ground near the summit of Haleakala volcano. This species evolved from a Tarweed and is able to tolerate the Alpine Desert conditions found at the summits of the volcanic peaks above 10,000 feet on Maui and the Big Island. It has very shallow roots, ideal for gleaning what little moisture is present in the poor soils. It only sets its immense flower spike once every 20 years. Although still classified as an endangered species, it is recovering nicely within Haleakala National Park now that feral goats have been controlled within the park boundary.
- Prickly Pear Cactus (Opuntia ficus-indica)
This Prickly Pear Cactus (Opuntia ficus-indica) in growing in a cattle pasture fronting on Pulehu Road, north Maui. It is a naturalized alien species introduced from Mexico in 1809. It became such a serious pest in open pasture lands throughout the Islands that insects were introduced (1949 to 1960) as a biological control. Though not referred to as a “tree”, many of the plants in this and other pastures in the area exceed 4 meters in height.
- Spur Flowers (Plectranthus parviflorus)
Spur Flowers (Plectranthus parviflorus) making a go of it in the cracks an crannies of a scoriacious basalt outcrop, and old lava flow near Kanaio. These indigenous Hawaiian shrubs are related to the mint family, but the fleshy leaves have no scent when crushed. The much taller branches die away after flowering, as they have in this photo. The delicately veined leaves are covered with numerous fine hairs. The largest of these individuals was about 4 cm across.
- Mother of Millions (Kalanchoe delagoensis)
The Chandelier Plant (Kalanchoe delagoensis) is also known as the Mother-of-Millions in Australia, where it is rightly classified as a weed because of its tendency to propagate itself very quickly. Like the Air Plant, it is a native of Madagascar but it has become naturalized in the Hawaiian Islands. Easily mistaken for a cactus (Euphorbia), it is not as hardy, though it is very heat and drought resistant. This individual and its numerous offspring are growing on a barren lava flow near Ulupalakua.
Tags: Abutilon grandifolium, Air Plant, Alpine desert plants, Argyroxiphium sandwicense, Chandelier Plant, drylands, Evening Primrose, Hairy Abutilon, Kalanchoe pinnata, Kalanchoe tubiflora, Maui's drylands plants, Maui's Ecosystems, Mother-of-Millions, non-native Hawaiian plants, Oenothera stricta, Plectranthus parviflorus, Silversword, Spur Flower
