Corresponding author: Jason T. Cantley (
Academic editor: S. Knapp
Two species of
Cantley JT, Sporck-Koehler MJ, Chau MM (2016) New and resurrected Hawaiian species of pilo (
There are more than 110 species in the genus
Species belonging to the genus
Such is the case for currently described
The (re)discovery of bisulcate fruit with a depressed apex and a persistent crown-like calyx from a locally common
All measurements given herein are taken from dried herbarium specimens. Field observations were performed in September 2013, September 2014, and May 2015 to assess abundance and to take field notes and digital photos. Seeds of
Shrubs, multi-branched, erect, occasionally creeping and sometimes rooting at the nodes, or occasionally trees, often foetid when bruised. Leaves simple, opposite or rarely ternate, margins entire, petiolate or sessile; stipules interpetiolar, distinct or partly connate, entire or dentate with tooth-like marginal colleters. Flowers unisexual (and the plants dioecious or rarely monoecious), rarely polygamous or in one species perfect, axillary, solitary or in cymes; calyx 4–5(–10)-toothed, often reduced or absent in male flowers; corolla funnelform or campanulate, 4–5(–10)-lobed, lobes valvate in bud; stamens 4–5(–10), inserted at base of corolla tube; filaments long-exserted, erect or pendulous; ovary 2(–4)-celled, ovule 1 per cell, basal, anatropous; style 2(–4)-lobed, divided nearly to base; stigmas long-exserted, papillose-hirsute. Fruits drupaceous, fleshy, ovoid to globose, with 2(–4), 1-seeded, plano-convex pyrenes.
1 | Fruit reddish-orange, ovoid, lacking a central constriction between the two seeds, apex not depressed, calyx conspicuous or not | ( |
– | Fruit reddish-orange to yellow, cordate (heart-shaped) with a central constriction between the two seeds, apex depressed, calyx conspicuous and persistent, leeward East Maui |
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2 | Fruit reddish-orange to yellow, fruit calyx conspicuous and persistent and >1.5 mm long, East and West Maui |
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– | Fruit reddish-orange to yellow, persistent fruit calyx not present or sometimes minute (<1.5 mm), Kaua‘i, O‘ahu, Moloka‘i, Lana‘i, West Maui |
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Differs from other currently recognized species of
Field images of
Photo of the holotype specimen of
Flowering specimens were collected from August to September except for one individual in March. Field observations of September 2013 and 2014 found that most individuals of the population at Kanaio Natural Area Reserve and Auwahi were fruiting, and only few flowering. Fruiting specimens were collected across many months, but it is unknown how long fruits were mature on individuals prior to collection.
Known only from southern, leeward slopes of East Maui (Haleakalā) at elevations of approximately 1000-2000 m, roughly spanning east to west from the Kanaio Natural Area Reserve to the Kaupō Gap Trail. The linear distance is estimated at approximately 21 km, but populations may be disjunct, especially in poor, degraded habitat where ungulates and invasive plant species (i.e.
In native habitats,
The specific epithet refers to the heart-shaped fruit, which is a product of the central constriction of the fruit and depressed apex. This character is unique among Hawaiian
This taxon occurs as scattered individuals that are locally common within five populations on one volcano. When evaluated using the IUCN criteria for extinction risk ( Vulnerable
United States of America. Hawai‘i: Maui, East Maui, Haleakalā, alt. 3000-6000 ft, 1888,
Photo of the holotype specimen of
Most flowering specimens were collected from December to February and a lesser number from July to August. Specimens from Lihau (West Maui) are only known to flower in July. No individuals were fruiting or flowering in late September 2014 in Makawao Forest Reserve, but immature fruits and flowers were observed in May 2015. Most fruiting specimens occurred in July, but collections were made across many months.
Known from East and West Maui, but apparently more prevalent on East Maui. The taxon occurs from approximately 975m to 1700m elevation. On East Maui, it is known from mesic sites from Kīpahulu Valley to Olinda. Collections on West Maui are collected from Lihau and Honokawai.
Found in mesic to wet forests and shrublands with both native and non-native plant communities. Occurs primarily as an understory shrub to small tree. The rainfall varies dramatically across its distribution and precise collection localities should be geo-referenced to provide an accurate range of precipitation requirements for this taxon’s distribution.
The specific epithet refers to the persistent calyx on the fruit apex that looks like a crown (crown in Greek = stephanos) due to its persistence, connation, and irregular dentations.
When numerous collections of
Phenological observations suggest that
The taxonomic boundaries between
The recognition of
We would like to thank Ulupalakua Ranch, Keahi Bustamente, Diana Crow, Randy Kennedy, Peter Landon, Hank Oppenheimer, Bryon Stevens, and Casey Stewman for their help and organization to visit the Kanaio Natural Area Reserve and Auwahi populations of
Measurement
Measurements and notes taken from herbaria specimens.