Pahole Rare Plant Facility – FY 2009 Report

Objectives

The conservation of rare plants on the island of Oahu by using genetic management, plant propagation, restoration, and reintroduction for the sole purpose to increase plant numbers, stabilize existing populations, and initiate new populations of endangered plants.

Approach

  1. Collaboration on plant collections, management, inventory, and restoration/reintroduction efforts with government agencies, private landowners, and botanical gardens.
  2. Focus on the propagation, primarily on the Oahu endangered plants whose natural habitats exist on State lands, wildlife sanctuaries, natural area reserves, and forest reserves. This includes establishment of ex situ plantings in the nursery, increase numbers of plants/species, germplasm storage within the nursery or surrounding Pahole area (e.g., stock plants).
  3. Establish broad ex situ genetic representation of the targeted plant species by maintaining an inventory database, and working in collaboration with the various agencies and land managers.
  4. Assist in the reintroduction/restoration efforts that directly involve the plants produced at the Pahole Rare Plant Facility.

Performance

The plant inventory at Pahole Rare Plant Facility for fiscal year 2009 represented 55 threatened and endangered taxa with a total of 3,722 individual plants. These plants were grown for restoration efforts and as living collections.

Inventory List: Abutilon menziesii 26, Caesalpinia kavaiensis 22, Chamaesyce deppeana 17, Colubrina oppositifolia 174, Cyanea acuminata 1, Cyanea crispa 1, Cyanea grimesiana subsp. obatae 229, Cyanea longiflora 38, Cyanea pinnatifida 11, Cyanea superba subsp. superba 238, Cyanea truncata 2, Cyperus trachysanthos 6, Cyrtandra dentata 5, Cyrtandra polyantha 23, Cyrtandra tintinnabula 2, Delissea subcordata 1, Dubautia herbstobatae 50, Eugenia koolauensis 25, Flueggea neowawraea 150, Gardenia brighamii 25, Gardenia mannii 1, Gouania vitifolia 89, Hedyotis degeneri subsp. degeneri 1, Hedyotis parvula 4, Hesperomannia arbuscula 175, Hibiscus brackenridgei 6, Isodendrion longifolium 5, Kokio drynariodes 4, Labordia cyrtandrae 41, Lepidium arbuscula 8, Lobelia monostachya 2, Lysmachia filifolia 7, Melanthera tenuifolia 144, Melicope adscendens 1, Melicope lydgatei 2, Neraudia angulata 248, Nototrichium humile 130, Peucedanum sandwicense 1, Phyllostegia kaalaensis 206, Phyllostegia mollis 1, Phyllostegia parviflora subsp. lydgatei 15, Phyllostegia racemosa 1, Plantago princeps subsp. princeps 25, Pritchardia kaalae 218, Scaevola coriacea 1, Schiedea adamantis 46, Schiedea kaalae 254, Schiedea nuttalii 347, Schiedea obovata 432, Schiedea trinervis 40, Silene lanceolata 17, Silene perlmanii 20, Urera kaalae 5, Viola chamissoniana subsp. chamissoniana 173.

Propagation

A new strategy for plant notoriously difficult to propagate was started late in fiscal year 2009. Flueggea neowawraea is notoriously difficult to propagate by asexual means. A number of wild representatives have been in propagation for many years with repeated failed attempts utilizing cuttings and air layers. The horticulture staff at the Pahole Rare Plant Facility has started grafting wild collected scion wood onto nursery produced seedling rootstock. By the end of fiscal year 2009 there has been success in grafting two individuals of Flueggea neowawraea from the Pahole Natural Area Reserve; there are only four individuals of this species remaining in this area. Collections of scion wood from an additional five individuals from the Makaleha Forest Reserve have been made and grafts will be made at the very end of fiscal year 2009. Grafting is looking very promising for the propagation of this species.

Eugenia koolauensis is a species that has been very difficult to propagate asexually. Several attempts of collecting cutting material from wild populations were done in fiscal year 2009. These collections have yielded 21 rooted cuttings representing six wild individuals. No propagation protocols have been developed yet for this species. There is much work to be done to efficiently propagate this species in cooperation with Oahu Army Natural Resources Program.

Reintroduction

During the outplant season for 2009, 19 plants of Colubrina oppositifolia and one plant of Caesalpinia kavaiensis was planted. This effort was brought about with the cooperation of the Oahu branches of Wildlife and Forestry Divisions, the Natural Area Reserve System, and the Pahole Rare Plant Facility. Maintenance and watering of this outplanting has been done by the Pahole Rare Plant Facility horticulture staff.

Six plants of Colubrina oppositifolia have been planted at the University of Hawaii. These plants were from rooted cuttings from six different wild individuals. These were planted as an ex situ site for the purpose of seed production and collection. By the end of fiscal year 2009, all of the plants had flowered and one individual had set fruit.