Pahole Rare Plant Facility – FY 2010 Report

The plant inventory at Pahole Rare Plant Facility for fiscal year 2010 represented 39 threatened and endangered taxa with a total of 2674 plants. These plants are grown for restoration efforts and as a living genetic bank. This past year was a period of transition for this facility as the nursery site had undergone complete upgrades and renovations. The nursery stock was placed in a temporary facility while the nursery structures were cleared for a new facility. At the end of Fiscal year 2010, the framing of the greenhouse and flooring were completed.

In collaboration with Oahu Plant Extinction Prevention staff, Pahole Rare Plant Facility staff has focused efforts on 3 species. Silene perlmanii is extinct in the wild and known from a single population in the southern Waianae Mountain Range of Oahu. Plants grown at the Pahole Rare Plant Facility are clones of the last known wild individual. Seeds have been collected from these nursery plants over the last flowering seasons and deposited at the State Seed Storage Lab at Lyon Arboretum. Approximately 600 seeds were withdrawn in the later part of fiscal year 2010 and germinated. These are herbaceous plants that are relatively fast growing and are being transplanted from the seed trays. They are scheduled for initial out-planting in the later part of the 2011 out-plant season.

Cyrtandra kaulantha is limited to a small number of individuals found in a few small valleys of the windward Koolau Mountains of Oahu. This plant presents some very unique problems for propagation, restoration, seed collection, and storage. Previous experience has shown that seeds collected from wild plants were largely the product of hybridization. More common species of this genus are often found growing adjacent to this endangered species in wild habitat. This genus is known for its ease of cross pollination of its species. Because of this trait, clone propagation is a necessity. Because of growth habit of this species the typical stem cutting could potentially have a negative impact on the wild individual. Leaf cuttings from 10 wild individuals were collected very late in fiscal year 2010. Early indications are showing this to be a very hopeful method of clonal propagation for this species.

Gardenia brighamii was found in very limited numbers on Lanai, Molokai, Hawaii and Oahu. On Oahu there is one wild individual left in Nanakuli Valley of the Waianae Mountains. Pahole Rare Plant Facility has three individuals represented in the greenhouse, the extant plant and two extinct. Propagation efforts began in middle of fiscal year 2010. Stem cuttings are not in plentiful supply due to the slow growing nature of this plant. These cuttings are relatively slow to root, usually taking six to ten months to root. Staff has 38 plants from cuttings from two of the three founders. These will be ready for out-planting in 2011. Efforts are being made to refine cutting techniques to increase the percentage of rooting and hopefully speed rooting.

In a collaborative effort with Oahu Natural Area Reserve System staff, Pahole Rare Plant Facility staff has been propagating and growing plants of Colubrina oppositifolia, or kauila. 73 plants, representing 31 wild individuals originating from the northern Waianae Mountains, were out-planted on two separate outings. Volunteers from the Federal Department of Agriculture, staff from the Koolau Mountain Watershed Partnership, Oahu Plant Extinction Prevention Program, Oahu Natural Area Reserve System, and Pahole Rare Plant Facility participated in these out-plantings. These plants were planted within the fenced area of the Pahole Natural Area Reserve.

Another note regarding Colubrina oppositifolia – in a cooperative effort with Leeward Community College’s horticulturist, seven kauila plants, representing seven different wild individuals, have been plants on the campus. As expected from plants in an ex-situ horticultural environment, these plants have put on tremendous growth and development. Pahole staff will be monitoring for fruiting and collecting to check for seed viability and ultimately for seed storage,

In cooperation with the Oahu Army Natural Resources Program the grafting of Flueggea neowawraea has continued. Staff has successful grafts representing four wild individuals that have not been represented in the Oahu Army Natural Resources Program plant collection in the past. Individuals of this plant are still very difficult to propagate and much work is needed in getting better wild representation.

Staff has done very limited work with Cyrtandra polyantha, another Plant Extinction Prevention species, in the past and had gotten fair results with leaf cuttings. Pahole Rare Plant Facility staff will continue to pursue this technique of propagation with other species in this family and also look at its application to other taxa.

Pahole Rare Plant Facility provides yearly opportunities for the Oahu Rotary Club mentor program with local school groups; the High School Hiker section of the Oahu Sierra Club assisted with basic greenhouse construction during the complete renovation of the facility.

Inventory List for Pahole Rare Plant Facility for 2010

Species Number of individuals
Caesalpinia kavaiensis 18
Chamaesyce deppeana 9
Chamaesyce herbstii 5
Colubrina oppositifolia 88
Cyanea accuminata 1
Cyanea grimesiana ssp. grimesiana 6
Cyanea grimesiana ssp. obatae 148
Cyanea longiflora 59
Cyanea pinnatifida 11
Cyanea superba ssp. superba 73
Cyrtandra dentata 5
Dubautia herbstobatae 12
Eugenia koolauensis 31
Flueggea neowawraea 206
Gardenia brighamii 51
Gardenia mannii 2
Gouania vitifolia 11
Hedyotis parvula 12
Hesperomannia arbuscula 113
Isodendrion longifolium 8
Labordia cyrtandrae 42
Lepidium arbuscula 8
Lobelia monostachya 2
Lysimachia filifolia 8
Melicope lydgatei 2
Neraudia angulata 162
Nototrichium humile 282
Phyllostegia kaalaensis 36
Phyllostegia mollis 1
Phyllostegia parviflora ssp. lydgatei 16
Plantago princeps ssp. princeps 17
Pritchardia kaalae 195
Schiedea kaalae 307
Schiedea nuttallii 210
Schiedea obovata 258
Schiedea trinervis 5
Silene lanceolata 15
Silene perlmanii 26
Stenogyne kaalae ssp. sherffii 2
Viola chamissoniana ssp. chamissoniana 211