Herbarium Sheet Detail
NTBG Plant Name:
Lobelia niihauensis
Collector Name:
K. R. Wood
Collection Date:
August 13, 2004
Island Group:
HAWAIIAN ISLANDS
District:
Hanalei District
Locality:
Kalalau, up second stream crossing to back of southern valley.
Plant Description:
shrub, 50-100 cm tall, few branched, branches gray, with leaves clustered at tip, leaves green, costa purple-red, peduncle green, corolla purple, calyx green, comon on cliffs
Habitat:
Mixed mesic shrub cliff.
Associated Species:
W/ Chamaesyce celastroides var. hanapepensis, Artemisia australis, with Bidens sandwicensis, Nototrichium divaricatum, Sida fallax, Dodonaea viscosa, Wilkesia gymnoxiphium, and Wikstroemia oahuensis, shrubs of less common abundance include Dubautia microcephala, Lobelia niihauensis, Wilkesia hobdyi, Lepidium serra, and Hibiscus kokio subsp. saintjohnianus, occasional small terraces randomly perched along the vertical gradient where dominated by trees such as Acacia koa & A. koaia, Canthium odoratum, Diospyros spp., Metrosideros polymorpha, Pipturus albidus, Pipturus kauaiensis, and Psychotria mariniana, less common components of arborescent taxa include Melicope pallida, Nestegis sandwicensis, Pleomele aurea, Rauvolfia sandwicensis, and Santalum freycinetianum var. pyrularium, small herbaceous sub-shrubs also had an even and undisturbed distribution including Dianella sandwicensis, Lipochaeta connata var. acris, Lysimachia glutinosa, Peucedanum sandwicense, and Schiedea apokremnos, dominant grasses and sedges on these cliffs include Eragrostis variabilis, Panicum lineale, Carex meyenii, Carex wahuensis subsp. wahuensis, and Mariscus phleoides subsp. phleoides, occasional grasses and sedges include Luzula hawaiiensis var. hawaiiensis and Poa mannii, the more common ferns observed include Doodia kunthiana, Microlepia strigosa, and Selaginella arbuscula, the only observed vine was Alyxia oliviformis commonly seen within the shrub and arborescent zones, succulent herbaceous plants include Peperomia leptostachya and Peperomia tetraphylla.
Comments:
Kalalau Cliffs. Dry to mesic towering basalt cliff regions inaccessible to rats, goats, and pigs remain dominated by single island endemic species of plants which may have radiated from the older northwestern island chain and through isolation and time (5.1 million years) have further evolved on the northwest Na Pali coast of Kaua'i to create a unique ecosystem of cliff habitat species. Although the author has observed Kauai diverse dry to mesic cliffs from the northern Na Pali valley of Hanakoa to the southern end of Miloli`i, nowhere does it approach the diversity of life forms that is relictual in Kalalau. Primary factors responsible for the continuance of this unique biological community appear to be the survival of native birds and insects as seed dispersers and pollinators, but more importantly, to the sheer inaccessible nature of the ecosystem's vertically precipitous walls. Several sections of these fluted and weathered geological formations within Kalalau exceed 1000 feet of uninterrupted vertical gradient and represent an extraordinary biological community which will be referred to as the Kauai Diverse Cliff Community.
A future paper will describe all of the cliff regions inventoried within Kalalau, as this unique community stands apart from all the rest by its relatively undisturbed state. Much can be learned from studying the current biogeographical distribution and ecology of this region as it will enhance our understanding of insular evolutionary processes. High levels of endemism were most likely achieved by the slow transformation of a younger Kaua'i with her broad, undefined sloping sides giving way through time, erosion, and subsidence, to form the features of older islands (i.e., highly dissected sub-gulches, steep slopes, deep valleys, numerous micro-habitats and climates). In this successional process, populations of species which were previously continuous became isolated geographically and diverged morphologically to form what is left of Kalalau's flora today. Several nearby cliffs just beyond the survey area still contain several of the rarest plants known from the Hawaiian archipelago (i.e., Stenogyne campanulata, Remya montgomeryi, Hibiscadelphus woodii, Lysimachia scopulensis, Dubautia kenwoodii, Hedyotis st.-johnii, Plantago princeps var. anomala, Gouania meyenii, Schiedea attenuata & S. kauaiensis). It is the opinion of the author that a substantial portion of the biological manifestations which evolved in Kalalau before the arrival of mammals (i.e., man, cattle, goats, pigs, rats, dogs, cats) have been lost through habitat degradation and invasive species competition. Kalalau's highly dissected geological features still represent a refugium not only for the flora but for many forest and sea birds in addition to numerous other fauna.
The remote cliffs inventoried during this survey represent only a small part of Kalalau's total cliff community biota, yet these specific cliffs are habitat for many of the common to rare endemic cliff species. The method of this survey was to walk along the base of these cliffs and document with herbarium vouchers, and/or visual identification, all species seen in route.
Primary component's of the mixed mesic shrub cliff region include in order of abundance Chamaesyce celastroides var. hanapepensis, Artemisia australis, with Bidens sandwicensis, Nototrichium divaricatum, Sida fallax, Dodonaea viscosa, Wilkesia gymnoxiphium, and Wikstroemia oahuensis, shrubs of less common abundance include Dubautia microcephala, Lobelia niihauensis, Wilkesia hobdyi, Lepidium serra, and Hibiscus kokio subsp. saintjohnianus, occasional small terraces randomly perched along the vertical gradient where dominated by trees such as Acacia koa & A. koaia, Canthium odoratum, Diospyros spp., Metrosideros polymorpha, Pipturus albidus, Pipturus kauaiensis, and Psychotria mariniana, less common components of arborescent taxa include Melicope pallida, Nestegis sandwicensis, Pleomele aurea, Rauvolfia sandwicensis, and Santalum freycinetianum var. pyrularium, small herbaceous sub-shrubs also had an even and undisturbed distribution including Dianella sandwicensis, Lipochaeta connata var. acris, Lysimachia glutinosa, Peucedanum sandwicense, and Schiedea apokremnos, dominant grasses and sedges on these cliffs include Eragrostis variabilis, Panicum lineale, Carex meyenii, Carex wahuensis subsp. wahuensis, and Mariscus phleoides subsp. phleoides, occasional grasses and sedges include Luzula hawaiiensis var. hawaiiensis and Poa mannii, the more common ferns observed include Doodia kunthiana, Microlepia strigosa, and Selaginella arbuscula, the only observed vine was Alyxia oliviformis, this plant was commonly seen within the shrub and arborescent zones, succulent herbaceous plants include Peperomia leptostachya and Peperomia tetraphylla, invasive weeds in order of threat include Erigeron karvinskianus, Kalanchoë pinnata, Psidium guajava, Setaria gracilis, Pluchea carolinensis, Ageratum conyzoides, Vulpia bromoides, and Plantago lanceolata
Date of Record Creation:
August 1, 2012
Date of Last Update:
August 6, 2023
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