General Information

Habitat Requirements

Schiedea apokremnos grows in the crevices on nearly vertical coastal cliffs, from 60 to 330 m (200 to 1,100 ft) elevation. These cliffs have sparse, dry coastal shrub vegetation. Associated native species in the coastal dry cliff plant community includes Artemisia australis (ahinahina), Nototrichium sandwicensis (kului), Myoporum sandwicense (naio), Bidens forbesii (kookoolau), and Lipochaeta connata (nehe). In mixed dry to mesic cliffs associated native species include Artemisia australis, Bidens sandvicensis, Boehmeria grandis (akolea), Euphorbia celastroides var. hanapepensis (akoko), Lipochaeta connata var. acris, the Lobelia niihauensis, Nototrichium divaricatum (kului), N. sandwicense, Vaccinium dentatum (ohelo), Sida fallax (ilima), Wilkesia hobdyi (dwarf iliau), W. gymnoxiphium (iliau), Kadua cordata (kopa), Acacia koa (koa), Diospyros sandwicensis (lama), Dodonaea viscosa (aalii), Hibiscus kokio subsp. saintjohnianus (kokio ula), Metrosideros polymorpha var. glaberrima (ohia), Pipturus albidus (mamake), Pleomele aurea (hala pepe), Psydrax odorata (alahee), Polyscias racemosa, Rauvolfia sandwicensis (hao), Santalum freycinetianum var. pyrularium (iliahi), Leptecophylla tameiameiae (pukiawe), Xylosma hawaiiense (ae), Alyxia stellata (maile), Cocculus orbiculatus (huehue), Dianella sandwicensis (uki uki), Peucedanum sandwicense (makou), Pilea peploides, Smilax melastomifolia (pioi), Agrostis avenacea (heupueo), Carex meyenii, C. wahuensis, Cyperus phleoides, Eragrostis variabilis (kawelu), Heteropogon contortus (pili), Panicum lineale, Adiantum capillus-veneris (iwa iwa), Doodia kunthiana (okupukupu), Doryopteris decipiens (kumuniu), Microlepia strigosa (palapalai), Psilotum nudum (moa), Pteridium aquilinum var. decompositum (kilau), Selaginella arbuscula (lepelepe a moa), Sphenomeris chinensis (palapalaa), and Tectaria gaudichaudii (iwa iwa lau nui). Awaawapuhi has lowland diverse dry to mesic cliffs with Artemisia australis, Bidens sandvicensis subsp. sandvicensis, Euphorbia celastroides var. hanapepensis, Lipochaeta connata var. acris, and Nototrichium sandwicense. Trees and shrubs occasionally seen along the cliffs include Dodonaea viscosa, Metrosideros polymorpha var. glaberrima, Myoporum sandwicense, Psydrax odorata, Wilkesia gymnoxiphium, Doryopteris decipiens and Psilotum nudum.

Movement / Home Range

Schiedea apokremnos historically occurred only on Kauai from Nualolo Kai, Kaaweiki Ridge, and along a 10.5 km (6.5 mile) long section of the Na Pali Coast, including Milolii Valley, Kalalau Beach, Kaalahina and Manono Ridges, Haeleele Ridge, and as far north as Pohakuao Valley. It currently occurs along the Na Pali Coast at Haeleele, Nualolo Kai, and Awaawapuhi.

Reproductive Strategy

Schiedea apokremnos is a gynodioecious species, having hermaphrodite or female flowers (Sakai et al. 1997). Some individuals of S. apokremnos are functionally female and must be cross-pollinated to set seed. This reproductive strategy may be ineffective in populations with few individuals. In 2005, a new treatment of Schiedea was published, which discusses the genetic, cladistic, and phytogeographic relationships of Schiedea species at length, including S. apokremnos. Two findings mentioned there in relation to S. apokremnos are: 1) it has a condensed inflorescence which is typically found in species with dimorphic breeding systems, and appears to represent an adaptation for wind pollination; and 2) seed size in S. apokremnos does not correlate with habitat as it does in other Schiedea species, in that S. apokremnos has much smaller seeds than expected on the basis of habitat distribution. In most Schiedea species, selection favors large seed size in those species growing in either shaded, moist environments or in dry habitats. In these habitats, large seed size is adaptive because it permits establishment under conditions of rigorous competition or dry conditions (Wagner et al. 2005b). Schiedea apokremnos flowering cycles, pollination vectors, seed dispersal agents, longevity, specific environmental requirements, and limiting factors are mostly unknown.

Other

Schiedea apokremnos is distinguished from related species by shorter sepals, nectaries, and capsules. Schiedea apokremnos was first collected in the early 1900s by J.M. Lydgate from an unrecorded locality on Kauai. Harold St. John made the next collection at Nualolo Kai on the Na Pali Coast in 1965. Five years later, he described the taxon as a new species (St. John 1970b), naming it for the plant’s habitat of steep cliffs.