Delissea rhytidosperma H. Mann (Campanulaceae) and Phyllostegia kahiliensis H. St. John (Lamiaceae) possibly extinct on Kaua`i, Hawaiian Islands. Bishop Museum Occasional Papers 116: 31–33

Abstract

Of the estimated 1191 native flowering plant and fern species in Hawai'i, ca. 10% have not been documented for many years and are presumed to be extinct. two possible new plant extinctions on Kaua'i are reported here, Delissea rhytidosperma H. Mann (Campan ul aceae) and Phyllostegia kahiliensis H. St. John (Lamiaceae), bringing the total number of known or possible/probable plant extinctions in Hawai'i to 112 taxa (Wood 2007, 2012, 2014). the pronouncement of extinction is potentially fallible and is here inferred from the absence of observation/collection records and the passing of all known wild individuals (Wood 2012). A current analysis of Hawai'i's plant extinctions by the author indicate that 44% involved birds for pollination services and 96% depended on birds for seed dispersal. It is relevant to note that the Hawaiian Islands have lost 79 native bird species to extinction and are left with only 32 (James & olson 1991; olson & James 1991; Burney et al. 2001; Boyer 2008). With two-thirds of the surviving forest bird species in Hawai'i being critically endangered and a continued decline in native arthropods, there is grave concern for the endangered Hawaiian flora and for their unique insular relationships with biodiversity as a whole. even today, little is known about the life cycles, breeding system variations, and habitat preferences found in the Hawaiian flora. the great majority of Hawaiian plant extinctions (i.e., 35 taxa) have occurred in the Hawaiian lobeliads (Cam panulaceae), a family renowned for their co-evolution with Hawai'i's honeycreeper birds, in the endemic subfamily drepanidinae of the Fringillidae or finch family (Wood 2014). the Lamiaceae or mint family falls second in Hawaiian plant extinctions with 16 members having no known wild individuals remaining. Besides the decline of native pollinators and seed dispersers (Kearns et al. 1998; Milberg & tyrberg 1993; Wood 2012), an increase in endemic plant extinctions throughout the islands of oceania is commonly associated with habitat deterioration from invasive non-native plants and animals, anthropogenic factors that further the loss and fragmentation of natural habitats, devastation by severe storms, and a weak regional conservation ethic with inadequate funding. other prominent factors indicating plants are at risk of extinction are their low historic population densities, very narrow geographic range, and strict habitat requirements (Sakai et al. 2002; Wood 2007), all of which correlate closely to the possible extinction of Delissea rhytidosperma and Phyllostegia kahiliensis. Campanulaceae Delissea rhytidosperma H. Mann Possibly extinct the endemic Hawaiian genus Delissea Gaudich. was historically known from 15 species distributed across all the main Hawaiian Islands except Kaho'olawe, with each endemic to a single island (Lammers 2005). two taxa, D. kauaiensis (Lammers) Lammers and D.

Full text

Delissea rhytidosperma H.Mann (Campanulaceae) and
Phyllostegia kahiliensis H.St.John (Lamiaceae)
possibly extinct on Kaua‘i,Hawaiian Islands1
KENNETH R. WOOD
National Tropical Botanical Garden, 3530 Papalina Road, Kalāheo,
Kaua‘i, Hawai‘i 96741, USA; email: kwood@ntbg.org
Of the estimated 1191 native flowering plant and fern species in Hawai‘i, ca. 10% have not
been documented for many years and are presumed to be extinct. Two possible new plant
extinctions on Kaua‘i are reported here, Delissea rhytidosperma H. Mann (Campan ul aceae)
and Phyllostegia kahiliensis H. St. John (Lamiaceae), bringing the total number of known
or possible/probable plant extinctions in Hawai‘i to 112 taxa (Wood 2007, 2012, 2014). The
pronouncement of extinction is potentially fallible and is here inferred from the absence of
observation/collection records and the passing of all known wild individuals (Wood 2012).
A current analysis of Hawai‘i’s plant extinctions by the author indicate that 44% involved
birds for pollination services and 96% depended on birds for seed dispersal. It is relevant to
note that the Hawaiian Islands have lost 79 native bird species to extinction and are left with
only 32 (James & Olson 1991; Olson & James 1991; Burney et al. 2001; Boyer 2008). With
two-thirds of the surviving forest bird species in Hawai‘i being critically endangered and a
continued decline in native arthropods, there is grave concern for the endangered Hawaiian
flora and for their unique insular relationships with biodiversity as a whole. Even today, lit-
tle is known about the life cycles, breeding system variations, and habitat preferences found
in the Hawaiian flora. The great majority of Hawaiian plant extinctions (i.e., 35 taxa) have
occurred in the Hawaiian lobeliads (Cam panulaceae), a family renowned for their co-evo-
lution with Hawai‘i’s honeycreeper birds, in the endemic subfamily Drepanidinae of the
Fringillidae or finch family (Wood 2014). The Lamiaceae or mint family falls second in
Hawaiian plant extinctions with 16 members having no known wild individuals remaining.
Besides the decline of native pollinators and seed dispersers (Kearns et al. 1998; Milberg &
Tyrberg 1993; Wood 2012), an increase in endemic plant extinctions throughout the islands
of Oceania is commonly associated with habitat deterioration from invasive non-native
plants and animals, anthropogenic factors that further the loss and fragmentation of natural
habitats, devastation by severe storms, and a weak regional conservation ethic with inade-
quate funding. Other prominent factors indicating plants are at risk of extinction are their
low historic population densities, very narrow geographic range, and strict habitat require-
ments (Sakai et al. 2002; Wood 2007), all of which correlate closely to the possible extinc-
tion of Delissea rhytidosperma and Phyllostegia kahiliensis.
Campanulaceae
Delissea rhytidosperma H. Mann Possibly extinct
The endemic Hawaiian genus Delissea Gaudich. was historically known from 15 species
distributed across all the main Hawaiian Islands except Kaho‘olawe, with each endemic
to a single island (Lammers 2005). Two taxa, D. kauaiensis (Lammers) Lammers and D.
31
Records of the Hawaii Biological Survey for 2014. Part I:
Articles. Edited by Neal L. Evenhuis & Scott E. Miller. Bishop
Museum Occasional Papers 116: 31–33 (2015)
1. Contribution No. 2015-005 the Hawaii Biological Survey.
Published online: 5 May 2015 ISSN (online): 2376-3191

rhytidosperma, are recognized from Kaua‘i. Delissea kauaiensis is currently known from
only six mature and two immature individuals and D. rhytidosperma is reported here as
recently extinct in the wild, bringing the total number of extinct Delissea species to
twelve, with the remaining three on the edge of extinction.
Specimens of Delissea rhytidosperma were historically collected in several Kaua‘i
mesic forest locations, namely Hanakāpī‘ai, Hanapēpē, Hā‘upu, Kēalia, Kīpū, Limahuli,
Wahiawa, and Wainiha (HBMP 2011; Lammers 2005). In recent decades botanists have
monitored relictual colonies in the Hanakāpī‘ai, Hā‘upu, and Limahuli Valleys and the
National Tropical Botanical Garden (NTBG) has successfully brought this species into
cultivation. It is recommended that further careful efforts be made to rediscover D. rhyti-
dosperma near previously known colonies around Hanakāpī‘ai and Hā‘upu and new
efforts be initiated to explore some of the mesic cliffs and steep slopes of Kēalia and
Moloa‘a Forest Reserve.
Material examined. KAUA‘I: Mt. Hā‘upu (Hoary Head Range), below Queen Victoria profile,
rock outcrop, north exposure, 980 ft elev., multi-branched shrub of 4 ft, 12 Jan 1984, Flynn 737
(PTBG); loc. cit., 12 Jan 1984, Flynn 738 (PTBG); loc. cit., 12 Jan 1984, Flynn 739 (PTBG); loc. cit.,
12 plants, 2–10 ft height, with flower and fruit, 27 Feb 1992, Perlman, Wood & Flynn 12611 (PTBG);
loc. cit., 4 plants, 9 seedlings, 2–3 ft height, with fruit, 900 ft elev., 20 Oct 1994, Perlman & Wood 14478
(PTBG); loc. cit., 12 plants, 1.5–2.5 m tall, plants scattered on cliff, 23 May 2001, Perlman 17562
(PTBG); loc. cit., 988 ft elev., 22 Jul 2004, Tangalin 147 (PTBG); loc. cit., 320 m elev., 19 Aug 2005,
Tangalin 426 (PTBG); Hanakāpī‘ai Valley, east side of stream, 5 plants, 820 ft elev., 29 Dec 1999,
Perlman et al. 16918 (PTBG).
Lamiaceae
Phyllostegia kahiliensis H. St. John Possibly extinct
Phyllostegia Benth. is composed of 34 species, 32 of which occur in the Hawaiian Islands.
Intriguingly there are two disjunct extra-Hawaiian species that include a single species
from Tahiti and one from Tonga (Wagner 1999). Seven species are recognized on Kaua‘i,
all are single island endemics, with four federally listed as endangered (USFWS 2010)
and the remaining three deserving of endangered status. Wood (2012) recently reported
the extinction of P. knudsenii Hillebr. and hereby reports the possible extinction of P.
kahiliensis, a species that historically exhibited a very narrow geographic range along
with a very low population density. Of the five remaining Kaua‘i species, Phyllostegia
electra C.N. Forbes has no status, but should be listed as endangered as it is only observed
on rare occasions. Phyllostegia renovans W.L. Wagner hovers in numbers of around 50
wild individuals, while P. helleri Sherff, P. wawrana Sherff, and P. waimeae Wawra have
each diminished to less than ten. The Kaua‘i Plant Extinction Prevention Program (PEPP)
and NTBG have prioritized such taxa and efforts are ongoing to search for new individu-
als and facilitate conservation collections. Kāhili Mountain, the holotype locality and only
known location for P. kahiliensis, is characterized by steep jagged ridges and precipitous
side slopes that drop into numerous small headwater drainages dominated by native plant
taxa. Phyllostegia kahiliensis has not been successfully cultivated and it is highly possi-
ble that rough-terrain field surveys around the Kāhili region may lead to its rediscovery.
Material examined. KAUA‘I: steep, moist slope just below the summit of Kāhili Peak, to the
south, 860 m, 4 Jan 1974, Fay 156 (holotype, PTBG; isotype, BISH); Wahiawa Mountains (Kāhili
region), along ridge north of microwave relay towers, 2800–3000 ft elev., 26 Jun 1987, Flynn et al. 2228
(PTBG); above Wahiawa Bog, between TV relay station and first peak on W side of Mt. Kāhili, 855 m
elev., 22 Dec 1983, Wagner et al. 5217 (BISH).
32 BISHOP MUSEUM OCCASIONAL PAPERS: No. 115, 2014

Acknowledgments
For helpful assistance I thank the staff and Trustees of the National Tropical Botanical
Garden, the Bernice P. Bishop Museum, the U.S. Fish and Wildlife Service, the Hawaii
State Department of Land and Natural Resources, and the Smithsonian Institution; much
gratitude to Wendy Kishida and Steve Perlman of the Plant Extinction Prevention
Program of Hawai‘i (PEPP); Tim Flynn and Warren Wagner for discussions on
Phyllostegia; Clyde Imada for helping to improve this manuscript; and Mark Query for
field research assistance.
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HBS Records for 2014