PLANT TAXONOMY
IN THE HAWAIIAN ISLANDS
The Hawaiian flora contains many taxonomically corn l a and poorly
understoodgroups that require further study in the Jield!
David
H. Lorence, Warren L. Wagner, and D e r r a l R. H e r b s t
Taxonomy, or systematics, is an attempt to catalog and study elements
of the living world, both present and past, and to understand the rocesses
that have led to the remarkable diversity of living organisms. At Yeast
million kinds of livine t h i n s have been described and share our biosubere.
Plant taxonm:y (sybtcni;r~icbotany) convey our best understandin; If pattzrrs of n:ltural biological diversity in plant,. Sincc txwnomy is ;, very
funct~onalscience. i t must he tlcuble e n o ~ g hto reflect changes as we ohtnin
new iniormation thst helps us hetter understand the organim, we are st.dying and the relationshipr among them.
It is usef~ilto review thti evolution of ~ l a n tasonomv.
t
which has resulted
in our modern svstems of classification. &lore than 2.000 vears aeo the Greek
pli~losophcr~ h & ~ h r ; i s t u as ,pupil of Aristotle, recognixd thedi?ferenc&
between trees, shruna, and annual, biennial, and perennial herlis. Know11
o Jsccd. stem. and leaf
the "father of hot;~nv. Themhrastuh ;dw u n d e r ~ t ~ ~the
d~ficrcnceshctnccti monochyledons m d dlcotyleduns as well as mnnv other
mf~rphologiral
d~fference\In veqctative and 11%dl feature,, many of these
formed the basis for later systems of classification.
The practice of referring to organisms by descriptive Latin phrase names
known as polynomials (many names) began in medieval times. The concept
of genus, a group of closely related species to which an orgalusm belongs,
dates back to the end of the 17th century, when itwas used i? herbals,
high1 illustrated works about plants considered to have medlclnal value.
?he system of naming living things was simplified considerably in 1753
when Carolus Linnaeus published his Specie~Plantayn$Species of Plants),
a landmark work that contained br~efanalyt!cal descnpttons of every known
species of plant as well as references to earller works. For convenience,
Limaeus introduced a binomial (two-name) system prig both a generic and
a specific name for each plant. In addition to provldlng the first consistent
use of the binomial system, Linnaeus instituted two systems of plant classification, an artificial classification system for the rapid cataloging and
identifying of plants based primarily on the number of floral parts, and the
basis for a natural classification system, that is, one reflecting the actual
evolutionarv relationshios of ~ l a n t to
s each other.
Du&itlic 18th and l~thcenturiesa number of cl~ssification?,terns,
primar~lvdescripti\e in scope, were developed. The publication of Darwin's
Origin q'Species in Id59 had a great impaci on plant systematic?, and the
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concept of evolution began to be reflected in classification systems of the
For the first time it was recognized that species and higher
rGk"Zrived from progenitors (ancestral forms) through evolution
b natural selection. The concept of phylogeny, or evolutionary relations&os of oreanisms to each other, was thus formed. It was to be a most i m ~ o r rani charaseristic of all later .y.tems of cl;irsii~c~tim.
\Ian! ollicr \.lcnk
were subsequently developed to reconcile the nlorph8~logiz41
frxlurch
~ l a n twith
s an evolutionafy interpretation of these-features.
~
ml~rcl!.
Although in the past much systerrtat~crescxch \ r ; l I I A ;~lrnost
upon "class~cal"morphological and anatomic:ll siniil~ritiz\and dil<zrc~i~~..,
modern biosvstematics (biological systema~ic\)nrnv 1 1 : ~at~ its di\r]<lr:~I;I
whole soectium of new tools and technioues for ohvlozenetic intkrnretation
and s o l h o n of taxonomic problems. nibchemich bnGironi quantiii;atwn oi
DNA (genome analysis) and studies of i~roteinmolecules can he med I,]
undersiand relationshbs of soecies to one another. Chemical taxonomv
(chemotawonomy) prohdcs ahlitional data for thc systematist :mJ is u;cful :n
determming the parental spccics in cases of suspertcd hybridiwtion. Uoth
sc~nningand transmission electron microscopy (SliM and TI31)are powerful
tools now widely used in systematic studies, for examplc, examination oi
trichomes (hairs), pollen, and sieve tuhe plastids (storage orgmelles or
little orcans found in vascular olant tissucl. In addition. chromosome number
behavior, karyo& analysis, hybridization, &ogenetics, and
and
breeding systems are aspects of biosystematic studies that provide important
data for understanding plants taxonomically and pbylogenetically. Interdisciplinary collaboration between biologists is alw becoming increasingly
important.
The most modern and widely accepted systems of plant classification
today are essentially based on a synthesis of all available data.
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A HISTORY OF BOTANY IN THE HAWAIIAN ISLANDS
E a r l y Explorers
Because of their isolation. the Hawaiian Islands harhor
a unioue
and
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astonishing flora with a highe; degree of endemism than any comparable
area of the world. About 91% of Hawai'i's flowering olants are endemic
(found nowhere else) (Carlauist 1980: Sohmer and C%stafson 1987:. see
- ~also
-~kanr.>hiro, this vcdunle). TI& iir,t \\'&tern botanist to explore and collect
specimen, in [he 11aus11mArchipr1:ieo ua\ David Selwn in 1779, on Captain
Jimes Cook's third vovaee. an; othkrs followed. most notablv Archihdd
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\lenzie.;, Adelbert ('han%io, Charles (;audichaud-neaupr6, a i d James Macr x . Finallv, a team of sclenti,~. \uth the U.S. t.xploring Expedition commanded b<Charles Wilkes in 1840-1841ment skmonths in the Hawaiian
Islanas miking exten$ive natur3l histury chlections that resulted in the
published de\criptiunh 111' nl:in\ new species. During the same period, the
lslmds were also ri,ited h\ a number o i inde~endenttravelers and naturalists, some of whom collec<ed plants (Kay 1972).
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Earlv Resident Botanists
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'l'he great exploring expeditions finally came to an end in the late 19th
century. 1)escend;mt.; of the earlv misslonary familes subsequently became
Planr Tmmrmr?y\Lorcrlce ef al.
45
interested in natural history and made biological collections which they
sent to scientists in America or Europe.
An im ortant phase began when botanists such as Hillebrand, Mann,
Brigham, Jock, and Forbes went to the Hawaiian Islands and made significant
collections while residing there. William Hillebrand, a German physician and
accomplished botanist, lwed in Honolulu for 20 years and was one of Hawai'i's
most renowned doctors. During his stay in Hawai'i (1851-1871), Hillebrand
explored all the larger Islands and collected numerous herbarium specimens,
sets of which were deposited in the B.P. Bishop Museum in Honolulu, Melbourne, Berlin, and Zurich herbaria. His extensive living collections now
form part of Honolulu's Foster Botanic Garden. Charles Forbes, the first
full-time botanist at the B.P. Bishop Museum, was appointed in 1908. His
many herbarium specimens became the nucleus of the rich Hawaiian collections housed there todav. Josevh F. Rock, who came to Hawai'i in 1907 from
Austria, spent about 12years siud\in$ the flma o i Ilunaii and cnllected
numerous herbarium specimens. . . \ n l m ~thc other early resident naturalists.
Jules Remv, Theo Ballleu, Valdemnr tinudcon, and .John \I. 1.vdyatc
all
.
desenre mention for their contributions.
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Recent Resident Botanists
l k o great stt!dents of the Hawaiian flora have lived and worked in the
Islands for many years. Otto Degener (recently deceased) came to Hawai'i in
1922 and collected extensively. He distributed a large series of duplicate
plant specimens to a number of herbaria world wide. Harold St. John came to
teach at the University of Hawaii in 1929 and has pursued his studies of
Hawaiian plants since then, making extensive collections.
PUBLICATIONS ON HAWAIIAN BOTANY
Existing publications on the flora of the Hawaiian Islands fall into two
main categories: systematic studies, including monographs and revisions,
and floristic treatments (floras). An early example of the first category is
Rock's m o n o m a ~ hof the Hawaiian soecies of the tribe Lobelioideae of
~am~anulac~ae'(.'lohelioids"),
in 1919. Although many tarmomic
studiec on Hawaiian plants exist. a large numher were pubhhed hy hotan~sts
such as E.E. Sherff. who worked exclu&elv with driedherbarium boecimens
and never visited llaw~i'i. On the other hand, several excellent ex:;rnplcs o i
modem biosystematic treatments incorporating field ohscrvation with
morphological, anatomical, cytological, and hybridization data cxkt. \lore
work of this type is badly needed for many Hawarran group*.
The first comprehensive account of the Ilawaiidn flora 3s a whole is
Hillebrand's bloru ofrlrr lluwuiiun Islands (1x88. rc~uhhshedin IOXI).
based on extensive iollections and field observationk AIthough now dated, it
has been used bv generations of students of the Hawaiian flora. Rock's (1913,
reprinted in 1972jhdigenous Trees of the Hawaii? Islands also falls into
the floristic categoly. Degener's Flom Hawaiiensu, begun in 1932, is an
ongoing series comprising some seven volume^ conslst!ng of treatments with
taxonomic keys, descriptions, synonymy, and h e drawngs (see Mill ef al. 1985
for details). Although quite useful it is unfortunate!y not complete. A number of popular works on Hawaiian plants also exlst, mcluding Marie Neal's
In Gardens of Hawaii (1965) and the recently published Plants and Flowers
ofHawaii (Sohmer and Gustafson 1987). the last replete with excellent color
photographs. The forthcomingManua1 of the Flowering Plants of HawaiT,
coauthored by W. Wagner, D. Herbst, and S. Sohmer, 1s in press. The Manual
will not only offer consistent, synoptic treatments with a biological basis for
flowering olant families in Hawai'~but will also highlight and discuss
nroblem& and taonomicallv com~lexeenera a d sogcies erouos. However.
;he rc~rLtrlonof some problems is 6 c y o d the scope h a flo;hr~! trqatment.
:is olmts need to be studied througli 3 combination of field t~h..cn.ntlons,
biosvstematics, and other moderntechniaues as well as a classical taxonomic
nppioach. By callmg attention to these p;ohlems, the authors hope to
\liniulate new interest and research hv tithers.
MAJOR PROBLEMS
The Hawaiian flora contains manv taxonomicallv comolex and ooorlv
understood groups that require furthe; study in the geld. klthougha laGe
number of botanical soecimens have been collected in Hawai'i, there has been
relativelvlittle studvof natural oooulations in the field and few attemots
ro cokdate field r&ults with &ra'from biosystematic studies. One mirjor
~ r o h l e mis that many previous l a r u n ~ m studies
~c
were based entlrelv on
dried herbarium soefiine~s.Therefore. taxonomic entities such as sbecies or
varieties were oft& dcscrihed, with no biological understanding of thc plants,
~
m.,! nierelv
on the hmis of one or a few specimens. In realitv, t h specimens
reoresent stages in a continuous ranee of variation andnot biological
enti tie<. Fieid studies are therefore'necessary to understand u lh;r I > rc,prcr e n t d i n ;I hiological sense. Hahitat disturbances h) feral h n i n l ; ~ l , . h~ltn;,n
nai! it!, ;~nd~nva\ionby alien \peciesare all becoming incre;,%ingl\*i,ucr.,.
S t u r l ~ co ~i pl;tnt ;rnd arlirnal populations in the field and applic:~tion. ~ i
nod ern tr~cI111
,,ucs are cimtrngent on protection olrlletr h:,hi!;~t..
In dJttiori, :1 l n r ~ einflux ofcollections made over the recmt \c:lr, i,
vieldine soecimens wiiich are critical to an understanding of oroblim erouos.
W!wr cdic.a!msrepresent new distributional rccords 6 r islknds ;tr~d&i
inrludc 11cu undescr:bed taxa. Since the existing 1:rxonomic and flor~htiz
literature is scattered and varies reatly in scope, quality, and consistency,
it is obvious that a changing, mo ern flora is required to incorporate and
synthesize all the information.
Another maior oroblem in olant taonomv in Hawai'i todav is that more
trained taxonom'ists'and studenk, hoth at the L.rxltratc and undergraduate
levels, are needed. Fund~ngfor pc:,t.nni.l. :I\ \\c:I ar for research e uipment,
herbarium suoolies. and field u~ork.i \ ;I ni:tr~>rwnmaint. Manv of i e existing facilities &id idrastructures :,r< ~ . w r . l i l ! ; ~ d q u a : e(for exahple, those
ht;:nical Garden), hul an
at the B.P. Bishop Museum :,nd I'.laik 'I'rtq~ir;~l
active research program always requires some expansion.
t
RECOMMENDATIONS
It is suggested that available time :and resources be focused on field
studies and 3n:ilyses of olanls with a~ecifictaxonomic oroblems. The result.;
will not only contribute-to conservaiion, but also will drovide essential
data on the btology, evolution, and relationships of plant taxa. Modern
Plant Taronomy \Loreme
el 01.
biosystematic revision5 and mt~nogr:~phs
dealin with Hawaiian plants arc
~ l du l this type. . ore funding for plant
few, and further e f f o r t s k h i ~ ~ bc
taxonomy, holh rescarcli d n d pcr,onnel, should be sought.
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Important References: Herbaria
The herbarium is an extremely important reference for conservationists a
well as taxonomists. It is apermanent data base and reposito for voucher
specimens of the plants being studied and is important as a rezrence collection for determining and verifying plant identity, thus serving as the basis
for scientific studies and publications. The herbarium is also an important
reference at the State level (for example, the herbaria of the B.P. Bishop
Museum, Pacific Tropical Botanical Garden, University of Hawaii, and
National Park Service), as the specimens yield information on the plants'
distribution ( ast and present), habitat, range, phenology (flowering and
fruiting timesy, and morphology.
Important References: Literature
Bamam, E.B. 1933. Ma11ua1ofHowailan Afosser. Bishop Muscum Bulletin 10. Bishop
Museum Prcss, Honolulu.
Barrmm, E.B. 1939. Supplement to manual of Hawaiian moss=. Bernice PatroltiBisltop
Museum Occosionol Papers 15:93-108.
Carlquist, S. 1980. Hawaii: A Natrrral Hislor).. Pacilic Tropical Botanical Garden, Lawai,
Kauui, Hawaii.
Hillebrand, W.F. 1981. FlomoJlRe Hawoiiorr Is10,lds. Luhrecht and Cramcr, Monticcllo,
New York. (Facsimile of the 1888 edition.)
Kancshiro. K.Y. lthis volumel Uniaueness of Hawili'i's hiota.
Kay, E.A. 1572. Hawaiiannatural history: 1778-1900. Pp. 608-653 IN E.A. Kay (ad.), A
Natural Hist- ofthe Hawaiian lslorndr Sdecled Readi!rp Univ. Press of Hawaii.
Honolulu.
Magnusson, A.H. 19%. A catalogue oI the Hawaiian lichens. Arkiv. for Botanik
3223-W.
Mill, S.W., W.L. Wagner, and D.R. Herbst. 1985. Bibliography of Otto and Isa Degencrs'
Hawaiian floras. Taron 34(2):229-259.
Ncal, M. 1965. 1,) GardensofHowaii. Bishop Museum Special Publ. 50. Bishop Museum
Press, Honolulu.
Rock, J.F. 1974. 77ze Irzdipr,,mcs Trew of the I f m i i o n Idmds. Pacific Tropical
Botanical Garden, Lawai, Kauai, Hawaii, and Charles E. Tuule Co., Rutland, Vermont
and Tokyo, Japan. (Reprint of 1913 edition.)
St. John, H. 1973. Li,~torzd S u n l n l o ~of the Flowering Plants in the Hawaiian Is(ands.
Pacific Tropical Botanical Gardcn Memoir 1. Lawai, Kauai, Hawaii.
Sohmer, S.H., and R. Gustafson. 1987. Pla~zlsand F l o w n ofHawaii. Univ. Hawaii Press,
Honolulu.
Wagner, W.L., D.R. Herbst, and S.H. Sohmer. In press. Ma~tsoloftheF1o~rrrir~gPla~zt.r
of
Hawai'i. Bishop Museum and Univ. Hawaii Presses, Honolulu.