Toward an Improved Classification of Lauraceae

10 Pages·1996·7.1 MB·English

by  Henk Van Der Werff

TOWARD
AN IMPROVED
Henk and
van der
Werfp-
H. Richter^
G.
CLASSIFICATION OF
LAURACEAEi
Abstract
Published suprageneric classifications of Lauraceae and the characters used in these classifications are briefly
reviewed. concluded that androecial characters such as number of stamens and number of anther cells are
Il is
often variable even within genera and that these characters should not be used in a classification of Lauraceae.
As a step toward an improved classification, Lauraceae are divided into two subfamilies, one consisting of
first
Cassytha. the other including all other genera. The latter group is divided into three tribes, the Laureae, Perseeae,
and Cryptocaryeae, based on characters of wood and bark anatomy and inflorescence structure.
Lauraceae form a large, predominantly tropical recorded from Ecuador, while currently 11 spe-
family of trees and shrubs, with the exception of cies are known from that country. More intensive
The
Cassytha, an herbaceous parasite. family collecting will hopefully correct this lack of
is
best represented in the American and Asian trop- knowledge. *
number
and has also a rather large of species Lauraceae have, with a few exceptions, trim-
ics,
in Australia and Madagascar, but poorly rep- erous flowers. Flowers bisexual or unisexual.
is
resented in Africa. About 50 genera are currently There are two whorls of three tepals; the whorls
2500—3000 and some
recognized, with species. are usually equal in size shape, but in
Economically, Lauraceae are an important cases the whorls are unequal. the whorls are
If
Many
group. species yield high-quality timber, unequal, the outer whorl usually smaller than
is
others spices or aromatic and Persea amer- the inner one, although the reverse can also be
oils,
icana Miller cultivated worldwide for edible the case. Flowers have four whorls of three sta-
is its
fruits. mens, but in most genera, one, two, or three
New
The
Ecologically, Lauraceae are, in the World, whorls are reduced to staminodia. anthers
a very important group. They are present in wet open by two or four valves. The ovary generally
is
forest at any elevation (from sea level {o paramos) superior, with one locule and one ovule, and the
common
and are frequently the most or one of a one-seeded berry, either free on a
fruit, sits
common
the most tree families, especially in the pedicel, partially enclosed by persistent tepals
is
foothills and at middle elevations of the Andes. or the receptacle, or is entirely enclosed by the
In spite of their importance, Lauraceae are, in receptacle.
and numbers,
respect to classification species
known. Our knowledge
poorly lack of of species
Lauraceae
Classification of
numbers and distribution no doubt related
is to
many
the fact that species are tall trees with Strictly speaking, there is no lack of suprage-
small, inconspicuous flowers, difficult to locate neric classifications of Lauraceae. All have in
common
and to collect. This is clearly shown by a recent one characteristic: they are not widely
We
floristic treatment (Australia: 115 species, of accepted. will present a brief review of these
which 46 were new, Hyland, 1989), recent revi- classifications and the main characters used
list
sions {Nectandra: 114 species, of which 33 were in making them. The position of Cassytha in the
new, Rohwer, 1993a; Pleurothyriurn: 40 species, different classifications will not be discussed;
it
of which 20 were new, van der Werff, 1993), and always separated from the other Lauraceae be-
is
the fact that in the most recent monograph of An- cause of its herbaceous, parasitic habit, and we
iba (Kubitzki, 1982) not a single collection was place in own subfamily, the Cassythoideae.
its
it
John Myers assisted in the preparation of the figures. We thank Tom Wendl for critical comments on an earlier
'
version of the manuscript.
^ Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, U.S.A.
Holzhiologie und Holzsehulz, Bundosforschungsanstalt Forst- und Holzwirtschaft, LeuschnerstraBe
^ Institut
ftir fiir
2050 Hamburg Germany.
91, 80,
409^18.
Ann. Missouri Bot. Card. 1996,
83:
) :
410
Annals
of the
Garden
Missouri Botanical
Characters Used Meissner
in
Nees
Suborder Laurineae
(1836) Classification
1
Suborder Gyrocarpeae, excluded from Lauraceae
2)
Leaves deciduous evergreen. 3) Suborder Cassytheae, Cassytha
1) vs.
Laurineae:
Inflorescence umbellate or glomerate.
2)
No
A. Inflorescence paniculate, racemose or spicate. involucres.
a) Inflorescence umbellate, involucrate.
Tribus Perseaceae:
Inflorescence glomerate or subracemose,
b)
Flowers hermaphrodite. Stamens Cupule present or lacking.
9.
from
arising perulate buds.
Staminodia well developed.
2) Inflorescence paniculate. 4-celled anthers, 6 genera
1)
Anthers opening 2) 2-celled anthers, 6 genera
3) apically.
Oreodophneae:
Tribus
Anthers opening below
3) tip, equal.
Flowers
unisexual, cupule present or lacking.
Outer
anthers
3) petaloid.
a) Stamens free, 4-celled, inner 3 extrorse; 7 genera
Anthers with
3) distinct filaments. {Ocotea Nectandra, Pleurothyrium)
S.I.,
4) Fruits covered by perianth tube. b) Stamens free, 4-celled, all introrse, 2 genera
(Sassafras, Sassafridium)
4) Fruits not protected by perianth tube.
c) Stamens free, 2-celled, inner 3 extrorse; genus
1
Staminodia lacking present, without
5) or,
if
{Goeppertia)
capitate apex.
Stamens
d) flowers hermaphrodite; 2 genera
fijsed,
5) Staminodia with triangular head. {Symphysodaphne Synatidrodaphne)
,
Tribus Cryptocaryeae
Tepals
6) entirely persistent
Flowers hermaphrodite, enclosed
fruits in calyx.
cup
7) in a solid
Flowers 4-merous. Adenostemum,
excluded.
1)
spreading, not thickened
7)
Flowers
2) 3-merous, 2-celled. 10 genera, including:
Tepals deciduous
largely
6) Cryptocarya, Aiouea, Ampelodaphne
7) Truncate basc,only, persistent. 3) Flowers 3-merous, capitate, 2-celIed, stamina
monadelphic Misatuheca.
deciduous.
7) Flntirely
4) Flowers 3-merous, 4-celled, stamens free. 4 genera
Figure* 1. Main characlertj used in Nees's (1836) clas- B. Flowers umbellate or glomerulate. Involucrum present.
Tribus Litseaceae:
silicalion.
Subtribus Tetranthereae. Anthers 4-celIed, 5 genera
Subtribus Daphnidieae. Anthers genera
2-celled; 5
It has been suggested that Cassytha is closely Figure 2. Main characters used in Meissner's (1864)
related Cryptocarya (Rohwer, 1993b); however, rlassifualioii.
to
main
the eharaelers discussed paper
in this (in-
flor(^scence structure and wood and bark anato-
my) will not elucidate the relationsips of Cassy- Kostcriiians (1957) published a new classifi(*a-
The hy Nees One
tha. classifications (1836; Fig. tion, in wliich he recognized five tribes
1), (Fijj. 7).
Meissner (1864; Fig. 2), Benthani and Hooker tribe was recognized by its involucrate inflores-
Mez
Pax
(1880; Fig. 3), (1889; Fig. 4), (1889; cence, the other four non-involucrate tribes by the
and Hutchinson One
Fig. 5), (1964; Fig. 6) are all deveIopin(Mil or lack of cupules. tribe was rec-
l>ased on the following characters: infl()res(;ence ognized by a complete absence of a cupule ex-
(for
number
paniculate versus umbellate; of anther ample, Pcrsca aiu] Bcilschmiedia)^ the second by
number
cells (2 vs. 4); of stamens; fruit enclosed the presence of a more or less cup-shaped cupule
in perianth versus seated in a cup or free; and {Ocotea, Nerfandra), the third by having the fruit
flowers unisexual or bisexual. These classifica- almost com[)l(^tely enclosed by the cupule [Cryp-
tions are strongly influenced by the choice of the tocarya, for example), and the fourth by having a
most important character, and differences be- truly inferior ovary and the entirely enclosed
fruit
tween the classifications are a result of such by the hy|>anthiuni (only Hypodaphnis). Further di-
choices and based on num-
are not iu»w or belter data. vision within the tribes primarily based on
is
For instance, Pax used 2- versus 4-celled anthers ber of anther cells. In comparison with the contem-
Mez
as the most important character, while and porary classification of Hutchinson
(1964),
Nees
used inflorescence paniculate versus race- Kosterinans's classification clearly sup<^rior, not
is
None
mose. of these authors defends or cxplai because the characters used lor the classification
his determination of the importance of the char- are sounder, but because he knew the Lau
acters, and all classifications are in some aspects w^elL Thus, he excluded a number of weak genera
confusing. Several of these classifications include recogniz(Ml by Hutchinson, and avoided errors that
g(nu^ra no longer recognized or which were based Hutchinson, less experienced with l<auraceae,
on faulty diagnoses, but such details are of his- made. Kostcrmans s classification has fi>und general
torical interest oidy. acceptance (hiring the last 30 years, although sev-
Volume Number 3 van der Werff & Richter 411
83,
Lauraceae
1996
Classification of
Mez
Bentham and Hooker
(1880)
TRIBES
3
Herbaceous
parasitic vine; inflorescence indeterminate
Cassytheae
Stamens whorl opening
Perseaceae. of
1) III
Laureae
Shrubs or inflorescence determinate
trees,
extrorsCj with 2 basal glands,
Inflorescences paniculate, exinvolucrate Perseeae
inriorescences lax, pedauncu late. Anthers of outer two whorls 2-celled or sterile
fl
1
two
Anthers of outer whorls 4-celled
Anthers included perianth.
2-celled. Fruit in
a)
Inflorescences racemose, involucrate Litseeae
b) Anthers 2-celied. Fruit with without cupula.
/
Anthers
2-celled
number
subdivided by of stamens.
Anthers
4-celled
Anthers 4-celled. Fruit with/without cupule
c)
Figure 5. Main characters used in Mez's (1889) clas-
number
subdivided by of stamens.
sification.
stamens opening
Litseaceae. Trees or shrubs. All
2)
Inflorescence dense, short,
introrse. eral workers have pointed out difficulties with ge-
subsessile (except Sassafridium).
and (Hyland,
neric circumscription classification
Inflorescence lax or imbricate bracteate.
a) - 1989; Rohwer 1991; van der Werff, 1991).
et al.,
Inflorescence umbellate or capitate, included
b)
Richter published the results of his study of
(1981)
number
an Subdivided by of
involucre.
in
wood and bark anatomy of Lauraceae, in which he
anther
cells.
One
found three large groupings of genera (Fig.
8).
of the groups corresponds with the tribe including
genera with involucrate inflorescences, but the oth-
Cassytheceae. Leafless vines.
3)
er two groups have no counterpart in the existing
&
Figure 3. Main characters in Bentham Hooker's classifications. For instance, Richter placed Cryp-
(1880) classification.
same
tocarya and Beibchmiedia in the group, while
Kostermans occupy very
in s classification they dif-
ferent positions.
Rohwer
The most recent classification by
is
r
He main based on
(1993b). recognized two groups,
PAX
inflorescence type, one involucrate and one exin-
Stamens
9
were based on and
volucrate. Further divisions fruit
Stamens Extrorse floral characters, but because these characters were
III
Stamens 3
Anthers
4-celled
Hutchinson
Flowers
unisexual
Stamens
Introrse
III
Anthers
4-celled
Inflorescence
more
2 or flowers
enclosed in bracts
in involucre
Leafless-Cassytha
Anthers
2-celIed
flower each
Anthers 2-celled 1 in
involucre
Leafy
Fruit enclosed in
calyx tube
Stamens Extrorse All stamens Introrse
III
Anthers
2-celled
Fruit not enclosed
/
Inflorescence not
in calyx tube
enclosed in bracts
Stamens 3 Stamens 6 or 9
All anthers introrse
Anthers
4-ceIIed
Receptacle shallow Receptacle deep cup-shaped Anthers extrorse
III
Figure 4. Main characters used in Pax's (1889) clas- Figure 6. Main characters used in Hutchinson's
(1964) classification.
sifiralion.
412
Annals
the
of
Garden
Missouri Botanical
Hypodaphflii Tribut H)rpodaphn«a« Ko«1«rm
I
I
I
Clinoit*mon
Tribus P«ri»«ft» Mar
Figure 7. Classification uf Kusleniiaiis (1957). Ut'pniited with permission.
used with some hesitation, no formal classification STKEiNCiTH of Cjiaractkks Uskd Pibusmki)
in
was proposed. Keys genera were recently
to pul)- CLASSIFICATIONS
lished hy van der Weiff (1991; for genera of the
New A
World) and Rohwer (1993b; for genera world- robust classification demands that the cnar-
cl
'
wide). acters used are reliable; that there are no or few
is,
Volume Number 3 van der Werff & Richter 413
83,
1996 Lauraceae
Classification of
s
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414
Annals
the
of
Garden
Missouri Botanical
Genem
number
Tal)U* 1. with variation in uf antlier cells.
Aiouca
normally nine 2-(elled, rarely six or three 2-eelle(l
A
n iba normally nine 2-eelled, rarely six 2-eelle<l
Aspidostemon
either six 2-eeIl(*(l or three 2-eene(l
Bt'dscliniirdid norniallv nine 2-eelle(l. rarelv six 2-eelhMl or nine l-eelh^l
Ca odaph
r) n ops is normally nine 4-eelletl. rarely nine 2-eelle(] or six 2-eelle(l
Cassylha normally
nint; 2-(elle(_K larely six 2-celled
Cinnamomum
normally nine 4-celled, rarely nine 2-eelIed
Endidudra
normally three 2-eelled, rarely six 2-eelled
Endlicheria normally nine 2-eelled, rarely six 2-eelled three 4-eelled
-I-
+
Kubilzkia nine 2-celled or six 4-eelled three 2-eelled
Persea normally nine 4-eelIed, rarely nine 2-eelled or six 4-eelled
+
three 2-eelled
Potmneia
normally
Auir 2-eelled, rarely four 1-eelled or two -celled
1
Urhanodi'fidron norniallv nine 4-celle(], rarelv nine 2-eelhMl
exceptions to the coiulitions characteristic for a <;iv- slamcns and nuniher of anther cells on each sta-
An
en
taxon. analysis of the characters used niosl men. Possihle variation of these characters can, of
frcquently in the generic and suprageneric classi- course, best he studied in <^vnerd defined by sonie-
1
Lauraccae how
fications of will allow us to estimate tiling otlu^r than these androecial characters. This
these taxa arc foundtMh
W(,'ll variation considcrablf* (Table For instance,
is
1).
frecjuently used character among
refers the
to in- the neotropical speckles of Caryodaphnopsis,
florescence. plirased ways
It is in slightly different defined by having opposite heaves and unequal
t(^-
the various Nees
\n <'lassifications. (1836) anrl pals, are species with nine 4-celli'd stamens, nine
Mcissner
(1864) contrasted undxdlate versus pa-
2-celled stamens, and 4-celled stamens plus
six
niculate infloresc(;nce, with and with<»ut an invo- Polw
three staminodia. Likewise, most species o[
lucrum; Hutchinson
(1964) stressed the i)rcsence mem,
defined by having dimerous have
fiowers, four
or absence of brads; Koslcrmans decussate
(1957),
2-cellcd stamens; few have stamens
a four 1-celled
bracts; Roliwcr (1993b) mentioned ^^some kind
ari<I and one
species, as yet undescribed, has two 1-
of involucre." Based on the senior authors expcii-
cvWcd
stam<uis. Neotropical species placed in Per-
ence, the character states of involucrate, racemose
sea mostly have nine 4-celled stamens, some
])ut
versus exinvolucrale, paniculate inflorescence are
have nine 2-celled stamens or six 4-celled and
we know
reliable; no genera which both kinds
in
(»f three 2-cellcd or six 4-ccllcd and tliree staminodia.
of inflorescence are repn^sented, and we accept the
Looking
the geiuM-a defined by 2-celled stamens,
at
inflorescence differences as reliable g(^neric char-
the similarity between most Aiouea species
(2-
The
impoilance
actcrs. of inflorescence types
in
th( and Cintuimomum
celled) and
(4-celled) striking
is
classification of Lauraccae will be (fiscusscd further
seems more
than convergence; however, Aiouea
in this aili(de.
lexairix van der Weiff very similar some sym-
is to
Tlie next set^ of frequ<>ntly us«h1 charactei-s are
p.^t.ic Ocotea species, as are A. hmdelliana Allen
those of the androecium, number
the of
i.e., fertile
and
A. coslaricen.sLs (Mez) Kostermans (van der
Rohwer A
Werff, 1987a, 1988;
al, 1991). similar
et
situation found Endlicheria Some
is in (two-celled).
Table "Genus" which
2. pairs in apparently closely
species are strikingly similar to
''^ '^'^ /?//oJo.s/e-
related species or species groups are placed
in 'different
monodaphne
or Ocotea specics (Rohwer
genera due to generi<'eircumseri])ti()nl)y anther mini- et al.,
cell
A
1991). third g<Micric pair formed by Mezilaurus
her. is
^
-—
(2-celled) and Williamodendron (4-celled); species
4-<:elle<l 2-eelle(l ol WiUianiodendron were initially described as Me-
zilaurus (van der Werff, 1987), but were subse-
Ci/inaniomuni
Al
loiiea
&
Tcmmodaphne qu<Mitly recognized as a distinct genus (Kubitzki
CituKifUDinuni
A
Ocotea Aiouea Richter, 1987). h'w other examples are presented
Ocotea On
Endlicheria in Table 2. the other hand, there are also 2-
Rhodostemonoddphne
Endlicheria
celled genera do have
that not a 4-celled counter-
Williamodendron
Mezilaurus
such
part, as Cryptocarya, BeiLscluniedia, Aniba,
Litsea Lindera
and These
Licaria. (»xani[)les indicate that the an-
Parasassafras
Sinosassafras
dnxM'ial characters often vaiy within g(*nera and are
Number & 415
Volume 3 van der Werff Richter
83,
1996 Lauraceae
Classification of
unreliable characters in classification at generic paper is a more natural classification at the su-
acknowledged
and higher prageneric level; that this will
levels. is
it
The only character of the gynoccium frequently not immediately lead to monophyletic genera, or
used the degree which the fmit covered by to easier identifications,
is to is
—
hypanthium from no cover and exposed
the fully to
a completely ovary and the fmit fused with
inferior
OuTLOOK FOR A CLASSIFICATION
PlIYLO(;KNETIC
the hypanthium. In most genera this character con-
is
exceptions (Hcur Ocotea, which includes spe- As has been discussed, the e^xisting classifica-
stant; in
The
with pronounced cup-shaped cupules and spe- tions are largely based on floral characters. an-
cies
genera
with very small, platelike cupules. In general droecial characters vaiy frequently within
cles
main
though, the gynoecium character promises to be use- and are therefore a poor choice as characters
The
ful in gtuieric and supragcncric classifications, be- for a generic and suprageneric classification.
emphasized by Kostermans
gynoecial character
cause of its constancy at the generic level.
were attempts order the does not vary within genera and holds more prom-
Earlier classifications to
taxa being studied and were, in fact, frequently ise. However, the classification based on this char-
A
keys translated into a hierarchical system. clas- acter differs gready from the generic groupings us-
was a system enabling one make iden- ing wood and bark anatomy.
sification to
tiflcations, and if that goal was met, the classifica- It seems unlikely that a thorough reexamination of
was acceptable. and characters will yield data with whi(*h
tion floral fruit
More recently, the idea that (dassifications a more robust classifit^ation can be constructed. In-
new
should relationships and evolution of the corporating data sets in building a classification
reflect
taxon be classified has found wide acceptance. looks like a more promising approach. Such an ap-
to
between
Whether or not a phylogenetic (classification is proach requires extensive collaboration par-
A
such
helpful in the identification process is less impor- ticipating specialists. few^ years ago, a project
important be aware of the dual pur- was proposed and initiated by B. Hyland and the se-
tant. is to
It
—
DNA
pose of a classification on the one hand a path nior author, and will incorporate data from stud-
to identification, on the other a reflection of tlie ies, wood and bark anatomy, leaf oils, leaf venation
phylogeny. For purposes of identification, the an- and leaf anatomy, pollen, inflorescence
cutic:les, fiuit
droecial characters are very useful because they types, and the traditional flower and fruit morphology
On
new
well defined and readily observed. the oth- into a classificatiim.
er hand, characters such as number of stamens or The published results of the study of wood and
number of anther cells are variable in several gen- bark anatomy by the junior author (Richter, 1981),
This can only be observed in genera that can and the senior author's observations of inflores-
era.
Lauraceae
be defined by other characters. For instance. Car- cence structures, both indicate that the
Wood and
yodaphnopsis can be recognized by having oppo- divided into three groups of genera.
leaves and strongly unequal tepals; also has bark features employed are of an exclusively qual-
site
it
very distinct wood anatomical characters. Within itative nature, quantitative characters being exclud-
Caryodaphnopsis are species with nine 4-celled, ed as less reliable for their intrinsically high van-
nine 2-celled, and six 2-celled stam^^ns. Other ation. They were selected and weighted in a
genera, for example, Ocotea, lack non-androecial furu^tion of their diagnostic value (identification)
characters {Ocotea defined by having nine 4- and discriminatory power (classification) within die
is
The
celled stamens, with the cells in two horizontal specific context of Lauraceae. set of secondar)'
rows), and species that resemble Ocotea very xylem characters includes primarily diose relating
parenchyma morphology,
closely, but with 2-celled instead of 4-celled sta- to axial distribution, fiber
mens, are placed in different genera (van der inorganic compounds, and vessel morphology. Sec-
Werff, 1988; Rohwer et ah, 1991). Genera such as ondary phloem characters considered as highly di-
CaryodaphnopsLs, whose species share several agnostic and discriminating refer mainly to me-
non-androecial characters, can be expected be chanical tissues, presence versus absence and
to i.e.,
monophyletic, but genera such as Ocotea, whose morphology of phloem fibers and sclereids. These
species only share androecial characters, are not features were employed both in the positive (pres-
Group
likely be monophyletic. Problems with classi- ent) and negative affirmative (absent) sense.
to
fication of Lauraceae exist at two levels: there is definitions are never based on any single feature,
a need for better defined, monophyletic genera, but on a combination of lead characters supported
and a need for a phylogenetic classification at the by secondary features of lesser diagnostic and/or
The
suprageneric level. focus of the rest of this discriminatory value.
416
Annals
of the
Garden
Missouri Botanical
Figure 9. Inflorescence types of group
1.
In the following, observations on inflorescence racemose inflorescence; each flower has one brac-
lypes are described and complemented by evidence teole at the base of the pedicel. Frequently, the
derived from wood and bark
structure: inflorescence axis shortened, with the
is inflores-
A
number
1. Tribe Laureae. of genera have a cence appearing umbellate. The inflorescences are
Volume Number 3 van der Werff & Richter 417
83,
1996 Lauraceae
Classification of
Figure Inflorescence types of group 3
11.
group
Figure 10. Inflorescence types of 2.
renchyma and the ubiquitous presence of septate
Phloem
(secondary xylem). fibers constitute
fibers
often protected by a number of bracts (decussate or part of the secondary phloem of nearly all taxa at-
altemate). This group, with some modifications, has tributed to this group except some species oiAniba,
I
been recognized in nearly all classifications. It in- Licaria, and Ocotea (Richter, 1981, 1985).
The
eludes genera such as Litsea, Lindera, Ldurus, and 3. Tribe Cryptocaryeae Nees. third group
±
cymose
instance formed by genera with a paniculate-
Sassafras, for (Fig. is
9).
In terms of wood and bark structure, the group inflorescence. At glance these inflorescences
first
much
characterized by the absence of marginal paren- look like tliose of group 2, but the ultimate
is
The
chyma and, in most instances, of septate fibers. divisions are not strictly cymose. lateral flowers
Conversely, phloem fibers are always present. Fur- of a "cyme" are not (juite opposite, and flowers can
ther subunits can be recognized, for example the appear individually placed along an inflorescence
genus Sassafras on account of accentuated axis. The placement of bracts along the pedicels is
its
growth ring structure, unique in Lauraceae and re- variable in this group. Sometimes only one bract is
fleeted in both secondary xylem ("ring porous'"") and present, sometimes two alternate or (sub)opposite
phloem (distinct layering by early and late formed ones; further observations are needed. This group
includes such genera as Beilschmiedia, Cryptocar-
tissue
strata).
2. Tribe Perseeae Nees. This group has a pa- ya, Endiandra, Potameia, and Triadodaphne (Fig.
The
niculate-cymose inflorescence. branch-
initial 11).
Wood
ing of the inflorescence is paniculate, w^ith alter- and bark structure supports this circum-
assem-
nate or opposite branches, while the flowers are scription of the Beilschmiedia/Cryptocarya
The cyme number
arranged in cymes. lateral flowers of a bly. All taxa share a of distinctive features,
are opposite. At some point along the ped- such as the presence of marginal parenchyma, non-
strictly
two opposite bracts are present, frequently septate fibers with conspicuously bordered pits, and
icel,
near the middle, but sometimes near the base. In- exclusively simple vessel perforations in the sec-
phloem
eluded group are most neotropical genera ondary xylem. Conversely, in the secondary
in this
combines
Ocotea, Nectandra, Aniba, Licaria, Pleuroth- the lack of fibers with characteristic
(e.g.,
yrium) and some neotropical/Asian genera sclereid formation.
(e.g.,
Persea, Cinnamomum, Phoebe, and Dehaasia) (Fig. As far as wood and bark structure is concerned,
accommodated
can be
not taxa satisfactorily in
all
10).
Cinnamomum
Wood
and bark structure depicts a group of gen- the three groups described above.
era characterized by the absence of marginal pa- and Persea, for instance, appear to be transitional
418
Annals
the
of
Garden
Missouri Botanical
between Group 1 and Group 2, with closer affinities types. Although not all f^enera ('an be placed in our
to the latter. Similarly, Mezilaurus (including Cli- proposed tribal groupings (data are not yet avail-
nostemon), an easily defined and recognized taxon, able for some small genera and some genera have
shares diagnostic bark characters with Group 3 and small, few-flowered inflorescences, making an
In-
wood
diagnostic characters with Group 2. Other, t<*rpretation of the inflorescences difficult), the fact
mostly small genera with a very distinctive wood that two greatly different sets of data support this
and bark structure do not well with any of the classificati<ni makes this the best classification at
fit
three groups, though certain affinities can be rec- hand, and the one to b(^ tested when additional data
ognized, for instance, in the (^ase o{ Caryodaphnop- become available.
Eusideroxylon/Potoxylon, and Ilypodaphnis with
sis,
Group 3, oi Aspidostemon and Chlorocardium with Literature Cited
Group and o( lieadaphne with Group &
2, 1. Beiitliain, G. D. Hooker. 1880. Laurliieae. Pp. 146-
J.
&
Biogeograpliically, this division In three groups 168 in G. Benthani D. Hooker, Genera Planlarum,
J.
Reeve, London.
genera more du vol. 3. b.
OIf logica the generic nices
is ui allic
1 1
Hutchinson, 1964. The Genera of Flowerine Plants
J
. I. 1 ./. . rri T J.
proposect ni earlier classiiicalions. Uie Laun^ac, n
/n- n^
^ r\ r
^ (l)icol. vli e(iionae)\, voli. i Llarencti on IVess, Uxfonl.i
1.
racemose
with inflorescences, are best represented,
A
Hyland, B. V. M. 1989. revision of Lauraceae in Aus-
at the generic level, in the Northern Hemisphere tralia (exeluding Cassytha). Austral. Sysl. Bot. 2: 135-
[Laurus, Sassajras, Umbellularia, Parasdssafnis, ^*^*^-
A
Comm.
V)57. Lauraceae. For
".
Lindem, ^^^^^^'^^^^^'^ J;
Litsea, Neolitsea). although several gen(M-a ^';
Hes 1—64
57"
Inst
are well represented in the Asian and a (<>w
tr..i)ics
Mon-
Kuhilzki, K. 1982. Laurac-,-ae: Aniha. Fl. Neotrup.
extend into Australia. Most genera with unisexual
1-84.
ogr. 31:
&
flowers (about belong group, and H. G. 1987. Williamodendron Kuhitz-
10) to this in- Ricliter.
it
&
new
cludes genera with four and two anther The ki Riehler, a genus of neotropieal Lauraceae.
cells.
49-89.
Bot. JaluL. Syst. 109:
Perseeae are mostly neotropical, with the genera
in
Meissner, G. F. 1864. Lauraceae. In: A. de Candolle (ed-
Persea-Cinnarnomuni-Phoehe
the com{)lex also
Prodromus 1-200.
itor), Sysleniatis Naturalis 15:
present in troj)ical and subtropical (Northern Hemi- Mez, C. 1889. Lauraceae Americanae. JahH). K()nigl. Bot.
1—556,
Gart. Berlin
sphere) Asia; Ocotca also present in Africa and 5:
is
Nees von Esenlteck, C. G. D. 1836. Syslenia Lauri-
F.
Madagascar. Only three genera group have
in this
naruni. Sunitihus Veitii et socioruni. Berlin.
Um'
unisexual one OcoUa,
flowers; of these, also
in-
&
l.a;^?" LauracraeriV^i()n2fr,7r
Engler
many
eludes species with bisexual flowers. Both
K. Prantl (editors), Die natiirlichen Pflanzenfiimilien,
genera with 2-celled and 4-celled stamens are pail vol. III. Kngelmann. Leij>zig.
Kictiter, H. G. 1981. Anatomie des sekundaren Xylems
The
ol this group. Cryptocaiyeae are best repre-
und der Rinde der Lauraceae. Sonderh. Naturwiss. Ver-
sented in the Southern Hemisphere {Cryptocarya,
Hamburg
1-148.
eins
5:
Beilschmiedia, Endiandra,
Potanieia)^ but are also
Wood
1985. and hark analomv Lauraceae
of IL
.
present in the Nortliern Hemisphere. All g<*nera in Licaria Auhlet. L\WA Rull. n.s. 6: 187-199.
group The Roliwer. G. 1993a. Lauraceae: Nectutuhd. Neotrop.
this hav(^ bisexual flowers. core genera J. Fl.
Monogr
60: 1-3:52.
{Cryptocarya, Beilschnuedia, Endiandra, Potameia,
366-391
1993b. Lauraceae. Pp. K. Ku-
in
.
Triadodaphne) have 2-c<dled stamens; Ilypoda-
all
Rohwer The Fam-
hitzki. J. {,. <S V. Bittrich (editors),
phnis, Eusideroxylon, and Poloxylon, provisionally ilies and Genera of Vascular Plants IL Springer- Ver-
placed in this group, have 4-celled anthers. lag, Berlin.
&
Two
H. G. Hichter H. van der Werff 1991.
Although not genera can be ,
all satisfactorily
new
genera Lauraceae and
of neotropical critical re-
placed in Richter^s system, avoids several anom-
it
marks on the generic delimitation, Ann. Missouri Bot.
alies present in Kostermans s classification, such as Gard. 78: 388-4-00.
treating Endiandra, Mezilaurus, Persea, and Werff, H. van der. 1987a. Six new species of neotropical
401^12.
Lauraceae. Ann. Missouri Bot. Gard. 74:
Beilschniiedia as Close
s cl re latiives
A
1987b. revision of Mezilaurus (Lauraceae).
.
Thus, the two recent classifications of Lauraceae
Ann. Missouri Bot. Gard. 74: 153-182.
iliffer greatly from one another. Kost(M-mans s (1957)
1988. Eight new species and one new combi-
.
classification is based mainly on one character only, nation of neotropical Lauraceae. Ann. Missouri Bot.
Gard. 402-419.
75:
gynoecium
the position of the relative to the hy-
A
1991. key to the genera of I-auraceae in the
.
panthium, while Richters
(1981) classification
is
New
World. Ann. Missouri Bot. Gard. 78: 377-387.
based on seveual characters from bark and wood
A
1993. revision of the genus Pleurothyriuni
.
and is supported by observations on inflorescence (Lauraceae). Ann. Missouri Bot. Gard. 80: 39-118.