Table Of ContentA révision of Weinmannia (Cunoniaceae)
in Malesia and the Pacific. 1. Introduction and
an account of the species of Western Malesia,
the Lesser Sunda Islands and the Moluccas
Helen C.F. HOPKINS
Laboratoire de Phanérogamie, Muséum national d’Histoire naturelle,
16 rue Buffon, 75005 Paris, France.
Masons Arms, Hutton Roof, via Carnforth, Lancashire, LA6 2PE, U.K.
With the collaboration of J.C. BRADFORD
Missouri Botanical Garden, P.O. Box 299,
St Louis, MO 63166. U S A.,
and Washington Universîty, St Louis, U.S.A.
ABSTRACT
About 40 species of the l.irgcly tropical, montane genus Weinmannia occur
in Malesia and the Pacific belonging to two sections. Section Fasciculata is
largely Malcsian, extending eastwards to Fiji, and sect. Leiospemium is largely
Pacific, occurring as far west as Papua New Guînea. The structure of the
inflorescence provides previously unrecognised characters of taxonomie
importance, cspecially al the sectional lcvel. Because of the high levcls of
local endemism, species accounts foi the whole région are divided into four
parts. Descriptions, illustrations and distribution maps are provided here for
KEYWORDS
Weinmannia, four species: W. Jraxinca, a widespread ochlospecies; W, ckmensiae, a local
Cunoniaceae, endemic on ultramafic substrates in Sabah; W. apbanoneura, from Bornéo
inflorescence structure,
and Sumatra, and W. hooglandii H.C. Hopkins & J.C. Bradford, sp. nov.,
Malesia,
Pacific, from Peninsular Malaysia.
RÉSUMÉ
La Malésie et le Pacifique renferment environ 40 espèces de Weinmannia
(genre essentiellement tropical et montagneux), réparties dans deux sections :
sect. Fasciculata, présente surtout en Malésie et répandue il l’est jusqu à Fiji ;
sect. Leiospermum, surtout Pacifique, s'étendant à l’ouest jusqu'à la
Papouasie-Nouvelle-Guinée. La structure des inflorescences fournit des
caractères d importance taxonomique, surtout pour la distinction des sec¬
tions, qui n'avaient pas été utilisés jusqu’à maintenant. En raison de l'impor¬
tance de l’endémisme local, l'étude des espèces répandues dans l’ensemble de
cette région est divisée en quatre parties. Des descriptions, illustrations et
MOTS CLÉS
Weinmannia, cartes de répartition sont fournies ici pour quatre espèces : W. Jraxinea une
Cunoniaceae, ochloespèce largement répandue ; W. clemensiae endémique de Sabah, sur
structure inflorescenriellc,
substrats ultrarnafiques ; W. apbanoneura, de Bornéo et Sumatra, et W. hoo¬
Malésie,
Pacifique. glandii H.C. Hopkins & J.C. Bradford, sp. nov., de la Péninsule malaise.
ADANSONIA, sér. 3 • 1998 • 20(1) 5
Hopkins H.C.F.
INTRODUCTION paper présents hackground information, an
account of the widespread and variable Wein-
Weimnannia is the largest and most widespread manma fraxinen (D. Don) Miq. and of the
genus in the predominantly woody, Southern remaining species in Western Malesia, rhe fesser
hemisphere family, Cunoniaceae, and it contains Sunda Islands and the Moluccas; part 2
almost half the 300 or so species of the family as (HOPKINS 1998a) deals' with the species of
it is currently circumscribed in BrummiïT Sulawesi and the Philippines; part 3 (HOPKINS
(1992). There are about 80 species in tropical 199Sb) describes the species thar occur in New
America (BERNARDI 1961, 1963a), ar least 30 in Guinea and the islands of rhe western Pacific;
Madagascar and rhe Mascarene Islands and part 4 (HOPKINS & FLORENCE 1998) deals
(Bernardi 1964, 1965; J.C. Bradford pers, with the islands of the central Pacific and pré¬
comm.) and ca. 4() in Malesia and rhe Pacific sents an index to taxa, including synonyms.
(BERNARDI 1964 and this révision). The présent Where appropriate, régional papers hâve been
day distribution of the genus is thus rather further divided by island group, each with a
curious since it is absent from Africa, mainland separate key. This arrangement bas been adopted
Asia excepr for Peninsular Malaysia, and from in part to reflect the high degree of régional and
Australia, which is part of the région of greatest island-group endemism, m part to reflect author-
generic diversiry for the family. However, fossil ship of rhe accounts, and in pan because the prob-
leaves with affinities to Weinmannia lems remaining in Samoa and rhe Cook Islands
(Weinmanniapkyllum) hâve been described from preclude a uniform treatmenr of ail taxa in a
Oligocène deposits in Tasmania (CARPENTF.R & single alphabetical list. l'hose wishing to see a
Buchanan 1993) suggesting thar it may once comprehensive key and alphabetical treatment of
hâve occurred in places where it is now extinct. species for Malesia will find this eventually in
Weimnannia is largely tropical and montane Flora Malesiana, In the meanfime, the scctional
though it occurs in subtropical and temperate keys of BERNARD! (1964) are helpful. with sonie
forest in South America and in New Zealand, and minor adjustments for new and recircumstribed
in lowland tropical forest in Madagascar. The taxa. An identification list of specimens seen
taxonomie history of the genus was discussed by (excluding New Zealand, Samoa and the Cook
Bernardi (1961). Islands) will bc deposited in major herbatia or
In the most recent treatment of the Malesian- available from P.
Pacific speçies, BERNARDI (1964) reçognised 40 Only one species, Weinmannia fraxinea, is
species in two sections but he rarely gave com¬ widespread in Malesia and the western Pacific,
plété descriptions except for new taxa. In add¬ occurring from northern Sumatra to the
ition, much new material has become available Solomon Islands. It is described in some detail in
since his work (e.g. 2/3 of the collections of W this paper. Where this and other species occur in
urdanetensis Elmer and W. pullei Schltr. from the more thao one région (e.g. W. urdanetensis in the
Highlands of New Guinea hâve been collected Philippines and New Guinea; W. txtgua A.C.
since 1959). R.D. HOOGIAND, who had a long- Sm. in the Solomon Islands and Fiji), the des¬
standing monographie interest in the family, cription and synonomy are given only once.
started to révisé Weimnannia fot Malesia and the My species concept is morphological (see
Pacific in the 1970s. The présent study has McDADI 1995) and aims ro be consistent with
drawn on his extensive collection of taxonomie the définition of CttONQUIST (1978) as the small-
literature, notes on morphology and typification, esr group that is consistently and persistently dis¬
and a catd index of specimens. However, the spe¬ tinct and distinguishable by oïdinary means. [t has
cies concepts and descriptions are mine unless been suggested that over reliante on leaf chatacters
otherwisc indicated. (especiaJIy size and number of leaflets) has lead to
My study was based largely on herbarium mat¬ taxonomie confusion and the over description of
erial with field observations in Malaysia, Fiji and species in Weinmannia. However, there are few
New Caledonia. It is divided into four parts: this other characters available, as features of the flowers
ADANSONIA. sér. 3 • 1998 • 20(1)
6
Weinmannia in western Malesia
and fruits are rarely taxonomicaJIy uscful at the ECOLOGY AND DISTRIBUTION
species level. Thus many taxa differ by combina¬
tions of quantitative characters, none of which is Weinmannia species are typically trees and
diagnostic on its own, The structure of the inflor¬ shrubs of humid, montane forests, often growing
escence has provided some new characters, part- where there is persistent cloud cover and quite
icularly at the sectional level, but it is rather high, well distributed rainfall. Twigs and leaf
uniform amongst the species in Malesia. blades are often covered with mosses and other
There has been a wealth of anatomical work on epiphytes. Within Malesia, the genus grows at
Cunoniaceae and its relatives (e.g. DlCKISON mid to high élévations (up to 2600-2800
1975a,b, 1977. 1980a,b, 1984; Govn & Saxena (-3000) m) in Bornéo, Sulawcsi and New
1976; Hideux & Ferguson 1976; Rao 8c Guinea) although a few species occur near sea
Dickison 1985; Rutishauser 8t Dickison level. In the Pacific, Weinmannia is absent from
1989) and many of the characters investigated low coralline îslands but widespread and some-
hâve proved uscful in understanding relation- times abundant on the high volcanic ones.
ships wïthin the family and with its close relat¬ Végétation zones hère are more compressed than
ives (Hufford 8c Dickison 1992). However, in Malesia, and Weinmannia is typically found at
species délimitation in Weinmannia is aggravated 300-750+ m, The genus also occurs on islands of
by lack of strong morphological divergence, and continental origin, from 150-1550 m in New
anatomical characters are unlikely to be useful at Caledonia, and from ca. 300-1180 m in New
this taxonomie level. Zealand (W racem-osa, fide Wardle 1966).
Within Cunoniaceae, Weinmannia is cjosely Weinmannia often occurs on ridges, steep
related to Cunonia (ENGLER 1930-, HUFFORD & slopes and in areas of disturbance due to tree
Dickison 1992), with which it is sympatric in falls, landslides or volcanic éruptions. It is some-
New Caledonia. It differs from Cunonia in the times an early coloniser on volcanic slopes and
form of the floral dise (which is adnate to the along roadsides (e.g. W. fraxinea in Sabah,
base of the ovary in Cunonia and composed of Weinmannia sp. in central Vin Levu) where it
either free lobes or a continuous ring, attached tolérâtes high light intensity. While it is found
only at its base, in Weinmannia), the dehiscence on a range of soil types, it often occurs on ones
of the fruit (dehiscing in a circle round the base with arypical minerai composition, including
and acropetally along rhe sutures, the valves soils derived from ulrramafic substrates and on
remaining attached to the central column at the the leached soils associated with disturbed sites
apex in Cunorua\ dehiscing septicidally or septi- in cloud fbrest. Frequent plant associâtes are the
fragally from the apex, and the valves and central fems Gleichenia and Dieranopteris which are typic-
column remaining attached at the base in al of burnt or repeatedly eut sites on impover-
Weinmannia) and in the seeds (angular and often ished soils, often rich in aluminium.
narrowly winged in Cunonia; ellipsoidal, comose A few species hâve very spécifie écologies (e.g.
at both ends or throughout and not winged in Weinmannia clemensiae Steenis from stunted
Weinmannia) HUFFORD 8c DlCKlSON’s analysis foresr on ultramafic soit) while others show
also suggests a close affinity with Pancheria but considérable ecological plasticity and are found
this genux differs markedly from the other two in over a broad altitudinal range (e.g. W fraxinea in
its capitate inflorescences. parts of Malesia and W parviflora G. Forst in
Weinmamiia has litrle économie importance in Tahiti), and both these species arc morphologic-
Malesia and the Pacific. The bark contains high ally vety variable. Weinmannia croftii H.C.
levels of tannins and some species arc used for Hopkins from the Bismarck Archipelago is
tanning and firewood but few local uses are found both as an early coloniser of volcanic
recorded. The Flowers of Weinmannia racemosa deposits and in adjacent closed, montane forest
L. f. are visited by bees which in turn produce (D. Frodin pers. comm.).
honey on a commercial scale in New Zealand Most species of Malesian-Pacific Weinmannia
(J.C. BRADFORD pers. comm.). hâve quite restricted distributions and there is a
ADANSONIA, sér. 3 - 1998 • 20(1) 7
Weinmannia in western Malesia
high degree of island or island-group endemism. posed an infrageneric classification of
Within Malesia, W. fraxinea is the only wide- Weinmannia with six sections. According to
spread specics. In contrast with parts of the BERNARDI, sections Weinmannia(e) and
Andes and Madagascar (J.C. BRADFORD pers. Simplicifolia(e) are principally American, with a
comm.), there are fcw sympatric or co-occurring few species in the Mascarene Islands (sect.
species of Weinmannia in any part of its Weinmannia); sections Spicala(e) and Inspersa(e)
Malesian-I’acific distribution It is of note that are confined to the western Indian Océan
there are only four species in New Caledonia, (Madagascar and Comores); and the Malesian-
which is a centre of species richness for the Pacific species are placcd in sections
Cunoniaceae, with a total of about 90 species. It Fasctculata(e) and Leiospermum (referred to as
seems likely that here, Weinmannia is at least sect. Raccmosae by Bernardi). The lacter also
partly replaced by Cunonia, which is morpholog- conrains two Malagasy species, W. comorcnsis 1 ul.
ically sîmilar in many respects. and W baehniana Bernardi, Sections Fasciculata
Weinmannia bas smal! seeds that are probably and Leiospermum are distinguished from the
wind-dispersed (see below). Anemochory, poss- others by the form of the floral dise, which is
ibly with the aid of cyclones, and the opportuniste composed of eight free lobes alternaung with rhe
ic ecological strategy of some species tie in well filaments, rather than a continuous ring
with dispersai to, and establishment on, groups (BERNARD! 1964: 132). In sect. Fasciculata, the
of remote volcanic islands within the Pacific. flowers are arranged in “pseudoracemes" whilst
Despite rhe rôle that the break up of in sect. Leiospermum they are dispersed. on pedi-
Gondwanaland may hâve played in the world¬ cels, in racemes or panicles (BERNARDI 1964:
wide distribution of the genus, more recent dis¬ 132).
persai events hâve dearly also had an impact. Prdiminary results of phylogenetîc studies in
Weinmannia is an important component of the progress, based on morphological characters,
végétation in some parts of its distribution, .such especially of the inflorescence, and on DNA
as the Society and Marquesas Islands, and New sequeneing (BRADFORD in press and pers.
Zealand. Those specics that, like W. Jraxinea, are comm ) support the monophyly of both sections
tolérant of natural disturbance, are likely to Leiospermum (morphology; DNA still unresolv-
become more abundant with increasing human ed) and Fasciculata (strong support from DNA
impact. However, some restricted endémies may sequences), although their relationships writh
he of conservation interest including W. clemens- other sections are still unclear. A few species were
iae from the Mt. Kinabalu massif in Sabah, W misplaced by BERNARD!; the Indian Océan spe¬
paitensis Schltr., which is confjned to a few cies he placée! in sect. Leiospermum belong with
mountains in cenrral and Southern New the Malagasy sect. Spicata, and W descombesiana
Caledonia and W. ouaiemensis (Guillaumin & Bernardi, placed by BERNARD! in sect.
Virot) Hoogland, Icnown from only a single local- Leiospermum, belongs with the Malesian sect.
ity in north-eastem New Caledonia. Some other Fasciculata (Bradford pers. comm.).
species are known from very few collections but Section Fasciculata is a cohesive group of spe¬
we hâve too little information at présent to assess cies. In addition to having the flowers inserted in
their conservation status. Several species such as fasdcles on the inflorescence axis (to form the
W. rapensis F. Br. and W raiateensis J.W. Moore, “pseudoracemes" of Bernardi), these species
are endentic to small Pacific islands, but they are share a coinmon, rather complex, inflorescence
not currently considered threatened. plan (see below). Weinmannia descombesiana is
somewhat problematical sitice it combines some
characters of both sections Fasciculata and
RELATIONSHIPS OF THE Leiospermum. Section Fasciculata is mo.stly
MALESIAN-PACIFIC SPECIES Malesian, extending as far as east as Fiji (Fig. I).
Section Leiospermum is confined to the Pacific,
Bernardi (1961, 1963a,b, 1964, 1965) pro- extending westwards as far as the Bismarck
ADANSONIA, sér, 3 (cid:9632) 1998 (cid:9632) 20(1) 9 I
Hopkins H.C.F.
Archipelago and Karkar Island in Papua New caducous as the leaves enlarge; in the later case,
Guinea (Fig. 1). Most Pacific species form a clos- they leave a distinctive annular scar. Similar
ely knit group (e.g. W. parviflora, W. purpurea structures cover developing (partial) inflores¬
L.M. Perry, W. vitiensis Seem.). Those from New cences and are also found at nodes within the
Caledonia form anocher group with minor différ¬ inflorescence in sect. Leiospermum where the
ences in the flowers, which are aJways bisexuaJ, leaves are wholly or partly suppressed. When
and the inflorescence structure. The New found in the inflorescence, the stipules are usual¬
Zealand species form a third group. Their flow¬ ly more oblong-elliptic than at végétative nodes.
ers are inserted singly but hâve a greater tendancy Stipules can be variable in size and shape on a
ro be perigynous and the structure of the inflor¬ single specimen and they are of varying value as
escence shows some différences from the remain- taxonomie characters. They are offen absent from
ing Pacific species. The species of rhe Marquesas the fertile shoots of some species and tend to be
Islands, at th extreme east of Weiv-manmas dis¬ larger and more persistent on végétative shoots.
tribution in the Pacific, hâve their afflnities with The arrangement of leaves is always opposite
the other Pacific species, not the American ones, and decussate, giving a distinctive appearance
(Fig. 2A). Compound leaves are usually impari-
pinnate though the terminal leaflet is sometimes
NOTES ON MORPHOLOGY AND absent or fused to a latéral one. The petiole and
BIOLOGY leaf rachis can be winged or not, and sometimes
the distinction berween these two States is not
1. Végétative axes marked. In Malesian and Pacific species, the
Branching in most species of Weinmannia is wings are never as well developed as in some
from axillary buds, accompanied by the contin- American ones. The size and shape of the leaves
ued growth of the apical bud, and the architect¬ and leaflets, and the amount and distribution of
ure cooforms to Rauh’s rnodel (KELLER 1996), indumentum, are often taxonomically signifi-
However, in several species of sect. Leiospermum cant. l.eaflet size i.s small to medium, and in
the apical bud of growing shoots can be aborted contrast to the Neotropics, no species is micro-
and branching is then dichotomous. Most of phyllous. The rnargin is almost always distinctly
these species show a mixture of branching patt¬ dentate or crenate, and in W. serrata Brongn. &
erns, but in Weinmannia dicbotoma Brongn. & Gris, some-what sinuate. In young leaflets the
Gris, branching is almost exclusively dichotq- ends of the teeth are pronounced and probably
mous. Occasionally four buds at a node will glandular.
develop, producing four stems of equal domin¬ The venation is rather uniform. Secondary
ance (e.g. W dicbotoma, W dffinis A. Gray). The veins usually start to branch and anastomose
buds that develop in this instance are latéral to
the axillary buds, and in a plane perpendicular to
the line: leaf- axil - (apical bud) - axil - leaf, and Fio. 2.—A. Weinmannia fratioea, ’oliage ot immature shoot,
are referred to as latéral, auxiliary buds; again, showing opposite and decussate oompound leaves and large,
rounded, salvertorm Interpeliolar stipules at nodes; young folia-
the apical bud is aborted. ge reddish. (Hopkins et al 5001a. Ml. Maiang. Sarawak) —B,
In Weinmannia, as in most other Cunoniaceae, Weinmannia clemensiae. loliage and immature fruits.
Intructescence a pair ot dyads with short padundes. Note large,
there is a pair of small, flattish, usually rounded
rounded stipules, (Hopkins A Bradiord 50W. Pig Hill, Kinabalu,
to ovate, leaf-likc structures betwcen the pétioles Sabah.l.—C, D, Weinmannia fraxmea "dulitensîsC, racemes
at each node, usually reftrred to as interpetiolar ot male flowers; D, base ot inflorescence showing 4 dyads sub-
tended by a pair of opposite petiotes, Noie ffowers inserted in
stipules (Rl'TLSHAUSER &t DlCKISON 1989; Fig. fascicles. (Hopkins & Bradiord 5014, Pig Hill. Kinabalu,
2A,B; 3Q). MELVILLE (1972) described them as Sabah).—E, Weinmannia richii, fruits at dehiscence.
Infructescenoes of dyads with very short pedundes. ( Hopkins S
bud scales and considered that they were not true Bradiord 5028. road N from Monosavu Dam. Viti levu. Fiji).—F,
stipules but that each was équivalent to an entire Weinmannia serrata, immature fruits. Infrudescence a central
pentad and one latéral trlad, with one raceme missing.
leaf. At végétative shoot apices, they cover the
(Bradiord 632, Col d'Amieu, New Caledonia).—Ail photos by
developing buds and can be either persistent or J.C. Bradford.
ADANSONIA. sér. 3 - 1998 • 20(1)
10
Weinmannia in western Malesia
ADANSONIA, sér. 3 • 1993 * 20(1) il
Weinmannia in western Malesia
before reaching margin but at least part of the intemodes, vestiturc, shape ot rachis, shape and
vein terminâtes at the tip of a tooth. Tertiary and persistence of stipules. Both W. richii and W.
quaternary venation are strongly reticulate. affims occur in this area but the stérile collections
Leaf/let texture is often coriaceous or at least were rarely consistent with the adule foliage of
chartaceous-coriaceous. Species that grovv at high either of them, Sonie of this variation could per-
altitudes usually have more numerous, smaller, haps bc- due to hybridization and the coloniz-
more coriaceous leaflets than those from lower ation of disturbed roadsides by hybrid swarms.
élévations. Black dots, which are probably the Characters of mature foliage are best seen in
bases of caducous hairs, are frequent on the leaves at the periphery of the crown m mature
underside of the leaves in sonie species. Such individuals (i.e. foliage from just below the
leaves are referred to as “puncrate" iti the species inflorescences).
descriptions. Pustules are small, pale protubér¬
ances on both the upper and lower surfaces of
leaflets and they can .tlso occur on other organ.s, 2. Structure of the inflorescence
such as the calyx lobes. They do not appear to {with J.C. Bradford)
have any taxonomie signifîcance nor to be an The parts of the inflorescence are organised hier-
artefact of drying (cf, BERNARD! 1964: 162). archically, and in Weinmannia, there are rypically
Juvénile faîtage and stérile collections. three levels of organisation; 1) flowers, borne
The characters that are diagnostic of adult foli- along an unbranched axis, here termed a raceme;
age are rarely évident in juvénile and coppice 2) racemes, organised into metameric units, each
shoots. For instance, a sériés of roadside collec¬ referred to here as a partial inflorescence (PI); 3)
tions from stérile individuals 1-3 m high near parmi inflorescences, borne along the main
Monasavu Dam, central Viti Levu, Fiji (Hopkins stem Togerher, the structure of a raceme, the
ér Bradford 5027a-h) show a range in variation in way the racemes are organised into a PI, and the
the number, size and shape of leaflets, length of arrangement of the Pis along the main stem,
constirute the inflorescence. Although there is
sorne interaction amongst levels of organisation,
with higher levels influencing lower ones, most
Fig. 3.—Details of the nodes, buds, flowers and fruits of variation within one level of organisation appears
Weinmannia A. flower; B. Hower with calyx and corolla remo-
to be independent of variation at another level.
ved to reveal dise lobes, filaments and gynoecium; C, l.s.
through B to show ovules, D, gynoecium with syncarpous ovary For this reason, each level of organisation will be
and 2 dise lobes: note groove down style and down side of
discussed separately
ovary: E, calyx lobe with ciliolate margin and 3 glands; F, pelai;
G, anthers, L.H.S, before dahlsoence, R.H S after dehlscence: There are several terms that require short défin¬
H, seed wilh hair tuH at each end and sculptured surlace, note itions so that the descriptions of the inflores¬
raphe down midline: J, t.s. ovary (D) to show developing ovules;
K, ouler surface ot one valve of a capsula showlng exocarp cences and their component parts can be made
(central pan sirigose) and endocarp exiended as wmgs al both clearly and coneisely. A bract is a minute, often
sides, on réceptacle, the calyx. lobes fallen but dise lobes persis¬
carinatc blade along the axis of a raceme and it
tent L, inner surlace ot K. note persistent centrai cotumn and
minutely sculptured shiny endocarp; M developing Inflores¬ subtends a flower or a group of flowers. A bud is
cence, one latéral Iriad shown in axii of petiole. note stipular
an undeveloped shoot or flower, which in
scar between pétioles, "collars" arourid latéral peduncles and
conical dilate buds at base ot latéral peduncles (latéral auxiliary Weinmannia is normally cnclosed by a bract (flow¬
buds): at base of triad there is a stipule (partly lolded baoK) and ers) or a pair of stipules (shoots). A stipule is a
a pair ot muen redueed leaves: N, section of axis of a raceme
typical ot secî. Leiospermum, thé pedicels inserred singly ig the small leal-like structure at a node, decussate with
axils of th6 bracts: P. section ot axis ol a raceme in sect. the crue leaves that may themselves be partially
Fasciculata, the pedicels inserted in tascides In the axils of the
bracts; Q. stipules between leaf petiotes ai most distal riode of ot wholly suppressed at nodes within die inflor¬
shoot protecting apical bud Scale bars i mm unless otherwise escence. A metamer is a unir which consists of an
indicated. |A-F, J, W. patlettëis (McPherson 3403); G, W. serra-
ta (Bernardi 12816); H, W. serrais (Balansa 204), K, l, W pait- internode, the node at its distal end, and the
ensis (Veiilon 296); M, W. serrata (Bnnon 746); N, W, serrata organs and meristems (buds) associated with that
(Balansa 2859); P, W. frarinea "dulitensf (Hopkins & Bradions
node. The term “main stem” is used for any
5014); Q, W. serrata (Lécard s.n., reçu 20 Oct. 1879)].—Drawn
by H.C.F. Hopkins. dominant, linear axis of growth.
ADANSONIA, sér. 3 • 1998 • 20(1) 13
Hopkins H.C.F.
a) Racemes.—The flowers of the Malesian- végétative growth after flowering. LJsually it is
Pacifîc species are pedicellate and borne in dormant during flowering (prolcptic) or rarely
racemes ca. 5-12 cm long. The bracts usually fall sylleptic (i.e. no cessation of growth).
when the flowers are still at the bud stage but — Sect. Leiopsermum A partial inflorescence
occasionally they persisr until fruiring. Afrer they can consist of more than one metamer. Usually,
hâve fallen, a minute scar is usually visible. The an odd number of racemes ate inserted at one or
individual flowers or Fascicles are rather irregular- more nodes along the axis of the PI as the termin¬
ly arranged on the axis of each raceme and insert¬ al meri.stem develops into a raceme. Theretore,
ion is never truly verticillate though it may when the PI consists of one metamer, there are 3
superficially appear to bc. Racemes may bear racemes (callcd a tri ad, Fig. 4F), when of two
flowers for the wbole of their length or usually metamers, there are 5 racemes (a pentad, Fig.
they are devoid of flowers towards the base. The 4G), and when of three metamers, there are 7
flowers in orie raceme open more or less simultan- racemes (a beptad). In a few species the Pis are
eously. dyad.s (Fig. 4H) and the bud between the bases
— Sect. Fasciculata, Several pedicels are insert- of the racemes has aborted (i.e, fai lcd to develop
ed in a small cluster in the axil of a bract (Fig. into a third raceme; exceptions in New Zeatand
3P). Occasionally flowers are inserted in fascicles are deseribed below). The basal intemode of a PI
for the most part but wirh some inserted singly may be loosely termed the peduncle.
towards the apex of the raceme, and in a few .spe¬ Leaf production can be either partially or total¬
cies, the fascicles rend to dissociate from the ly suppressed within each PI and when leaves are
bracts during development. BtRNARDl (1964: produced, they are much reduced (e.g. Fig. 4J,
132) used the term ‘pseudoraceme in reference level Y). There are often stipules at nodes within
to sect. Fasciculata, but since this term is rather a PL Quire often there are “collars” around the
ambiguous, it is not used hcre. base of the pcduncles of latéral Pis (Fig. 3M).
— Sect. Leiospermum. The pedicels of the flowers Thèse appear to be the rem riants ot a pair of stip¬
are inserted singly in the axil of a bract (Fig. 3N). ules which once covered the developing PI and
b) Partial inflorescences.—In general, a PI is were fused to each other at the base. They are
any subunit(s) into which the inflorescence can not usually seen around the peduncle of the
be divided. As used here, it consists of racemes central PI in sect. Leiospermum, nor around the
and one or more stérile stem sections which torm pedundes in sect. Fasciculata.
a developmentally integrated unit whose structure c) Inflorescences.—An inflorescence is compos-
is predictable wichin different taxonomie groups. ed ol one or more partial inflorescences. Usually
However, sometimes (though rarely in this ail the flowers in one inflorescence open more or
région) the inflorescence of Weinmannia is com- less simulraneously.
posed of individual racemes inserted in leaf axils, — Sect. Fasciculata (Fig 4A-E). The Pis devel¬
in which case the racemes could be considered to op in opposite pairs from latéral meristems at a
be the Pis. node on the main stem, ce. they are usually in
— Sect. Fasciculata. A partial inflorescence is the axils of leaves. Each PI is a dyad or a tetrad.
limited to a single metamer. An even number of The most distal végétative node on a stem usual¬
racemes (2 or 4) are inserted at lhe distal node of ly produces more pairs of Pis than do subdistal
a short, stérile stem segment (referred to as a nodes (see discussion of supernumerary buds
peduncle in the species descriptions) to form below) and often the initiation of Pis is confined
either a dyad (Fig. 4A) or a tetrad (Fig. 4B). Leaf to the most distal node on the main stem.
production is usually totally supptessed at the Since the Pis are latéral, the apical meristem of
node from which the racemes arise (exceptions the main stetn remains indeterminate, It is
seen in W. pullet) normally dormant during flowering and contin¬
There is typically a small bud in the angle bet- ues végétative growth after fruiting (prolepsis) or
ween the central pair of racemes at the apex of the rarely it may be sylleptic. In exccptional cases,
peduncle. This bud has the potential to continue the apical meristem gives rise to a media! PI but
sér.
14 ADANSONIA. 3 • 1998 • 20(1)
