Towards A Revision Of The Genus Vitex L. (Lamiaceae) In Madagascar I: A Distinctive New Species From Northeastern Madagascar

Abstract

Callmander, M. W., P. B. Phillipson & G. E. Schatz (2014). Towards a revision of the genus Vitex L. (Lamiaceae) in Madagascar I : a distinctive new species from North-eastern Madagascar. Candollea 69: 141–147. In English, English and French abstracts. A review of the genus Vitex L. (Lamiaceae) in the context of the “Catalogue of the Vascular Plants of Madagascar” project has led us to discover a number of probable new species and uncover other necessary taxonomic changes for the genus. One particularly distinctive new species, Vitex lowryi Callm., Phillipson & G. E. Schatz, is described and illustrated in this article, the first of a series in which we envisage presenting the results of our ongoing investigations on Malagasy Vitex. A discussion of the differences between the new species and a group of the morphologically most similar species of the genus in Madagascar is provided, together with photographs showing the key features of each. Finally, a distribution map and a preliminary conservation assessment following IUCN Red List Categories and Criteria are provided for the new species.

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© CONSERVATOIRE ET JARDIN BOTANIQUES DE GENÈVE 2014
ISSN: 0373-2967 – Online ISSN: 2235-3658 – Candollea 69(2) : 141-147 (2014)
Addresses of the authors: MWC: Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299, U.S.A. and Conservatoire et Jardin botaniques de la Ville de Genève,
case postale 60, 1292 Chambésy, Switzerland. E-mail: martin.callmander@mobot.org
PBP: Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299, U.S.A. and Département Systématique et Evolution (UMR 7205), Muséum national d’Histoire
naturelle, case postale 39, rue Cuvier 57, 75231 Paris, cedex 05, France.
GES: Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299, U.S.A.
Submitted on July 10, 2014. Accepted on August 25, 2014. Edited by P. Perret
Abstract
CALLMANDER, M. W., P. B. PHILLIPSON & G. E. SCHATZ (2014).
Towards a revision of the genus Vitex L. (Lamiaceae) in Madagascar I: a dis-
tinctive new species from North-eastern Madagascar. Candollea 69: 141-147.
In English, English and French abstracts.
A review of the genus Vitex L. (Lamiaceae) in the context of
the “Catalogue of the Vascular Plants of Madagascar” project
has led us to discover a number of probable new species and
uncover other necessary taxonomic changes for the genus. One
particularly distinctive new species, Vitex lowryi Callm.,
Phillipson & G. E. Schatz, is described and illustrated in this
article, the first of a series in which we envisage presenting
the results of our ongoing investigations on Malagasy Vitex.
A discussion of the differences between the new species and
a group of the morphologically most similar species of the
genus in Madagascar is provided, together with photographs
showing the key features of each. Finally, a distribution map
and a preliminary conservation assessment following IUCN
Red List Categories and Criteria are provided for the new
species.
Key-words
LAMIACEAE – Vitex – Taxonomy – Madagascar – IUCN Red
List
Résumé
CALLMANDER, M. W., P. B. PHILLIPSON & G. E. SCHATZ (2014). Vers
une révision du genre Vitex L. (Lamiaceae) à Madagascar I: une nouvelle
espèce caractéristique du Nord-Est de Madagascar. Candollea 69: 141-147.
En anglais, résumés anglais et français.
Une étude du genre Vitex L. (Lamiaceae) dans le cadre du
projet «Catalogue des plantes vasculaires de Madagascar»
nous a permis de découvrir un certain nombre de probables
nouvelles espèces et de changements taxonomiques pour ce
genre. Une nouvelle espèce particulièrement distinctive, Vitex
lowryi Callm., Phillipson & G. E. Schatz, est décrite et illus-
trée dans cet article, le premier d’une série dans laquelle nous
envisageons de présenter les résultats de nos investigations en
cours. Une discussion sur les différences entre la nouvelle
espèce et un groupe d’espèces du genre morphologiquement
similaires à Madagascar est présentée, ainsi que des photo-
graphies montrant les principales caractéristiques de chacunes.
Enfin, une carte de distribution et une évaluation préliminaire
de conservation suivant les Catégories et Critères de la Liste
Rouge de l’UICN est présentée pour la nouvelle espèce.
Towards a revision of the genus Vitex L. (Lamiaceae)
in Madagascar I: a distinctive new species from North-
eastern Madagascar
Martin W. Callmander, Peter B. Phillipson & George E. Schatz

142 – The genus Vitex (Lamiaceae) in Madagascar I Candollea 69, 2014
Introduction
The genus Vitex L. (Lamiaceae) comprises c. 250 species,
and is distinguished within subfamily Viticoideae by its palmate
leaves (occasionally unifoliolate), its terminal or axillary
inflorescence, (4-)5(-6) corolla lobes and a 1-4-seeded fruit
(BRAMLEY & al., 2009). This pan-tropical genus, which also
has a few species in temperate regions, has its primary centre
of diversity in South East Asia – a region for which excellent
recent taxonomic revisions are available for the genus (DEKOK,
2007, 2008). Madagascar is also an important secondary cen-
tre of diversity for the genus and was revised by MOLDENKE
in 1956 for the Verbenaceae volume of the “Flore de Mada-
gascar et des Comores”, which followed his earlier descrip-
tions of eighteen new species in the series of articles “New and
noteworthy plants” in the journal “Phytologia” (MOLDENKE,
1951, 1953). In the Flora treatment Moldenke accepted 39
species native to Madagascar, to which all but two of the native
species are endemic, distributed in a broad diversity of habi-
tats across the entire island. Moldenke also noted the presence
of certain introduced species, at least one of which has become
naturalised. Subsequently only two additional species have
been described from Madagascar: V. menabeensis CAPURON
(1972: 51) and V. masoalensis SCHATZ (1990: 207).
In the course of reviewing the genus Vitex for the “Cata-
logue of the Vascular plants of Madagascar” (MADAGASCAR
CATALOGUE, 2014), MWC and PBP reviewed all of the avail-
able specimens in the herbaria at G, MO and P. Only about 190
collections of the genus Vitex in Madagascar were available to
MOLDENKE in 1956, whereas today we estimate that a total of
at least 1400 have been made (based on data in TROPICOS, 2014
and SONNERAT, 2014), representing a 7-fold increase in the
specimen-base. Furthermore, it is remarkable that approxi-
mately half of the known collections (about 700) have been
made in the past 24 years since V. masoalensis was described
by GES in 1990. This vast amount of additional material per-
mits a much better understanding of the diversity and distri-
bution of the genus in Madagascar than was previously possi-
ble and our review for the Madagascar Catalogue has revealed
at least 14 new species awaiting description, as well as other
necessary taxonomic and nomenclatural changes. Elsewhere
we have already published the new combination V. hispidis-
sima (Seem.) Callm. & Phillipson based on material that was
originally mistakenly referred to the genus Colea Meisn.
(Bignoniaceae), thus providing the correct name for the species
referred to previously as Vitex congesta Oliv. (PHILLIPSON &
CALLMANDER, 2013).
In this first in a series of planned articles focusing on the
Malagasy Vitex, we describe a distinctive new species from
northeastern Madagascar, and provide a discussion of its mor-
phological affinities and a risk of extinction assessment fol-
lowing the IUCN Red List Categories and Criteria (IUCN,
2012). Calculations of the “Area of Occupancy” (AOO),
“Extent of Occurrence” (EOO) and number of subpopulations
were based on the methods presented in CALLMANDER & al.
(2007).
Taxonomy
Vitex lowryi Callm., Phillipson & G. E. Schatz, spec. nova
(Fig. 1, 2A).
Typus:MADAGASCAR. Prov. Antsiranana : Tsihoma -
naomby massif, ca. 23 air-km NW of Sambava, W of
Ambavala (PK 269 on Sambava-Vohémar road, RN 5a),
14°06’08’’S 50°02’46’’E, 150 m, 7.V.2000, Lowry & al.
5178 (holo-: MO-798818!; iso-: P [P04396770]!, TAN!).
Haec species a congeneris madagascariensibus foliolis
abaxialiter secus venas necnon petiolis petiolulisque indu-
mento ferrugineo-aurantiaco villoso longo persistente
copioso vestitis atque indumento longo densissimo pallide
aureo inflorescentiam floremque tegente bracteolas bre-
vissimas sicut lobos calycinos occultante distinguitur.
Monocaulous treelet 4-15 m tall. Leaves palmately com-
pound, 3-5-foliolate, with a generally persistent, long, villous,
rusty-orange indument; leaflets obovate to elliptic, sub-sessile
to shortly petiolulate, chartaceous, the largest (median) leaflets
20-35  8-15 cm, the blades undulate, dark green above and
olive green below in vivo; base attenuate; apex rounded; mar-
gin entire; abaxial surface covered by a dense rusty-orange
indument on the veins, with similar but shorter and more sparse
indument between the veins; adaxial surface sometimes with
sparse and apparently caducous rusty-orange indument on the
midrib and main veins, rugose between the veins; midrib and
main veins prominent below and somewhat impressed above;
petiole stout and stiff, 7-11 cm long. Inflorescence a much-
branched but highly condensed cyme, borne on the trunk
and in the axils of leaves, completely covered by a very dense
silvery to golden sericeous indument; cyme-branches up to
2-3 cm long, c. 2 mm in diam. Flower c. 3 cm long, sub-ses-
sile, subtended by a very short bracteole obscured by the dense
indument. Calyx cupuliform, the lobes reduce to a minute
apical tooth, c. 6-8 × 8-10 mm, 5-lobed, sericeous. Corolla
zygomorphic, broadly funnel-shaped, c. 25 mm long, 25 mm
wide and 30 mm high, 5-lobed; throat c. 5 mm diam. at the
base, c. 15 mm diam. at the mouth; inner surface glabrous,
pale yellow sometimes lightly tinged dull pink towards the
margin; outer surface densely pubescent, pale yellow or dull
pink; upper pair of lobes fused, 10 10 mm, free for the
distal 1/3, the free portions triangular, apices broadly acute;
lateral lobes 10 6 mm, triangular, apices shortly rounded;
lower lobe 10 5 mm, lingulate, with a rounded apex. Sta-
mens 4, curved and appressed to the upper lobes; filaments
c. 22 mm long, the proximal 7 mm villous, exserted c. 6 mm,
pale yellow, the exserted portion sometimes tinged dull pink;

Candollea 69, 2014 The genus Vitex (Lamiaceae) in Madagascar I – 143
Fig. 1. – Vitex lowryi Callm., Phillipson & G. E. Schatz. A. Leaf, with detail of indument on abaxial surface inset; B. Inflorescence; C. Flower (front view); D. Flower (three-quarter view).
[Lowry & al. 5178, TAN, P, photos] [Drawing: R. L. Andriamiarisoa]
A
B
C
D
2 mm
10 mm
2 cm
4 cm

144 – The genus Vitex (Lamiaceae) in Madagascar I Candollea 69, 2014
anthers compressed ovoid, c. 2 1 mm long, purple with pale
yellow pollen. Style curved and appressed to the upper lobes,
25-35 mm long, bifid for the distal 3 mm. Fruit unknown.
Observations. – Vitex lowryi falls in a group with four other
species in Moldenke’s identification key (MOLDENKE 1956 :
76, couplet 45), characterized by having large 3-7-foliolate
palmately compound leaves, with the leaflet length to width
ratio of 2-4 :1; flowers with tubular (vs. bilabiate) corollas,
borne on compact dense, mostly cauliflorous inflorescences.
A new identification key to this group of Vitex and other related
species will be provided in a forthcoming publication as
several other species still need to be recognized. Among these,
V. lowryi is easily distinguished in flower from V. hispidissima
(= V. congesta) and V. coursii Moldenke (= V. pulchra Mold-
enke) by its short broadly funnel-shaped (vs. long curved cylin-
dric) corolla, and from V. waterlotii Danguy, by the curved
stamens and style appressed to the upper lip of the corolla and
slightly exserted (vs. the stamens and style straight, patent, and
well exserted). It is most similar to Vitex hirsutissima Baker
which has a similarly shaped corolla, stamens and style, but it
differs by the extremely dense, long, pale golden indument on
the inflorescence and outer parts of the flower which obscures
the very short bracteoles and calyx lobes (vs. less dense,
shorter, red-brown indument, with the longer bracteoles and
calyx lobes clearly visible). Vitex lowryi also differs from Vitex
hirsutissima by its copious, persistent, long, villous, rusty-
orange indument on the veins of the abaxial surface of the
leaflets, the petioles, and the petiolules (vs. caducous, short,
sparse, appressed, red-brown indument on the veins of the
abaxial surface of the leaflets, and short, very sparse, appressed,
pale grey indument on the petioles, and the petiolules). Vitex
masoalensis also belongs to this group of closely related
species, but is easily distinguished from V. lowryi (and V. hir-
sutissima), with which it shares the short, funnel-shaped corolla
and curved stamens and style appressed to the upper lip of the
corolla, by its massive, sessile leaves. A set of representative
photographs for these six species is given in Figure 2.
Distribution and ecology. – Vitex lowryi is endemic to
north-eastern Madagascar. It is known only from three collec-
tions in remnant patches of low elevation (c. 100-300 m) for-
est between Sambava and Vohemar: on the Tsihomanahomby
Massif, Analalava forest near Antsatoby and a forest patch just
south of Antsirabe Nord (Fig. 3). The new species is not sym-
patric with any of the morphological similar species: V. water-
lotii is confined to dry forest on limestone in the far north;
V. hirsutissima, V. hispidissima and V.masoalensis occur on
the Masoala Peninsula and around the Baie d’Antongil area,
while V. coursii occurs further south in escarpment forest at
mid-elevation near Moramanga and Lac Alaotra.
Etymology. – This plant is named in honor of our friend
and colleague Porter P. Lowry II who collected the type speci-
men. Pete first visited Madagascar in 1986 during the early
days of Missouri Botanical Garden’s Madagascar Programme,
in which he has played a key role ever since. He has collected
more than 2,000 collections in Madagascar and is also respon-
sible for many excellent plant photographs, including several
different species of Vitex. His specimens, field description and
photographs of the species described here provided us with
important information.
Conservation status. – With an EOO of 207 km², an AOO
of 27 km² and three subpopulations, none situated within the
protected area network, Vitex lowryi is assigned a preliminary
status of “Endangered” [EN B1ab(i,iii,iv,v)+2ab(i,iii,iv,v)] fol-
lowing IUCN Red List Categories and Criteria (IUCN, 2012).
The new species is known from only three locations in isolated
evergreen lowland forest remnants. The available habitat of
the species is severely threatened, and is expected to diminish
significantly in the future, in which case V. lowryi may become
“Critically Endangered”.
Paratypi. – MADAGASCAR. Prov. Antsiranana: env. S Antsirabe-
Nord, sur la nouvelle route Vohémar-Sambava, [14°00’11”S
49°57’47”E], 18-21.X.1966, Service Forestier 24890 (G, MO, P
[P04396771], TEF); Vohémar, Vohimarina, Fanambana, Antsatoby,
forêt de transition d’Analalava, 13°37’32”S 49°59’42”E, 1.VII.2007,
Rasoafaranaivo 173 (MO, P [P00853158], TAN).
Acknowledgments
The authors thank the Parc Botanique et Zoologique de
Tsimbazaza and the Missouri Botanical staff in Antananarivo
for help and support in this study. We thank Roger Lala Andri-
a miarisoa for his fine illustrations, Rogier de Kok for review-
ing an earlier version of this manuscript, and Pete Lowry,
Richard Randrianaivo and Patrice Antilahimena for permis-
sion to use their photographs. We are also grateful to the cura-
tors of the following herbaria for access to their collections:
G, MO, P, TAN and TEF. Financial support was by grants from
the Andrew W. Mellon Foundation.

Candollea 69, 2014 The genus Vitex (Lamiaceae) in Madagascar I – 145
Fig. 2. – Inflorescences of Vitex L. species from Madagascar. A. Vitex lowryi Callm., Phillipson & G. E. Schatz; B. Vitex coursii Moldenke; C. Vitex masoalensis G. E. Schatz ;
D. Vitex waterlotii Danguy; E. Vitex hirsutissima Baker; F. Vitex hispidissima (Seem.) Callm. & Phillipson.
[A: Lowry & al. 5178;B : Antilahimena 8437; C: Schatz 1353; D : Randrianaivo 1099; E : Lowry 4481;F : Lowry 4340] [Photos: A, E-F : P. P. Lowry II; B : P. Antilahimena;
C: G. E. Schatz; D: R. Randrianaivo].

146 – The genus Vitex (Lamiaceae) in Madagascar I Candollea 69, 2014
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HARPER & al. (2007).

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