National Agriculture and Forestry Research Institute, Laos
Faculty of Science, National University of Laos
Science, National University of Laos
20A Inverleith Row
Edinburgh EH3 5LR
Reproduction of any part of this publication for educational, conservation and
other non-profit purposes is authorised without prior permission from the
copyright holder, provided that the source is fully acknowledged.
First published 2007
Front cover: Murdannia macrocarpa D.Y.Hong, Newman et al. LAO 706. Photo,
P.I. Thomas, Royal Botanic Garden Edinburgh
Back cover: Forest on limestone karst, Mahaxay District, Khammouan. Photo, P.I.
Thomas, Royal Botanic Garden Edinburgh
Acknowledgements _______________________________________________ vi
Introduction ____________________________________________________ 1
Introduction in Lao _____________________________________________ 17
The Checklist __________________________________________________ 25
1. Spore-bearing Plants _________________________________________ 25
2. Gymnosperms ______________________________________________ 34
3. Angiosperms _______________________________________________ 38
Introduced, Cultivated and Naturalized Species _______________________ 367
Index to the Plant Genera of Lao PDR _______________________________ 375
This project is funded by grant 13007 from the Darwin Initiative to the Royal Botanic
Garden Edinburgh and its three Laotian partners, namely the Forestry Research Centre,
part of the National Agriculture and Forestry Research Institute, the Department of
Biology, Faculty of Science at the National University of Laos and IUCN Lao PDR.
We are particularly indebted to the Watershed Management and Protection Authority
of Nakai Nam Theun National Protected Area which gave permission to our project to
train botanists and collect plants within their area.
We thank the Director of the National Agriculture and Forestry Research Institute
and the Dean of the Faculty of Science, National University of Laos who have welcomed
this project and ensured that it had all the necessary permits to run smoothly. In Lao PDR
we should also like to thank Mr Banxa Thammavong, Mr Singkone Saynhalat and Ms
Phayvone Phonphanom from the Forest Research Center, Mr Soulivanh Lanorsavanh
and Ms Phetlasy Souladet from the National University of Lao PDR for their enthusiastic
support during the project. Mike Callaghan, ECOLAO generously allowed us to use an
electronic version of his publication ‘Checklist of Lao Plant Names.’ Joost Foppes and
Martin Greijmans from Stichting Nederlandse Vrijwilligers (SNV) and Pierre Bonnet
and Pierre Grard from the Orchisasia and BIOTIK projects also provided knowledge,
advice and support.
Thanks are due to Andrew Ingles and the Bangkok office of IUCN for their support of
our collaboration with IUCN Lao PDR. We gratefully acknowledge the support, advice
and hospitality of Dr Kongkanda Chayamarit and Dr Rachun Pooma at the Bangkok
We also acknowledge the help of many experts on plant groups who have named
plants for us and contributed information. Among the many people who have
contributed their time and knowledge are Paul Keßler, Colin Ridsdale, Frits Adema,
Cornelius Berg, André Schuiteman, Luc Willemse, Willem de Wilde & Brigitte de Wilde-
Duyfjes from Leiden, Sovanmoly Hul from Paris, Christian Puff from Vienna, Robert
Faden from the Smithsonian Institute, David Middleton, Martin Pullan, Colin Pendry,
Robert Mill, David Chamberlain, Christopher Fraser-Jenkins from RBG Edinburgh and
Dave Simpson, Mark Coode and Rafael Govaerts from RBG Kew. We should also like
to thank the herbarium staff at RBG Edinburgh for their support and help along with
the curators of the herbaria at Leiden and Paris for facilitating access to their collections
The flora of Lao PDR is one of the least known in Asia, though it was revised in
the Flore générale de l’Indochine (Lecomte 907–950) and is being revised again in
the Flore du Cambodge, du Laos et du Viêtnam (Aubréville 960–present). The reason
this flora is so poorly known is that very few people have spent time studying and
collecting in Lao PDR with the result that there are very few herbarium specimens
Both the flora-writing projects just mentioned have treated Lao PDR together
with its neighbours, Cambodia and Vietnam and the great majority of specimens
cited in them are from Vietnam where botanical collecting has always been
more intensive than in Lao PDR or Cambodia. Nowadays, responsibility for the
conservation and management of biodiversity rests with national governments,
however, so there is a great need for an overview of the plants of Lao PDR, separate
from those of Cambodia and Vietnam. At its simplest, a list of the names of plants
occurring in Lao PDR would be extremely valuable.
Prior to this publication, two checklists for the plants of Lao PDR have been
published. The first, Noms vernaculaires de Plantes en Usage au Laos (Vidal 959),
listed more than 000 species with their local names and uses. The second, the
Checklist of Lao Plant Names (Callaghan 2004) lists more than 2000 taxa, including
more than 300 cultivated and introduced plants. This second checklist is primarily
based on Vidal’s work, the fascicles of the Flore du Cambodge, du Laos et du Viêtnam
that have been published since 960 and a range of unpublished field surveys. These
checklists focus on useful plants and therefore only represent a limited section of
the flora. The need to conserve and manage the flora at national level is now greater
than ever so it is even more important to develop a National Checklist.
History of plant collecting
The first botanical collectors in Lao PDR were all French. Clovis Thorel was the first
to make a significant contribution, collecting along the Mekong in southern and central
Lao PDR from 866–868. He was followed by Jules Harmand who also worked mainly
in the south in the 870s. These pioneers were followed by Henri D’Orléans (892,
in northern Lao PDR), Clément Dupuy (900, around Louangphrabang) and Jean-
Baptiste Counillon (909, along the Mekong). The most prolific collector in the 20th
century was Eugène Poilane who worked in various provinces of Lao PDR from the
920s–940s. At the same time Camille Joseph Spire was collecting in Xiengkhouang.
More detail about the flora and collectors in Cambodia, Lao PDR and Vietnam may be
found in the “tome préliminaire” to the Flore générale de l’Indochine (Gagnepain 944).
Historical events all but prevented botanical work in Lao PDR between World
War II and the 990s though some collections were made by Jules Vidal, Pierre Tixier
and Allen D. Kerr in the 950s and early 960s. Taking all these Laotian collections
together, it is possible to calculate that roughly 3 specimens per 00 km² have been
collected in Lao PDR up until the early 990s. For comparison to neighbouring
countries and to the United Kingdom, see Table .
Table 1. Collection density of herbarium specimens (D.J. Middleton 2003 & pers. comm.).
No. of specimens per 100 km²
Starting around 990, Lao botanists began to intensify their study of the flora,
families for the Flore du Cambodge, du Laos et du Viêt Nam and several broadly
based forestry projects with a taxonomic component, such as the DANIDA funded
Lao Tree Seed Project (LTSP) that formed part of the regional Indochina Tree
Seed Project. A significant output of this project was the manual, Forests and Trees
of the Central Highlands of Xieng Khouang (Lehmann et al. 2003). Other studies
have focussed on plants which yield non-timber forest products such as rattans or
medicinal plants (for example Evans et al. 200, Somsanith Bouamanivong 2005) or
on particular National Protected Areas (Maxwell, 999; Chansamone Phongoudom,
2000). Orchids have been of special interest and there has been a considerable
increase in our knowledge of this group (Schuiteman & De Vogel 2004, Svengsuksa
& Lamxay 2005). This is continuing through the work of the ORCHIS project
(www.orchisasia.org/), a collaboration between the National University of Lao PDR
(NUoL), Centre de Coopération Internationale en Recherche Agronomique pour le
Développement (CIRAD) and the Nationaal Herbarium Nederland. Other botanical
work that is currently under way in Lao PDR includes Biodiversity Informatics and
co-Operation in Taxonomy for Interactive shared Knowledge base (BIOTIK), an
EU funded project concentrating on large tree species, and a number of MSc and
PhD ethnobotanical projects based at NUoL and Uppsala University.
The resurgence of botanical work over the last 5 years has generated a significant
amount of new information and it seems timely to produce a new checklist that
collates as much of this information as possible.
A checklist of the vascular plants of Lao PDR
This new checklist has been generated from a computer database compiled as
part of the Darwin Initiative project Taxonomic Training in a Neglected Biodiversity
Hotspot in Lao PDR.
The information in this checklist derives from several sources. The first was an
electronic version of Latin names contained in Callaghan’s ‘Checklist of Lao Plant
Names’ (Callaghan 2004) and generously donated by the compiler. The second is
the specimen based accounts in the fascicles of the Flore du Cambodge, du Laos et
du Viêtnam that have either been published since 960 or are due to be published in
the near future. For each taxon, at least one specimen per province was selected for
inclusion in the database.
The third source are the records of specimens collected during recent botanical
projects in Lao PDR (see above). In most cases the specimens are lodged in Lao
herbaria with duplicate sets at Paris (P), Edinburgh (E) and Leiden (L). These sources
have been supplemented by electronic downloads of specimen records from each
herbarium’s database as well as specimen based information derived from recent
taxonomic accounts of new species or revisions of families and genera that have
been published in botanical journals.
In addition to the specimen based records, a range of non-specimen based
electronic and printed literature sources have been used. Published and unpublished
accounts for the Flora of Thailand and the Flora of China have been consulted and
taxa that have been noted to occur in Lao PDR included in the checklist. The World
Checklist Series, both published and as available on the internet (www.kew.org/
wcsp/home.do) has also been used. These records are not directly supported by
specimens and are therefore not as reliable. Table 2 (pages 7–2) gives details of the
primary information sources used to verify the names within each family. A full
reference can be found in the bibliography that follows Table 2.
The checklist includes 4,850 species of native, introduced, cultivated and
naturalized vascular plants (see Table 3). Of these, 3,688 are supported by at least
one of the 9,500 specimens in the database – records for the remaining species are
based on the literature sources mentioned above. A list of the species that we know
to be introduced, cultivated or naturalized is included as Table 4 (pages 367–373)
and can be found at the end of the checklist, before the index to the genera.
Table 3. Generalized statistics based on the species recorded in this checklist.
The checklist is derived from a very incomplete data set. The original Flore générale
de l’Indochine has only been partly revised for the Flore du Cambodge, du Laos et
du Viêtnam and several large families or groups such as the ferns, Annonaceae,
Compositae and Gramineae have yet to be included. As revisions of these families
are completed, then many more species will be added. Additionally the majority of
specimens that have been collected in Lao PDR are deposited in Paris and only a
small proportion of these specimens have been databased.
The specimen records provide some indication for the distribution of each species
within Lao PDR and for the number of species documented from each province.
Figure shows the number of species in this checklist recorded from each province.
The floras of the four northwestern provinces of Bokeo, Louang Namtha, Oudomxai
and Phongsali and the southeastern province of Xekong are very poorly represented
within the checklist. This is probably due to their remoteness from the main travel
routes in the early 20th century when collectors such as Poilane were active and the
relatively few projects that have been active since 990. Khammouan and Champasak
have the highest numbers due to the presence of significant National Protected Areas
(NPAs) and recent botanical projects that have focussed on those areas.
The spore-bearing plants, the gymnosperms and the angiosperms are presented
separately. Though these groups have little support in modern phylogenetic
classifications they are used in the layout of most herbaria and individual botanists
tend to specialize in only one of these groups.
Within these three groups, the families are listed in alphabetical order, then
the genera are alphabetical in each family and the species within each genus. The
families, and the placement of genera in each individual families is broadly consistent
with the Flore du Cambodge, du Laos et du Viêtnam but with some modifications
that reflect recent taxonomic changes. To facilitate the use of this checklist, an
alphabetical list of the genera is given at the end of the checklist and should be used
Accepted names are shown in bold face with their authors. When there is a
basionym, it follows the accepted name in the same paragraph. Synonyms are in
italics and are listed alphabetically, along with their accepted name.
For example, here is part of the account of the genus Meliosma:
Meliosma buchananifolia Merr. = Meliosma henryi subsp. thorelii (Lecomte) Beusekom
Meliosma henryi Diels
Laos: Houaphan: E. Poilane 867 (L). Louangphrabang: C. Thorel 2488 (L).
Meliosma henryi subsp. thorelii (Lecomte) Beusekom – Meliosma thorelii Lecomte – Type:
Louangphrabang, C. Thorel 3483 (holo P).
Meliosma buchananifolia Merr.
Laos: Louangphrabang: C. Thorel 3483 (P – Type of Meliosma thorelii Lecomte).
Figure 1. Numbers of species in each province based on specimen records. Species may occur
in more than one province.
The genus Meliosma, which appears in bold face, is accepted. Millingtonia Roxb.
is a synonym of Meliosma.
Meliosma buchananifolia Merr. is a synonym of Meliosma henryi subsp. thorelii
(Lecomte) Beusekom, as indicated by the equals sign, =.
Province by Poilane and in Louangphrabang by Thorel. Both these specimens are at
the Nationaal Herbarium Nederland, Leiden University Branch (L).
Meliosma henryi subsp. thorelii (Lecomte) Beusekom is an accepted species
which is based on
Meliosma thorelii Lecomte. The type specimen is Thorel’s
collection 3483 which is at the herbarium of the Muséum National d’Histoire
naturelle in Paris (P). The specimen was collected in Louangphrabang and is a
holotype specimen of both Meliosma thorelii Lecomte and Meliosma henryi subsp.
share the same type specimen. Meliosma buchananifolia Merr., on the other hand, is
a heterotypic synonym of Meliosma henryi subsp. thorelii (Lecomte) Beusekom.
It has a different type specimen which is not cited here.
Specimens are cited next, listed by province. The collector’s name, collection
number and herbarium location are given. Collector’s names are reduced to the
first name to save space. For example, all collections by Newman, M.F., Thomas, P.,
Armstrong, K.E., Sengdala, K. & Lamxay, V. are listed as M.F. Newman.
If all the species listed in a genus are synonyms of species in other genera, this
means that the genus does not occur in Lao PDR, for example
Gastonia palmata Roxb. ex Lindl. = Trevesia palmata (Lindl.) Vis.
There are no accepted species of Gastonia in the list so there is currently no
record of the genus in Lao PDR but Gastonia appears in bold face which indicates
that it is an accepted genus with accepted species in other countries. If Gastonia was
a synonym, then it would appear in italics, with its corresponding accepted name
Major literature references used for verifying names of species and
their and occurrence in Lao PDR
The following table summarizes the main literature references that have been
used to verify the presence of a particular taxon within Lao PDR. Major references
are listed first and indicated by ‘.’ In some cases these references may only be
relevant to a single genus. Secondary and subsequent references are indicated by
‘’ or ‘.’ ‘FCLV’ refers to published or, for Apocynaceae and Polygalaceae,
unpublished fascicles in the Flore du Cambodge, du Laos et du Viêtnam. ‘FoT’ refers
to published accounts in the Flora of Thailand. ‘FoC’ with a volume number refers to
from http://hua.huh.harvard.edu/china/mss/alphabetical_families.htm. Published
accounts from the Flora of China are referred to by their first author and year of
publication. Full references can be found in the bibliography that follows this table
and precedes the main checklist.
Table 2. Major literature references used for verifying names and occurrence in Lao PDR.
 – main reference. [2 and 3] – secondary and subsequent references. FCLV – Flore du
Cambodge, du Laos et du Viêtnam. FoT – Flora of Thailand. FoC – Flora of China.
References for checklist bibliography
 Wood & Scotland (2006)  FoC Vol. 19 unpublished draft
 Van Gelderen (1994)
 Govaerts & Frodin (2002)
 FoT Vol. 2(2)
 Smith et al (2006)
 FCLV Vol. 8.  Govaerts (2006) online World Checklist
 Govaerts (2006) online World Checklist
 FCLV Vol. 24
 FCLV Vol. 2.
 Weerasooriya & Saunders (2005)  Meade (2005)
 FCLV draft (under review)
 FoC Vol. 12 unpublished draft
 Frodin & Govaerts (2004)  Jebb (1998)
 FoT Vol. 5(1)
 Livschultz et al (2005)
 FCLV Vol. 14
 Hughes (2007)
 Li Peiqiong & Skvortsov (1999)  Govaerts (2006) online
 FCLV Vol. 22