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A preliminary assessment of the conservation status of the genus Aloe L. In Madagascar

December 2014
Bradleya 32:81-91

DOI:10.25223/brad.n32.2014.a1

Authors:

Solofo Eric Rakotoarisoa

University of Antananarivo

Ronell R. Klopper

South African National Biodiversity Institute

The island of Madagascar harbours 128 species (161 taxa) of Aloe L., which are all endemic to this biodiversity hotspot. Most Malagasy aloes have very restricted distribution ranges and are represented by small populations. Madagascan aloes are very popular in horticulture and an important part of the ornamental plant export industry. The aloes of Madagascar are prone to human pressures that affect the degradation of their natural habitats and their survival. However, there has not been a treatment to assess the conservation status of the Malagasy aloes. Here, for the first time, we aim to provide a risk assessment and make available preliminary conservation statuses for all the known aloes of Madagascar. Specimen information from different herbaria and different websites have been gathered and compiled into a BRAHMS database. The Conservation Assessment Tool was used for data analysis during the conservation assessments. It was found that around 39% of Madagascan aloes are threatened, with only 4% being Least Concern. Of great significance is the fact that almost 50% of the aloes in Madagascar are regarded as Data Deficient, likely leading to a huge underestimate of the percentage of threatened aloes. Further research into Data Deficient taxa and a comprehensive conservation assessment for all the aloes of Madagascar is required. These results will inform priorities in conservation projects concerning aloes and the areas where they occur.

Aloe suzannae from southern Madagascar is one of only two Madagascan aloes currently included in the IUCN Red Data List. It is listed as Critically Endangered. Photograph: S.E. Rakotoarisoa.

…

Aloe helenae from southeastern Madagascar is currently listed as Critically Endangered on the IUCN Red Data List. Photograph: D. Rabehevitra.

…

Aloe hoffmannii from central Madagascar is only known from the area of its type locality and is assessed here as Critically Endangered. Photograph: S.E. Rakotoarisoa.

…

Aloe ivakoanyensis is a berried aloe described in 2012 from the Ivakoany Massiff in southeastern Madagascar and was assessed as Critically Endangered at the time. Photograph: R. Letsara.

…

Aloe madecassa is endemic to the Antananarivo region in east-central Madagascar and is here assessed as Vulnerable. Photograph: S.E. Rakotoarisoa.

…

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Bradleya 32/2014

Summary: The island of Madagascar harbours

128 species (161 taxa) of Aloe L., which are all en-

demic to this biodiversity hotspot. Most Malagasy

aloes have very restricted distribution ranges and

are represented by small populations. Madagas-

can aloes are very popular in horticulture and an

important part of the ornamental plant export in-

dustry. The aloes of Madagascar are prone to

human pressures that affect the degradation of

their natural habitats and their survival. How-

ever, there has not been a treatment to assess the

conservation status of the Malagasy aloes. Here,

for the first time, we aim to provide a risk assess-

ment and make available preliminary conserva-

tion statuses for all the known aloes of

Madagascar. Specimen information from different

herbaria and different websites have been gath-

ered and compiled into a BRAHMS database. The

Conservation Assessment Tool was used for data

analysis during the conservation assessments. It

was found that around 39% of Madagascan aloes

are threatened, with only 4% being Least Con-

cern. Of great significance is the fact that almost

50% of the aloes in Madagascar are regarded as

Data Deficient, likely leading to a huge underes-

timate of the percentage of threatened aloes. Fur-

ther research into Data Deficient taxa and a

comprehensive conservation assessment for all

the aloes of Madagascar is required. These results

will inform priorities in conservation projects con-

cerning aloes and the areas where they occur.

Zusammenfassung: Die Insel Madagaskar ist die

Heimat von 128 Arten (161 Taxa) von Aloe L., und

alle sind in diesem Biodiversitäts-Hotspot en-

demisch. Die meisten madagassischen Aloen

haben eine sehr beschränkte Verbreitung und

sind durch kleine Populationen gekennzeichnet.

Madagassiche Aloe-Arten sind im gärtnerischen

Bereich geschätzt, und sie stellen einen wichtigen

Teil der Zierpflanzenexportindustrie dar. Die

Aloen von Madagaskar werden durch anthropo-

gene Faktoren bedrängt, welche zur Degradation

ihrer Standorte führen und das Überleben

gefährden. Bisher gab es jedoch keine formelle

Beurteilung des Gefährdungsstatus' der mada-

gassichen Aloen. Hier versuchen wir für das erste

Mal überhaupt eine Beurteilung der Risiken, und

wir machen für alle bekannten madagassischen

Aloen eine vorläufige Einschätzung des

Gefährdungsstandes. Es wurden Angaben zu

Belegen aus verschiedenen Herbarien und von

verschiedenen Webseiten zusammengetragen und

in eine BRAHMS-Datenbank zusammengestellt.

Das Werkzeug für die Beurteilung des

Gefährdungsstatus wurde dann während der

Evaluation zur Datenanalyse verwendet. Es

zeigte sich, dass rund 39% der madagassischen

Aloe-Arten gefährdet sind, und nur 4% gehören in

die Kategorie "Least Concern". Von besonderer

Wichtigkeit ist die Tatsache, dass für fast 50% der

madagassischen Aloen unzureichende Angaben

vorhanden sind, was wahrscheinlich zu einer

deutlichen Unterschätzung des Prozentsatzes

gefährderter Aloen führt. Es braucht weitere Un-

Bradleya 32/2014

pages 81–91

A preliminary assessment of the conservation status of the

genus Aloe L. in Madagascar

Solofo E. Rakotoarisoa1, Ronell R. Klopper2,3 & Gideon F. Smith2,4,5

1 Millennium Seed Bank Project, Royal Botanic Gardens Kew, Kew Madagascar Conservation

Centre, Lot II J 131 B, Ambodivoanjo, Ivandry, Antananarivo, Madagascar.

(email: ESRakotoarisoa.rbgkew@moov.mg).

2 Biosystematics Research and Biodiversity Collections Division, South African National

Biodiversity Institute, Private Bag X101, Pretoria, 0001 South Africa.

(email: R.Klopper@sanbi.org.za).

3 H.G.W.J. Schweickerdt Herbarium, Department of Plant Science, University of Pretoria,

Pretoria, 0002 South Africa.

4 Centre for Functional Ecology, Departamento de Ciências da Vida, Universidade de Coimbra,

3001-455 Coimbra, Portugal. (email: smithgideon1@gmail.com)

5 Department of Botany, P.O. Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth,

6031 South Africa.

tersuchungen dieser "Data Deficient"-Taxa sowie

umfassende Einschätzungen des Gefährdungssta-

tus' aller madagassichen Aloen. Diese Resultate

ergeben die Grundlage für die Prioritätensetzung

bei Schutzprojekten für Aloe sowie die Gegenden,

in welchen sie vorkommen.

Introduction

In Madagascar, the genus Aloe L. comprises

128 species and 161 taxa of which all are en-

demic to the island (Aloes of the World Data-

base, 2014). These plants are highly sought-after

by both foreign and Malagasy horticulturists.

Aloes represent 5% of exported succulent orna-

mental plants, which in turn constitutes 86% of

the total ornamental plants exportation from

Madagascar (Rasoanaivo et al., in press).

Scientists have been fascinated by Malagasy

aloes for just over 150 years: the first collection

of an aloe in Madagascar was made in 1848 by

Boivin [Aloe occidentalis (H.Perrier) L.E.Newton

& G.D.Rowley, Boivin, L.H. 2336 (P)]. The first

treatment of the genus in Madagascar was pro-

duced by Perrier de la Bathie in 1926 (Perrier de

la Bathie, 1926), followed by an updated Flora

treatment in 1938 (Perrier de la Bathie, 1938a

& b). The third treatment of the aloes of Mada-

gascar followed in 1966 when Reynolds produced

his epic second volume on the genus (Reynolds,

1966). Thereafter, apart from the inclusion of

several aloes in a two volume work on the suc-

culent and xerophytic plants of Madagascar by

Rauh (Rauh, 1995, 1998), only small publica-

tions describing new aloes appeared. Between

2000 and 2010, approximately 54 new taxa were

validly described and eight new combinations

published. A further 19 new names, which are

now treated as synonyms, were also published

during this time (Aloes of the World Database,

2014). The latest large-scale treatment of Mada-

gascan aloes is that of Castillon & Castillon

(2010). Since the appearance of this book, a fur-

ther fifteen new aloes and two new combinations

were published (Aloes of the World Database,

2014) (see Table 1).

82 Bradleya 32/2014

Figure 1. Aloe suzannae from southern Madagascar is

one of only two Madagascan aloes currently included in

the IUCN Red Data List. It is listed as Critically En-

dangered. Photograph: S.E. Rakotoarisoa.

Figure 2. Aloe helenae from southeastern Madagascar

is currently listed as Critically Endangered on the IUCN

Red Data List. Photograph: D. Rabehevitra.

Bradleya 32/2014

In Madagascar, research on the genus proves

to be challenging, mainly because of the paucity

of herbarium material held locally: 95 taxa are

represented by only one collection, and 20 species

were not collected during the past 40 years. The

question remains whether these aloes have dis-

appeared in nature, or if they are only rarely col-

lected by botanists.

Except for a few species (less than 10), the

Malagasy aloes have very restricted distribution

ranges. Furthermore, most species are repre-

sented by a small population. These factors make

the genus more vulnerable to human pressures

such as bush fires and illegal collecting of wild

plants for commercial purposes. In addition, dif-

ficulty of regeneration of populations constitutes

a real danger of extinction of aloes. The majority

of aloes (43%) are found on the Malagasy high

plateau and only 7% are recorded from the East.

Much of the natural vegetation on the central

high plateau has been destroyed for rice cultiva-

tion and the remaining grasslands are burned an-

nually to provide grazing for zebu (cattle), which

play a huge part in the life and rituals of the

Malagasy people (Rauh, 1995). The aloes of

Madagascar are thus prone to human pressures

that affect the degradation of their natural habi-

tats and their survival.

All species of Aloe [except for A. vera (L.)

Burm.f] appear on the Appendices of the Conven-

tion on the International Trade in Endangered

Species of Wild Fauna and Flora (CITES). This

means that trade in aloes is controlled to prevent

utilisation that would be incompatible with their

survival. Of the 21 aloe species listed on Appendix

I (CITES, 2014), a total of 17 are Malagasy

species. This is an indication of the huge threat

to the conservation of these aloes. All other aloes

are listed on Appendix II (CITES, 2014).

Currently, only two Madagascan aloe species

appear on the International Union for Conserva-

tion of Nature (IUCN) Red Data List, namely Aloe

suzannae Decary (Figure 1) (Smith & Swartz,

1997, 1999; Smith et al., 1999) and A. helenae

Danguy (Figure 2), and both are assessed as Crit-

ically Endangered D (IUCN, 2014). This list is not

up to date as far as the aloes of Madagascar are

concerned, owing to the vast number of new aloes

described from this island in the past few

decades. Another reason is the absence of a full

assessment of the conservation statuses of Mala-

gasy aloes. Currently, three Madagascan aloes

have become extinct in the wild (namely A. oligo-

phylla Baker, A. schilliana L.E.Newton & Row-

ley and A. silicicola H.Perrier), while numerous

species are threatened with extinction through

the destruction of their natural habitats (Castil-

lon & Castillon, 2010).

Conservation assessments have become in-

creasingly essential tools to provide a framework

for conservation planning, management, moni-

toring and decision-making (Callmander et al.,

2005; Rodrigues et al., 2006). For this reason the

World Conservation Congress, held in Thailand

in 2004, mandated the development of new appli-

cations for Red Lists in national and interna-

tional legislation, development policies,

conservation planning and scientific research (Ro-

drigues et al., 2006). Even though plants play an

essential role in ecosystem structure as the basis

of all life on earth, only a small percentage of

plants have been assessed globally (Callmander

et al., 2005). Therefore, Target 2 of the Global

Strategy for Plant Conservation (GSPC) calls for

“an assessment of the conservation status of all

Figure 4. Aloe bernadettae from southeastern Mada-

gascar is a Data Deficient species that used to be com-

mon, but has now seemingly become scarce.

Photograph: R. Letsara.

Figure 3. Number of Aloe taxa in the different IUCN

categories. (EW: Extinct in the Wild; CR: Critically En-

dangered; EN: Endangered; VU: Vulnerable; NT: Near

Threatened; LC: Least Concerned; DD: Data Deficient)

84 Bradleya 32/2014

known plant species, as far as possible, to guide

conservation action” (http://www.cbd.int/gspc/tar-

gets.shtml). One way of achieving this would be

for countries to focus on national endemics that

are obvious priorities (Callmander et al., 2005).

This approach is especially relevant to the Mada-

gascan aloes, as they are all endemic to this is-

land.

Here, for the first time, we aim to provide a

risk assessment and make available preliminary

conservation statuses for all the known aloes of

Madagascar.

Materials and methodology

To assemble all the necessary data from

herbarium collections, visits were made to vari-

ous herbaria including the National Herbarium,

Pretoria (PRE), and those of the Botanical and Zo-

ological Park of Tsimbazaza (TAN) and the Royal

Botanic Gardens, Kew (K). For those herbaria

where important Malagasy specimens are held

and that could not be visited, available data were

downloaded through the Global Biodiversity In-

formation Facility (GBIF; http://www.gbif.org/) or

Sonnerat (http://coldb. mnhn.fr/colweb/form.do

?model=SONNERAT) websites. The final dataset

included records from the following herbaria:

HBG, K, MO, P, PRE and TAN (herbarium

acronyms follow Holmgren et al., 1990). For new

taxa where herbarium specimens are not avail-

able in the herbaria of Madagascar, information

on geographical references, as mentioned in the

protologues, was used.

Scientific names of all taxa were updated by

referring to the list published by Klopper et al.,

(2013) and Castillon & Castillon (2010). This

treatment therefore follows all recommendations

by Castillon & Castillon (2010) on synonymy. Hy-

brids (A. ×anosyana J.-P.Castillon, A. ×philippei

J.-B.Castillon, A. ×imerinensis Bosser) were also

eliminated from the list. Further updating was

based on taxonomic revisions and new descrip-

tions of the Malagasy aloes that were published

after 2010 (see Table 1).

Improvements to the georeferencing of espe-

cially older specimens were conducted to attain

better accuracy for the analyses. This was

achieved by manually checking individual collec-

tions and correcting all wrong localities and grid

references.

ArcView 3.3 and the Conservation Assess-

ment Tool (CAT) were used for the conservation

status analysis. Extent of occurrence (EOO) and

area of occupancy (AOO) were calculated auto-

matically by the CAT. Default values for grid cells

of 2 × 2km, as suggested by the IUCN (2001),

were used for all situations. As the population

size of each species is not yet well defined (possi-

bly being either greater or smaller than 2 × 2km),

EOO values were used for the analysis in this

preliminary assessment.

Figure 6. Aloe ivakoanyensis is a berried aloe described

in 2012 from the Ivakoany Massiff in southeastern

Madagascar and was assessed as Critically Endangered

at the time. Photograph: R. Letsara.

Figure 5. Aloe hoffmannii from central Madagascar is

only known from the area of its type locality and is as-

sessed here as Critically Endangered.

Photograph: S.E. Rakotoarisoa.

Bradleya 32/2014

Taxon Citation

Aloe antoetrana J.-B.Castillon CactusWorld 29(1): 53 (2011)

Aloe bernardii J.-P.Castillon International Cactus Adventures 89: 25 (2011)

Aloe erythrophylla subsp. major J.-B.Castillon CactusWorld 29(1): 54 (2011)

Aloe mottramiana J.-B.Castillon CactusWorld 29(4): 218 (2011)

Aloe spinitriaggregata J.-B.Castillon International Cactus Adventures 90: 2 (2011)

Aloe ×anosyana J.-P.Castillon Adansonia 34(1): 20 (2012)

Aloe analavelonensis Letsara, Rakotoarisoa & Almeda Malagasy Nature 6: 49 (2012)

Aloe beankaensis Letsara, Rakotoarisoa & Almeda Malagasy Nature 6: 49 (2012)

Aloe divaricata subsp. tulearensis (McCoy & Lavranos)

J.-P.Castillon Adansonia 34(1): 19 (2012)

Aloe divaricata subsp. vaotsohy (Decorse & Poisson)

J.-P.Castillon Adansonia 34(1): 18 (2012)

Aloe ivakoanyensis Letsara, Rakotoarisoa & Almeda Malagasy Nature 6: 52 (2012)

Aloe mandrarensis J.-P.Castillon CactusWorld 30(3): 168 (2012)

Aloe virgineae J.-P.Castillon CactusWorld 30(3): 164 (2012)

Aloe conifera subsp. pervagata J.-B.Castillon CactusWorld 31(1): 45 (2013)

Aloe fievetii subsp. johanis-baptistei J-B.Castillon CactusWorld 31(1): 47 (2013)

Aloe graniticola Rebmann Cactus & Succulentes 5(2): 52 (2013)

Aloe delicatifolia J.-B.Castillon CactusWorld 31(4): 259 (2013)

Table 1. List of new taxa and new combinations published after 2010.

Table 2. List of species with infraspecific ranks that were only assessed on species level.

Species Infraspecific taxa not assessed separately

Aloe antandroi (Decary) H.Perrier subsp. toliarana J.-B.Castillon

Aloe bulbillifera H.Perrier var. paulianae Reynolds

Aloe compressa H.Perrier var. paucituberculata Lavranos

var. schistophila H.Perrier

Aloe conifera H.Perrier subsp. pervagata J.-B.Castillon

Aloe erythrophylla Bosser subsp. major J.-B.Castillon

Aloe descoingsii Reynolds subsp. vaotsohy (Decorse & Poiss.) J.-P.Castillon

Aloe fievetii Reynolds

subsp. johannis-baptistei J.-B.Castillon

var. altimatsiatrae (Rebmann) J.-B.Castillon

var. ambatofinandrahanensis J.-B.Castillon

Aloe haworthioides Baker var. aurantiaca H.Perrier

Aloe imalotensis Reynolds var. longeracemosa J.-B.Castillon

Aloe laeta A.Berger var. maniaensis H.Perrier

Aloe sakarahensis Lavranos & M.Teissier subsp. pallida (Rauh & Mangelsdorff) Lavranos & M.Teissier

Aloe trachyticola (H.Perrier) Reynolds var. multifolia J.-B.Castillon

Aloe vaombe Decorse & Poiss. var. poissonii Decary

Aloe versicolor Guillaumin var. steffanieana (Rauh) J.-B.Castillon & J.-P.Castillon

86 Bradleya 32/2014

After preliminary results were obtained,

minor corrections were necessary for certain taxa

because misidentification of some specimens in-

fluenced the distributions. All these cases were

treated and corrected individually. Where species

had already been assessed by their authors (some

newly described species: A. virgineae J.-P.Castil-

lon, A. analavelonensis Letsara, Rakotoarisoa &

Almeda, A. beankaensis Letsara, Rakotoarisoa &

Almeda, A. ivakoanyensis Letsara, Rakotoarisoa

& Almeda, Aloe delicatifolia J.-B.Castillon) or

IUCN assessors (A. helenae and A. suzannae), we

have retained their conservation status as such.

In the current study, certain species with infra-

specific ranks (e.g. subspecies and varieties) were

only assessed to species level if the differences be-

tween the lower ranks were not evident on the

specimens, or a large part of the collections were

only identified up to species level (see Table 2).

Results

Data from a total of 1630 collections were as-

sembled and compiled into a Botanical Research

and Herbarium Management System (BRAHMS)

database. After updating the identification of

some specimens, and eliminating those that were

unidentified or not geo-referenced, a total of 759

unique botanical records remained that were used

in the analysis. These 759 botanical records in-

clude 86 specimens collected by the Millennium

Seed Bank Project (MSBP), some of which are al-

ready deposited in herbaria in Madagascar or

elsewhere, as well as 110 specimens from PRE,

452 from P (43 downloaded from GBIF), 175 from

TAN, 95 from MO (through GBIF), 13 from HBG

(through GBIF) and 69 from K. (Several botanical

records had duplicate specimens in more than one

of these herbaria, therefore the total number of

specimens exceeds the number of unique collec-

tion records.)

After eliminating all taxa to be excluded from

the analysis (synonyms, hybrids and unidentified

infraspecific taxa), a total of 141 taxa remained.

Of these 141 taxa, a total of 55 (39.3%) are re-

garded as threatened (i.e. in the categories Criti-

cally Endangered, Endangered or Vulnerable).

The taxa of conservation concern are distributed

among the different Red List categories as follows:

3 (2.1%) are Extinct in the Wild (EW); 14 (9.9%)

Critically Endangered (CR); 30 (21.3%) Endan-

gered (EN); 11 (7.8%) Vulnerable (VU); 7 (5%)

Near Threatened (NT); and 70 (49.6%) Data Defi-

cient (DD). A further 6 taxa (4.3%) are Least Con-

cern (LC) (see Figure 3). Percentages given reflect

the percentage of the total number of taxa

analysed (see Table 3 for a full list of taxa and

their conservation statuses).

Discussion and future prospects

The number of taxa in the DD category is very

high because most of these aloes are represented

by a single or only two collections. This can be

Figure 7. Aloe madecassa is endemic to the Antana-

narivo region in east-central Madagascar and is here as-

sessed as Vulnerable. Photograph: S.E. Rakotoarisoa.

Figure 8. Aloe namorokaensis from northwestern

Madagascar is a Data Deficient species that is only

known from the type locality. Photograph: Conservatoire

owing to several factors, but the most common is

the fact that few botanists collect aloe material as

it demands more preparatory treatment and takes

a lot of time to make proper herbarium specimens

of these fat-leaved plants. A total of 69% of Mada-

gascan aloes in the DD category are only repre-

sented by the type specimen. These include taxa

that have been newly described since the 1990s

and also a few that have not been collected for

more than 100 years. The remaining DD aloes are

known from only one or two localities and CAT are

thus unable to calculate EOO and AOO values.

For the first group, the DD status can easily be

explained by their recent discovery and the fact

that only a few collections have been made since.

However, the problem remains for aloes that were

described long ago, but where collection numbers

are two or less. These taxa might be very rare, ex-

tinct in the wild or access to the populations is

very difficult [e.g. Aloe prostrata (H.Perrier)

L.E.Newton & G.D.Rowley].

The difficulty of assessing taxa with few spec-

imens or only old material is a frequent problem

and may be relevant to as much as 20% of the

world’s plant diversity. If all these taxa are as-

sessed as DD, then the result would be a huge un-

derestimate of the percentage of threatened

plants globally. This situation is not very helpful

in directly informing conservation planning

processes. Such a high proportion of species in the

DD category hampers the achievement of the

GSPC targets for 2020 (Callmander et al., 2005).

For this reason, Callmander et al., (2005) sug-

gested that the DD category should be applied

only in cases of unresolved taxonomy or uncertain

locality information, and proposed rapid methods

for evaluating species with very limited numbers

of specimens or only old material. This approach

is aimed towards achieving Target 2 of the GSPC.

Bradleya 32/2014

Figure 9. Aloe newtonii from south-central Madagascar

is named after Prof. Len Newton. It is here assessed as

Endangered. Photograph: S.E. Rakotoarisoa.

Figure 10. Aloe suarezensis from the Antsiranana re-

gion in northern Madagascar is the only Madagascan

aloe with fine hairs on the flowers and pedicels. It is here

assessed as Endangered.

Photograph: S.E. Rakotoarisoa.

Table 3. (Overleaf)

Conservation statuses of Madagascan aloes.

Taxa in threatened categories

(CR: Critically Endangered; EN: Endangered; VU:

Vulnerable) are shaded and have status and EOO

value in italics.

DD: Data Deficient;

NT: Near-Threatened;

LC: Least Concerned;

EW: Extinct in the Wild;

EOO: extent of occurrence

88 Bradleya 32/2014

Taxon IUCN

Status

EOO

value(km2)

Aloe acutissima H.Perrier subsp.

acutissima var. acutissima VU 15495.83

Aloe acutissima H.Perrier subsp.

itampolensis Rebmann DD

Aloe acutissima H.Perrier var.

antanimorensis Reynolds VU7567.27

Aloe acutissima H.Perrier var.

fiherenensis J.-B.Castillon CR 71.81

Aloe acutissima H.Perrier var.

isaloana J.-B.Castillon DD

Aloe albiflora Guillaumin DD

Aloe albostriata T.A.McCoy,

Rakouth & Lavranos DD

Aloe alfredii Rauh DD

Aloe ambositrae J.-P.Castillon DD

Aloe ambrensis J.-B.Castillon DD

Aloe ampefyana J.-B.Castillon DD

Aloe analavelonensis Letsara,

Rakotoarisoa & Almeda VU

Aloe andringitrensis H.Perrier EN 241.88

Aloe anivoranoensis (Rauh &

Hebding) L.E.Newton &

G.D.Rowley DD

Aloe ankaranensis Rauh &

Mangelsdorff DD

Aloe antandroi (Decary) H.Perrier NT

Aloe antoetrana J.-B.Castillon DD

Aloe antonii J.-B.Castillon EN 2914.51

Aloe antsingyensis (Leandri)

L.E.Newton & G.D.Rowley EN 550.7

Aloe argyrostachys Lavranos,

Rakouth & T.A.McCoy DD

Aloe aurelienii J.-B.Castillon DD

Aloe bakeri Scott-Elliot NT

Aloe beankaensis Letsara,

Rakotoarisoa & Almeda LC

Aloe belavenokensis

(Rauh & Gerold) L.E.Newton &

G.D.Rowley DD

Aloe bellatula Reynolds VU 9035.22

Aloe berevoana Lavranos DD

Aloe bernadettae J.-B.Castillon DD

Aloe bernardii J.-P.Castillon DD

Aloe betsileensis H.Perrier EN 558.69

Aloe boiteaui Guillaumin DD

Aloe bosseri J.-B.Castillon DD

Aloe bruynsii P.I.Forst. DD

Aloe buchlohii Rauh DD

Aloe bulbillifera H.Perrier NT

Aloe calcairophila Reynolds CR 2.57

Taxon IUCN

Status

EOO

value(km2)

Aloe capitata Baker var.

angavoana J.-P.Castillon EN 205.22

Aloe capitata Baker var. capitata EN 628

Aloe capitata Baker var.

quartziticola H.Perrier NT

Aloe capitata Baker var. silvicola

H.Perrier EN334.91

Aloe castilloniae J.-B.Castillon DD

Aloe charlotteae J.-B.Castillon DD

Aloe cipolinicola (H.Perrier)

J.-B.Castillon & J.-P.Castillon EN

Aloe citrea (Guillaumin)

L.E.Newton & G.D.Rowley DD

Aloe compressa H.Perrier VU 18782.05

Aloe conifera H.Perrier EN 4517.56

Aloe cryptoflora Reynolds DD

Aloe cyrtophylla Lavranos DD

Aloe darainensis J.-P.Castillon DD

Aloe decaryi Guillaumin DD

Aloe decorsei H.Perrier DD

Aloe delicatifolia J.-B.Castillon EN

Aloe delphinensis Rauh DD

Aloe deltoideodonta Baker subsp.

amboahangyensis Rebmann DD