Revision of the Genus Pandanus Srkkman, Part 27 
Pan dan us Novelties from Madagascar 
Harold St. John 1 
At the beginning of the eighteenth century 
Pandanus was found growing naturally on 
Madagascar. The first species from there were 
described by du Petit Thouars. Subsequent dis- 
coveries revealed that it was one of the three 
great centers of the genus, with 63 species. 
With support from a grant by the National 
Science Foundation, the writer spent ten weeks 
in 1961 exploring the island for Pandanus. 
First a map showing all known localities for 
the accepted species was prepared. Then, three 
expeditions were undertaken in search of Pan- 
danus , the route in all cases being to regions 
from which no previous collector had obtained 
specimens. As the genus is widespread on the 
island, the result of the search was the discovery 
of numerous additional species. Several of them 
are here described as new. 
Section Acanthostyla 
Pandanus columnaris sp. nov. (sect. Acantho- 
styla') 
Figs. 247, 253 bottom , left and right. 
nom. vern. : "fandran.” 
diagnosis holotypi: Arbor columnaris, trunco 
20 m alto 25 cm diametro, cortice paliide brunneo cum 
spinis conicis, radicibus fulturosis nullis vel paucis 
eis 20 cm longis 1.5 cm diametro paliide b runnels et 
spinosis, corona anguste cylindrica in apice cum foliis 
magnis in spiris cleinde infra trunco cum ramulis 
lateralibus secundariis brevibus subaequalibus cum 
foliis minoribus angustis, foliis terminalibus 2 m et 
plus longis proxima basem 24 cm latis crassiter 
coriaceis supra midnervum sulcatis 2-plicatis, in sec- 
tione medial! cum 98 nervis parallelis secundariis in 
dimidio quoque proxima basem infra nervis tertiis 
evidentis et reticulis breviter oblongis formantibus, 
laminis ligulatis, in basi ex 16-17 cm marginibus cum 
spinis 3-5 mm longis 4-10 mm separatis basi incras- 
sata sed apice subulato inferioribus recurvatis su- 
perioribus adscendentibus, midnervo infra ex 19 cm 
cum spinis 3 mm longis 4-8 mm separatis late 
conicis sed apice subulato recurvato, in sectione 
mediali marginibus cum aculeis 2-3 mm longis 3-10 
1 B. P. Bishop Museum, Honolulu, Hawaii 96819- 
Manuscript received May 16, 1963. 
mm separatis subulatis adscendentibus, midnervo infra 
cum aculeis 1.5-2. 5 mm longis 2-7 mm separatis 
subulatis adpresse adscendentibus, ramulis lateralibus 
medial is brevibus 2-2.5 mm diametro brunneis in toto 
spinosis, foliis 1-1.2 m longis 18-22 mm latis 
graciliter coriaceis supra obscure olivaceis infra 
paliide viridibus et glaucis subcurvatis non cassatis 
supra late V-sulcati§ 2-plicatis et ad apicem plicis 
acute serrulatis in sectione mediali cum 21 nervis 
parallelis secundariis nervis tertialis nullis lamina 
ligulata in apice trigono subulato diminuenti eo 10 cm 
ex apice 6-10 mm lato basi inermi amplexicauli alba, 
marginibus basi ex 15 cm cum aculeis subulatis 0.5- 
1.2 mm longis 4-10 mm separatis vel cum serrulis 
albis cum apicibus brunneis, midnervo infra ad 
medium vel ultra inermi, in sectione mediali mar- 
ginibus cum serrulis 0. 2-0.9 mm longis 2-4 mm 
separatis albis, midnervo infra inermi vel cum 
serrulis 0.1-0. 2 mm longis 7-12 mm separatis albis, 
in apice marginibus et midnervo infra cum serrulis 
0.3-0. 5 mm longis 2-3 mm separatis albis, infruc- 
tescentia non visa sed dicet "in ramulis lateralibus et 
cum spicis luteis,” phalangibus 20-22 mm longis 
10-15 mm latis 8-11 mm crassis obovoideis com- 
pressis 4-7-carpellatis parte % super?, libera, stylis 
6-7 mm longis acicularibus arcuatis in basi conica 
brevi affixis, stigmatibus 6-7 mm longis linearibus 
proximalibus papillosis, endocarpio in parte % supera 
osseoso brunneo lateribus 1—1.5 mm crassis intra 
laevibus et lucidis, seminibus 3.5-5 mm longis 
ellipsoideis, mesocarpio apicali 3 mm longo cum 
fibris validibus longitudinalibus, mesocarpio basali 
fibroso et carnoso. 
diagnosis of holqtype: Tree, columnar, 
the trunk 20 m tall, 25 cm in diameter; bark 
light brown, conic spiny; prop roots none or 
few and 20 cm long, 2.5 cm in diameter, light 
brown, spiny; crown narrowly cylindric, the 
apex with spirals of large leaves, but below 
them half or more than half of the length of 
the trunk with short secondary branchlets, all 
subequal, and bearing numerous small, narrow 
leaves; terminal leaves in spirals at apex of 
trunk, more than 2 m long, 24 cm wide near 
the base, thick coriaceous, furrowed above the 
midrib and the sides pleated, near the midsec- 
tion with 98 parallel secondary veins in each 
half, near the base below the tertiary cross veins 
visible, forming short oblong meshes; blade 
104 
