KEY TO Pothos SPECIES
IN THAILAND AND INDOCHINA
1a. Leaf with petiole expanded and flattened, the leaf resembling
that of many Citrus...2
1b.Leaf with petiole slender, canaliculate. . . . . . . . 11
2a. Stipe of spadix sharply bent at anthesis, fertile portion of
spadix held adjacent to peduncle. . . . . . . . . . . 9. P.
2b.Stipe of spadix ± straight at anthesis . . . . . . .
3a. Fertile portion of spadix long slender-cylindrical, often slightly
tortuose; leaves of flowering shoots with petiole at least eight
times longer than lamina. . . . 8. P.
3b.Fertile portion of spadix globose, obtuse-ellipsoid or stout
cylindrical, if stout cylindrical then straight and leaves of flowering
shoots with petiole shorter than lamina . . 4
4a. Spadix stout cylindrical; central Vietnam . . . . . . 2.
4b.Spadix globose to obtuse-ellipsoid; various localities . . .
. . 5
5a. Stipe of spadix short (no more than twice as long as fertile
portion of spadix) . . 6
5b.Stipe of spadix long (more then three times as long as fertile
portion of spadix) . 7
6a. Flowering shoots arising at many leaf axils along long pendent
fertile shoots, inflorescences
thus often very numerous; spathe purple, fertile portion of spadix
cream 9. P. scandens
6b.Flowering shoots arising at only the distal-most leaf axils
of short spreading fertile shoots, inflorescences thus rather few;
spathe green, fertile portion of spadix white to yellow. . . . .
. . . . . . 1. P. chinensis
7a. Fertile portion of spadix very small (5 mm diam. or less at
anthesis) . . . 8
7b.Fertile portion of spadix moderate to large (10 mm diam. or
more at anthesis) . . 9
8a. Peduncle 25 40 x 0.5 1 mm, slender; stipe10
18 x 0.23 0.75 mm, very slender. . . . . . . . . . . 5.
8b.Peduncle 0 3 ( 5) x c. 1 mm, stout; stipe 10
12 x 1 1.25 mm, stout . 7. P.
9a. Spathe white, fertile portion of spadix yellow; peninsular
Thailand, central & southern
Vietnam, ?Cambodia . . . . . . . . . 10
9b.Spathe green, fertile portion of spadix purple; north Vietnam,
?China. . . 4. P. grandis
10a. Petiole twice or more the length of lamina, bright to mid-green,
congested-distichous; juvenile stage with weakly angled to subterete
stems, leaves bright green, spreading to loosely appressed to substrate;
peninsular Thailand . . . . . 6. P.
10b.Petiole half or less the length of lamina, grey-green, spaced
out; juvenile stage with compressed, winged, rectangular stems,
leaves blue- to grey-green, tightly appressed tosubstrate; central
& southern Vietnam, ?Cambodia . . . 3. P.
11a. Spadix with flowers densely clustered, the whole appearing
uniformly cylindrical . 12
11b.Spadix with flowers scattered along a slender axis . . . .
10. P. curtisii
12a. Spathe deeply cucullate, deep purple; inflorescence carried
below the flowering shoot on a sharply deflexed peduncle. . . .
. . . . 11. P. kingii
12b.Spathe never as above; inflorescence variously orientated .
. . . 13
13a. Spathe lorate, mid-green; spadix stipitate; peduncle less
than 60 mm long 13. P. lorispathus
13b.Spathe lanceolate to triangular, variously coloured; spadix
sessile or stipitate, if stipitate then peduncle more than 100 mm
long . . . . . . . 14
14a. Peduncle 15 50 mm; spathe lanceolate, 25 100
x 10 40 mm; spadix sessile. . . . . . . . . . 12. P.
14b.Peduncle 100 190 mm; spathe triangular, 60 90
x 15 20 mm; spadix stipitate. . . . . . . . . . 14. P.