Posted March 13, 1996 (Indented key transfered to bracketed HTML key with by E.J.Gouda June 16, 1999)
1A. Spadix-appendage terete or clavate, obtuse or sometimes
capitate at the apex, shorter than blade of the spathe (6)
1B. Spadix-appendage filiform, long-exserted from the spathe
2A. Normal leaves 2; spadix-appendage 10-15 cm long, 2.5-3.5
times as long as the spathe tube; terminal leaflet not longer than lateral ones A.
negishii
2B. Normal leaf solitary; spadix-appendage longer than 15 cm
3A. Terminal leaf much shorter than the adjacent lateral ones;
psudostem more than 40 cm long; spathe nearly green A. heterophyllum
3B. Terminal leaf as large or larger than adjacent lateral ones; psudostem nearly
wanting; spathe dark reddish purple
4A. Spathe-blade with a T-shaped white mark inside; scape rising
near base of petiole A. kiushianum
4B. Spathe-blade without a T-shaped white mark inside; scape arising above base of
petiole
5A. Enlargement at base of spadix-appendage densly wrinkled A.
thunbergii
5B. Enlargement at the base of spadix-appendage smooth A. urashima
6A. (1) Spadix-appendage gradually passing into
the floriferous part; spathe and spadix-appendage different in staminate and pistillate
plants A. heterocephalum
6B. Spadix-appendage truncate at base; spathe and spadix-appendage equal or nearly
alike in staminate and pistillate plants
7A. Spathe-blade saccategaleate; leaflets always 3, filiform at
apex,rather thick, lusterous above, entire A. ringens
7B. Spathe-blade spreading, declined, or ascending anteriorly
8A. Leaflets always 3, with many sub-translucent papillae on
margin; Spathe-blade acuminate A. ternatipartitum
8B. Leaflets 3-15, pedate, margins entire or loosely undulate to toothed;
Spathe-blade radually or abruptly acute
9A. Normal leaves 2, rarely 1 in depauperate individuals (21)
9B. Normal leaf solitary (rarely 2)
10A. Spadix appendage thickened at both ends or at least at the
base, the median and sometimes apical part narrow. 1-2 mm thick; Spathe-blade broadly
deltoid-lanceolate to narrowly deltoid-ovate, 2-3 cm wide; leaflets 7-19 (16)
10B. Spadix-appendage rather stout, 3-10 mm across, terete, or gradually thickened
toward apex; Spathe-blade deltoidovate, 3-5 cm wide
11A. Scape 3-10 cm long, apparently lateral; leaflets somewhat
palmate, without a rachis; Kyushu. A.nanum
11B. Scape 15-50 cm long.
12A. Lateral leaflets 3-8 on each side; rachis, at least the
lower part, well developed (14)
12B. Lateral leaflets 2 (3) on each side, nearly radiate; rachis slightly developed
13A. Spathe-blade obliquely ascending, 5-6 cm long A.
robustum
13B. Spathe-blade strongly declined over the spathe, 8-10 cm long A. ovale
14A. (12) Leaflets obvate, abruptly
short-acuminate; habitat: Izu Peninsula A. izuense
14B. Leaflets lanceolate to oblong-obovate, tapering toward apex; Kinki District
and westward
15A. Spathe-blade oblong-ovate, abruptly long-acuminate,
strongly declined over spadix; spadix-appendage cylindric-clavate, slightly thickened at
apex A. suwoense
15B. Spathe-blade deltoid, abruptly narrowed from top of tubular part, erect, the
apex gradually elongated to a linear tip; spadix-appendage narrowly cylindric terete A.
simense
16A. (10) Spathe entirely green, papillose on
margin A. yoshiokae
16B. Spathe usually purplish, entire
17A. Spathe 3-6 cm long (20)
17B. Spathe-blade 7-10 cm long
18A. Leaflets 9-11; Spathe-blade linear, ovate, gradually
acuminate A. iyoanum
18B. Leaflets 7-9
19A. Spathe-blade ovate-lanceolate, long-acuminate, dark purple
with 4 white stripes; Honshu (Harima Prov.) A. seppikoense
19B. Spathe-blade oblong-lanceolate, subabruptly acute, light purple brown; Aki A.
akiense
20A. (17) Spathe-blade, at least in part,
dark purple, 5-6 cm long, deltoid-lanceolate A. monophyllum
20A. Spathe-blade greenish, ovate, 3-4 cm long A. maximowiczii
21A. (9) Leaflets 3-5; Spathe-blade abruptly
long-acuminate; spadix-appendage capitately thickened at apex A. sikokianum
21B. Leaflets (5-)7-17; spadix-appendage cylindric, slender or cavately thickened
at apex
22A. Spathe-blade acuminate to longacuminate, not
filiform-elongate (24)
22B. Spathe-blade filiform-elongate
23A. Spadix-appendage thick-cylindric; Spathe-blade dark purple
with vertical white stripes A. kishidae
23B. Spadix-appendage clavate, thickened at the apex; Spathe-blade green A.
tosaense
24A. (22) Spathe-blade narrowly to broadly
ovate (27)
24B. Spathe-blade broadly-lanceolate, gradually long-acuminate; spadix-appendage
slenderly cylindric
25A. Spathe-blade bent forward horizontally A.
longilaminum
25B. Spathe-blade declined and arching over the spadix
26A. Spadix-appendage erect A. angustifoliatum
26B. Spadix-appendage slightly bent forward A. shinanoense
27A. (24) Spathe-blade densely yellowish
papillose inside A. yamatense
27B. Spathe-blade smooth inside
28A. Spathe-blade declined above; long acuminate (31)
28B. Spathe-blade obliquely ascending or bent horizontally, abruptly short-acute
29A. Plant loosely tufted with numerous young plants;
Spathe-blade oval to orbicular-ovate A. proliferum
29B. Plant solitary; Spathe-blade ovate
30A. Spadix-appendage thick clavate A. speirophyllum
30B. Spadix-appendage linear or cylindric A. peninsulae
31A. (28) Spathe-blade broadly ovate to
ovate-lanceolate, tapering from below the middle but not from the base (34)
31B. Spathe-blade oblong-deltoid, tapering from base; spadix-appendage cylindric,
the apex as broad as the other part
32A. Spadix-appendage slenderly cylindric or linear (33)
32B. Spadix-appendage cylindric, rather thick, to 8 mm across at the base; tublular
part of the spathe rather long A. solenochlamys
33A. (32) Spadix-appendage linear;
Spathe-blade obliquely declined only at tip; leaflets 9-18, often serrulate; Honshu A.
angustatum
33B. Spadix-appendage cylindric; Spathe-blade declined; leaflets 11-13 in the lower
one, entire; Kyushu A. koshikiense
34A. (31) Leaflets pedate on the
well-developed rachis at least between the lower ones (37)
34B. Leaflets palmate on the scarcely developed rachis; scape longer than the
leaves
35A. Leaflets 5 A. nikkoense
35B. Leaflets more than 5
36A. Leaflets 5-7, not variegated, narrowly oblong, entire or
serrate; spathe auricles very distinct A. stenophyllum
36B. Leaflets 8-14, with a broad white line along the midrib, linear-lanceolate,
always undulate on the margin; spathe auricles narrow and rather inconspicuous A.
undulatifolium
37A. (34) Spathe-blade broadly deltoid-ovate,
the rachis of leaflets spirally curved on the apical part, the auricles almost wanting A.
takedae
37B. Spathe-blade narrower, gradually tapering toward both ends from the middle,
the auricles developed
38A. Auricles of the spathe very broad; Kanto to Oshima in Izu
Provence A. limbatum
38B. Auricles of spathe narrow
39A. Spadix-appendage slightly or scarcely thickened, smooth (41)
39B. Spadix-appendage bulbously thickened at apex, smooth or rugose
40A. Spathe-blade elongate, nearly as long as the tubular part,
spreading nearly at a right angle over the mouth; Kyushu A. mayebarae
40B. Spathe-blade always shorter than the tubular part, strongly declined at the
tip over the mouth; eastern Honshu A. serratum
41A. (39) Tuber globose, not depressed; Isu
Islands A. hachijoense
41B. Tuber depressed-globose; western Honshu A. japonicum
Eric Gouda, Aug.1999
Utrecht University Botanic Gardens Arisaema Page