Key F

Leaves simple, not lobed; blades neither cordate nor subcordate at base, epunctate.

1a. Geniculum situated at least 7 cm below the base of the blade; plants terrestrial...... A. oerstedianum Schott

2a. Plants scandent, the stem elongate, with long internodes, the leaves dispersed throughout much of the length of the stem. If not

3a. Spathe decurrent on the peduncle (0.5)1-1.5 cm; berries yellow to orange or white......... A. pittieri Engl.

3b. Spathe essentially not decurrent; berries green, yellow, orange or bright red to red-violet.

4a. Stem with two or more successive, abbreviated internodes alternating with greatly elongated internodes, 8-33 cm long; leaves drying brownish-green or olive-green; berries bright red or purple-red; below 1,000 m........... A. interruptum Sodiro

4b. Stem with internodes nearly uniform length, decreasing slightly toward the apex of the stem; leaves drying dark brown to blackish or pale green; berries green, red or orange; usually above 1,200 m elevation, rarely below 1,000 m.

5a. Petioles less than 3 cm long; peduncles less than 4 cm long, enclosed at base in an elongate leaf sheath....... A. tenerum Engl.

5b. Petioles more than 3 cm long, peduncles more than 5 cm long.

6a. Blades drying black or blue-black, dark brown on the upper surface, medium brown on the lower surface; leaves fleshy when fresh; veins obscure; 1,500-2,600 m...... A. carnosum Croat & Baker

6b. Blades drying dark green to pale green above, pale yellow-green or occasionally brownish beneath; leaves thickly chartaceous; veins prominent below; 700-2,300 m. 6'a. Spadix more than 7 cm long at anthesis, slender and narrowly tapered to apex; berries red, early emergent, oblong. ...................... A. testaceum Croat <&. Baker

6b. Spadix less than 5 cm long at anthesis, blunt and scarcely tapered to apex; berries yellow-green, not early emergent, more or less globose.

7a. Petioles mostly more than 15 cm long; leaf base acute to rounded; stipe 1-5 mm long; leaves usually clustered at the ends of branches (internodes short) with the more elongate lower nodes usually leafless.................... A. pallens Schott

7b. Petioles mostly less than 15 cm long; leaf base often truncate or subcordate; stipe 2-10 mm long; leaves evenly distributed along the branches and persistent, the apical internodes not usually shortened. .......A. microspadix Schott

8a. Petioles terete or subterete, never quadrangular, rectangular, or triangular, often narrowly or broadly sulcate on upper side with the margins sharp or blunt but merely rounded on lower side, never prominently ribbed on lower side.

9a. Major lateral veins mostly free to the margins, sometimes weakly loop-connected in apical half of blade, never with a conspicuous, almost straight collective vein arising from near the base.

10a. Peduncle usually shorter than petiole, never more than two times longer than petiole; spadix usually more or less oblong, usually short and thick, never long, linear-tapered; peduncle less than twice as long as spadix; berries red. ................. A. cubense Engl.

10b. Peduncle mostly two or more times longer than petiole; spadix usually elongate, cylindroid-tapered, never oblong (except A. consobrinum), if short then not thick; peduncle more than twice as long as spadix; berries red, white, cream, greenish, orange or yellow, not violet-purple.

11a. Pistils acutely pointed at apex; berries white, cream, yellow, orange, sometimes white tipped with orange, yellow or reddish at apex only; species of the Atlantic slope.

12a. Mature spadix cylindroid, not tapered, to ca. 9 cm long and 1.5 cm (including pistils) diam. at anthesis, the pistils exserted well above the stamens and emerging weeks ahead of the stamens; berries white at base, reddish at apex; midrib rounded on lower leaf surface near the base of the blade.................... A. consobrinum Schott

12b. Mature spadix cylindroid-tapered, 12-15 cm long and ca. 8 mm diam. At base at anthesis, the pistils not apparent before anthesis, obscured by the stamens when stamens are exserted; berries white, cream, yellowish, or orange, usually a solid color throughout; midrib usually more or less trapezoidal with two sharp ribs on the lower leaf surface near the base of the blade. ................................................................................................................. A. fatoense K. Krause

11b. Pistils not emerging early, rounded at apex; berries greenish-white or red, usually blunt at apex; roots 3 mm or more thick, free-ending or not but not all uniformly turned upward, not conspicuously acute at apex.

13a. Spathe ovate, pale green, erect, and enshrining the spadix; spadix pale È green, moderately stubby, usually less than 6.5 cm long; plants usually terrestrial or on soil deposits on rocks; blades usually elliptic; roots mostly 1 cm diam. when fresh; eastern Guatemala and western El Salvador on the Pacific slope................. A. salvadorense Croat

13b. Spathe lanceolate (except A. halmoorei), usually green to violet-purple, reflexed or spreading; spadix green to pale lavender or purplish, usually rather slender and long-tapered, usually more than 6.5 cm long; plants usually epiphytic or epipetric (except A. nizandense), blades usually oblanceolate-elliptic to oblanceolate (except sometimes elliptic on A. nizandense), roots mostly less than 6 mm diam. When fresh; Mexico to Colombia.

14a. Leaf blades obovate-elliptic, 1.3-2.5 times longer than petioles, less than 3 times longer than broad; Mexico in southern Oaxaca and Guerrero A. nizandense Matuda

14b. Leaf blades generally oblanceolate or oblanceolate-elliplic, 3 or more times longer than petioles; usually 3 or more times longer than broad.

15a. Spathe ovate to broadly ovate; berries pale greenish-yellow; western Mexico in Nayarit, Jalisco, Colima, and Michoacan.......................... A. halmoorei Croat

16a. Cataphylls cucullate (hooded), fist-shaped before opening; inflorescence frequently pendent at anthesis; spadix usually long-tapered, pale lavender, weakly È. glaucous; spathe long and narrowly tapered to apex, spreading, thin, almost as long as the spadix; Pacific slope except from Nicaragua to Panama. .......................................................A. salviniae Hemsl.

16b. Cataphylls lanceolate; inflorescence usually erect; spadix short-tapered, green to violet-purple, not glaucous; spathe moderately short, reflexed, coriaceous, usually much shorter than spadix.

17a. Plants occurring on rocky, dry slopes; Pacific slope of Mexico in Guerrero and southern Oaxaca. .......... A. schlechtendalii ssp. jimenezii (Matuda) Croat

9b. Major lateral veins mostly joining into a straight or conspicuously loop-connected collective vein, this arising usually in the lower half of the blade; plants with or without the rosulate habit.

18a. Spadix with no more than two to five flowers exposed across its diameter in any spiral from any angle of view.

19a. Leaf blades broadest above the middle, tapered to a long cuneate base; spathe red-violet; spadix purple-brown; berries red; roots usually white................. A. gracile (Rudge) Lindl.

19b. Leaf blades broadest at or below the middle, acute to rounded at base; spathe green; spadix green, yellow or orange, sometimes tinged purple; berry color various.

20a. Spathe decurrent onto peduncle (0.5)1-1.5 cm; pistils early emergent many times longer than stamens at anthesis; berries yellow or orange. ........ A. pittieri Engl. ssp. pittieri

20b. Spathe not long-decurrent onto peduncle; pistils scarcely longer than stamens at anthesis; berries green or red (not known in A. pittieri var. fogdenii but probably orange).

21a. Spathe to 7 cm long; spadix 4-12 cm long; berries red........................... A. testaceum Croat & Baker

21b. Spathe less than 3.5 cm long; spadix less than 4.5 cm long; berries greenish (A. pallens) or probably orange (A. pittieri var. fogdenii).

22a. Leaf blades less than 10 cm long, thick, veins shallowly etched above, obscure below; primary lateral veins three to four per side.......... A. pittieri var. fogdenii Croat

22b. Leaf blades more than 15 cm long, moderately thin, tertiary veins prominulous below (dry), primary lateral veins five to nine per side................ A. pallens Schott

23a. Petioles mostly less than 10 cm long; blades usually six or more times longer than petioles.

24a. Collective vein arising from one of the primary lateral veins, well above the base; berries white at base, reddish or purplish at apex; pistils early long-exserted, much longer than the stamens. ................. A. consobrinum Schott

25a. Spadix stubby, creamy-white; spathe lanceolate-ovate, clasping at the base; cataphylls thick, persisting intact; Costa Rica on the Pacific slope. ....................... A. eximium Engl.

25b. Spadix slender and long-tapered, greenish; spathe lanceolate, acute or obtuse at the base; cataphylls thin, weathering into fibers; Mexico in Oaxaca............... A. machetioides Matuda

23b. Petioles usually 11 cm or longer; blades no more than four times longer than petioles.

27a. Leaf blades lacking any obvious basal veins, the lowermost primary lateral veins more or less equal or less prominent than those higher up on the blade. ' 28a. Tertiary and higher order veins conspicuously elevated (at least when dry)......... A. retiferum Standl. & Steyerm.

28b. Tertiary and higher order veins obscure, much less prominent than the primary lateral veins... A. parvispathum Hemsl. ,

29b. Collective vein arising from the uppermost basal vein or even from one of the primary lateral veins; primary lateral veins usually conspicuously more prominent than the interprimary or tertiary veins; blade usually not conspicuously broadened at the base (sometimes so in A. nakamurae). 30a. Blades broadest near or even above the middle, six or more times longer than broad; southwestern Chiapas. A. nakamurae Matuda

31 b. Major veins of lower blade surface green; Guatemala to Honduras. ..... A. subcordatum Schott

32a. Major lateral veins obscure (prominulous when dry but scarcely more prominent than the tertiary venation); the midrib reddish in lower half of blade (less noticeable after drying); cataphylls not dilacerating, soon deciduous. ........................................ A. burgeri Croat & Baker

32b. Major lateral veins prominent, much more conspicuous than the tertiary veins; midrib not reddish; cataphylls usually dilacerating at least at base, usually persisting for a considerable time. 33a. Cataphylls less than 15 cm long and less than 1 cm wide at the middle, weathering into mostly longitudinal fibers; stem mostly ca. 1 cm diam., elongate, with many white to tan roots among the existing leaves; inflorescences usually erect at anthesis, arching in fruit; spadix usually less than 6 mm diam. At base, berries pale green. .................................... A. angustispadix Croat & Baker

33b. Cataphylls more than 15 cm long or more than 1.5 cm wide at the middle, often weathering into a net-like structure (with coarse longitudinal fibers underlain by finer, diagonally directed fibers), or remaining intact near apex; stem mostly 2 cm diam. Or more, usually lacking white to tan roots among the existing leaves; inflorescences usually spreading to pendent at anthesis, pendent in fruit (except A. cuspidatum); spadix mostly more than 7 mm diam. At base (except A. protensum and A. cuspidatum); berries not pale green.

34a. Leaf blades ovate to oblong-ovate, mostly more than 20 cm wide, truncate to subcordate at base, the basal veins united into a short trunk vein............. A. cuspidatum Mast.

34b. Leaf blades oblong to oblong-elliptic, mostly less than 20 cm wide, acute to attenuate or subrounded at base, lacking a posterior rib.

35a. Spathe and spadix less than 8.5 cm long; spathe ovate, cordate at base, ca. half as wide as long. ......................................................................... A. brenesii Croat & Baker

35b. Spathe and spadix more than 10 cm long; spathe lanceolate to linear, not cordate, much more than twice as long as wide. 36a. Leaves much paler and whitish beneath; spadix yellow-green; rosulate plant with erect-spreading leaves; blades to 54 cm long. ................................................ A. Michelii Guillaumin

37a. Spadix 30-75 times longer than wide, to ca. 60 cm long, the fruiting spadix more than 30 cm long; flowers more than 1.8 mm wide (dry) at apex; plants occurring below 600 m. .................... A. prolatum Croat & Baker

37b. Spadix less than 20 times longer than wide at anthesis, to 20 cm long, the fruiting spadix usually less than 25 cm long; apex of flowers less than 1.5 mm wide; plants occurring above 900 m.............. A. protensum Schott

8b. Petioles quadrangular, rectangular, decidedly triangular or prominently 1- or more ribbed on lower (abaxial) side.

39a. Stem usually 1-1.5 cm diam., comparatively elongate, at least the lower internodes not completely obscured by the roots; inflorescencesÈ usually arched-spreading; infructescence pendent, the spadix greenish to white or pale reddish to pale purple.

40a. Leaf blades thickly chartaceous; berries cream to pale orange or yellow; roots many, compact, more or less contiguous, tapering, slender, ascending; petioles mostly less than 10 cm long................. A.fatoense K. Krause

40b. Leaf blades subcoriaceous; berries red; roots moderately dense, thick, blunt, not ascending; petioles mostly more than 10 cm long............ A. upalaense Croat & Baker

39b. Stem usually more than 2.5 cm diam. (At least on mature individuals), the internodes mostly completely obscured by the roots, the roots moderately stout, usually more than 3 mm diam., not all elongate tapered and regularly directed upwards; inflorescence erect or spreading; infructescence erect or pendent; spadix dark violet-purple or green or green tinged purplish.

4 1a. Species occurring from Mexico to El Salvador, frequently on rocks; berries red or pale greenish-yellow or greenish-white.

42a. Leaf blades obovate-elliptic, less than three times longer than broad, 1.3-2.5 times longer than petioles; southern Oaxaca and Guerrero ..... A. nizandense Matuda

44b. Spathe reflexed; berries pale greenish-yellow; petiole obtusely 3-sided; western Mexico in Nayarit, Jalisco, Colima, and Michoacan...................... A. halmoorei Croat

45a. Plants from the Pacific slope in Guerrero and Oaxaca; dry rocky slopes. ...... A. schlechtendalii ssp. jimenezii (Matuda) Croat

4 1B. Species of Costa Rica and Panama to as far north as Nicaragua.

46a. Peduncles usually shorter than petioles, rarely to 1.5 times longer than petioles; petioles usually sharply quadrangular, flat or 3-ribbed on lower side (abaxial), the sides unribbed; spathe purplish; spadix often short, 5-22 cm long; pistils emerging early; berries red, acute at apex............................ A. purpureospathum Croat

46b. Peduncles usually 1.5-3 times longer than petioles; petioles subquadrangular, lacking abaxial ribs; spathe 16-17 cm long, green; spadix 15-23 cm long; pistils not emerging early; berries orange, flattened at apex. ........................... A. validifolium K. Krause

spathe broadly ovate or narrowly ovate; berries greenish to white or red.

48a. Spadix usually clavate or subclavate; cataphylls soon weathering to longitudinal, persistent, pale fibers; spathe cucullate, ovate; berries greenish; plants of the Atlantic slope from 0-650 m. È

49a. Blades with 20-30 pairs of primary lateral veins, these prominently sunken; spathe lanceolate to broadly lanceolate, about twice as long as the spadix; petiole commonly triangular, 3-5-ribbed........ A. spathiphyllum N. E. Brown

49b. Blades with (5)10-15 pairs of primary lateral veins, these weakly sunken; spathe ovate, about as long as the spadix; petiole commonly quadrangular............ A. cuneatissimum (Engl.) Croat

47b. Spadix usually conspicuously tapered toward the apex; spathe narrowly ovate to lanceolate or oblong-lanceolate; berries greenish, violet-purple, orange or red.

50a. Petioles triangular, acutely 1 -ribbed on lower (abaxial) side; blades markedly bicolorous, the lower surface creamy-green, drying black to olive-brown, lower surface with the major veins conspicuously darker than the surface, scarcely or not at all raised, the tertiary veins obscure; berries bright violet-purple, acute at apex. ....................................................... A. michelii Guillaumin

51 a. Plants terrestrial; blades attenuate at base (broadly concave between lower third of blade and geniculum); berries greenish-yellow........................................ A. acutifolium Engl.

51b. Plants epiphytic; blades acute to truncate or rounded at base; berries orange or red.

53a. Peduncles usually greatly exceeding petioles when fully mature; blades usually less than 16 cm wide; spadix usually less than 20 cm long at anthesis; stamens held just above tepals, the filaments usually not visible; anthers ca. 0.5 mm long.......................................................................... A. seibertii Croat & Baker

5 3b. Peduncles usually shorter than petioles; blades usually more than 20 cm wide; spadix usually more than 20 cm long at anthesis; stamens prominently exserted above the tepals, the filaments exposed; anthers ca. 0.9 mm long.................................. A. spectabile Schott