PRIMARY KEY TO SPECIES OF PEPEROMIA

a. Spikes solitary, or few (2-4) on a common stalk, scarcely paniculate.

b. Leaves scarcely peltate (the margin may join across the petiole in some species).

c. Fruit essentially sessile.

d. Fruit and ovary apically more or less mammiform or stylose; stigmas essentially apical.

e. Leaves alternate, mostly membranous; fruit lacking a pseudo- cupule ........................-.....I. Spp. 1-10 (pp. 77-82)

ee. Leaves mostly 3-4 at a node (sometimes 2); fruit with a pseudocupule II. Spp. 11-19 (pp. 82-87)

dd. Fruit and ovary apically oblique; stigma subapical, anterior. e. Fruit globose-ovoid, short-pointed, subbasally attached ....III. Spp. 20-47 (pp. 88-102)

ee. Fruit ellipsoidal or cylindrical, attached basally, apex obliquely scutelliform or rostrate .IV. Spp. 48-57 (pp. 103-111)

cc. Fruit stipitate .- ................................. V. Sp. 58 (p. 111)

bb. Leaves distinctly peltate .................................-..VI. Spp. 59-66 (pp. 112-116)

aa. Spikes numerous, paniculate ........ ........................ VII. Spp. 67-72 (pp. 117-120)

I. KEY TO SPECIES WITH FRUIT ATTACHED BASALLY, LACKING PSEUDOCUPULE, APICALLY MORE OR LESS MAMMIFORM OR STYLOSE, AND WITH STIGMAS APICAL OR SLIGHTLY SUBAPICAL. (Subgenus TILDENIA Miq. in part).

a. Leaves pinnately nerved or pli-nerved.

b. Margin of floral bracts entire or only slightly irregular.

c. Leaves mostly 15 cm. or more long-...., ..... ............. 1. P. ADSCENDENS

cc. Leaves mostly 10-12 cm. or less long --- .............................................,., 2. P. ACUMINATA bb. Margin of floral bracts ciliate --- 3. P. CILIOLIBRACTEA

aa. Leaves palmately nerved or slightly plinerved near the base only.

b. Leaves and stems glabrous.

c. Leaf apex obtuse; stems short; fruit not longitudinally ribbed.

d. Leaves 5- to 7-nerved; base cordulate ------------------------------ 4. P. BREVIPEDUNCULA

dd. Leaves 9- to 11-nerved; base cordate- ----.5. P. PSEUDO-DEPENDENS

cc. Leaf apex acute; stems erect, branching. d. Midrib obviously branched upward; leaves mostly 1.5-2.5 cm. wide-, ,,,,,,,.. .,,,,..,,,,..,,,,,,,..,,..,. 6. P. PELLUCIDA

dd. Midrib scarcely branched upward; leaves mostly 3 cm. or more wide- ,,.. ,,,,,,,,,,,,,,,,, 7. P. CORDULATIFORMIS

bb. Leaves and petioles hairy.

c. Leaves 3-5 cm. or more long. d. Leaves less than 4 cm. wide; spikes much longer than the leaves-. 8. P. INSUETA

dd. Leaves much wider; spikes shorter than the leaves - - ,- ,,-,,,9. P. UMBRIGAUDENS

cc. Leaves mostly scarcely 1.5 cm. long, mostly hirtellous - ,,,, 10. P. PANAMENSIS

II. KEY TO SPECIES MOSTLY WITH OPPOSITE OR VERTICILLATE LEAVES; FRUIT STYLOSE AND WITH A PSEUDOCUPULE.
(Subgenus MICROPIPER (Miq.) Dahlst.).

a. Leaves scarcely 10-12 mm. long, apex scarcely protracted.

b. Rachis puberulent ........ 11. P. REFLEXA var. AMERICANA

bb. Rachis not puberulent.

c. Stems and leaves glabrous; leaves longer than wide, commonly whorled ............................ 12. P. QUADRIFOLIA

cc. Stems and leaves more or less hairy.

d. Leaves in whorls of 4, round or obovate-elliptic,.,,.......... 13. P. QUATERNATA

dd. Leaves mostly opposite, orbicular........ 14. P. CYCLOPHYLLA

aa. Leaves mostly 10-20 mm. or more long.

b. Leaves about 10-20 mm. long, opposite, apex scarcely narrowed,....... 15. P. QUADRANGULARIS

bb. Leaves mostly much longer, or whorled and constricted toward the apex. c. Stem hirtellous; leaves bluntly constricted-pointed; peduncle 4-5 cm. long ............ 16. P. BOCASENSIS

cc. Stem essentially glabrous, or, if hirtellous, leaves larger, narrowly pointed.

d. Leaf apex minutely hirtellous; leaves drying rather thin, 3 cen-
tral nerves prominent ....... 17. P. MARTAGONIFOLIA

dd. Leaf apex glabrous.

e. Spikes densely flowered, commonly 6-8 cm. long; bracts con-
tiguous or overlapping; leaves drying coriaceous opaque; spikes
often multiple., .... ..................... 18. P. SEEMANNIANA

ee. Spikes loosely flowered, commonly 10 cm. or more long; bracts mostly remote; leaves drying membranous, translucent, spikes mostly solitary............. 19. P. VIRIDISPICA

 III. KEY TO SPECIES WITH GLOBOSE-OVOID, SUBBASALLY ATTACHED FRUIT WITH OBLIQUE SOMEWHAT POINTED APEX AND SUBAPICAL STIGMA.
(Subgenus SPHAEROCARPIDIUM Dahlst.).

a. Leaves opposite or verticillate (lower stem leaves sometimes alternate).

b. Stems minutely velvety hirtellous.

c. Leaves 5 mm. or less wide, 3 times or more longer than wide.

d. Leaves scarcely 2 mm. wide, linear-oblong ...................................-... 20. P. APODA

dd. Leaves 2-5 mm. wide.

e. Leaves spatulate, much longer than wide ................................-.... 21. P. GALTOIDES

ee. Leaves elliptic, scarcely twice longer than wide - -.-....-...-.. 37. P. ALBESCENS

cc. Lcaves wider and proportionately shorter ------------------------------------------.22. P. PALMANA

bb. Stem not hirtellous.

c. Stems glabrous; leaves commonly alternate, subplinerved - .. 23. P. ALLAGOTACTA

cc. Stems more or less hairy.

d. Stems villous, at least toward the base. 

e. Leaves 4-7 mm. wide -----------------------.24. P. BIFRONS

 ee. Leaves 10-20 mm. wide -----------...25. P. VALLICULAE

dd. Stems villous at the nodes only.

e. Leaves mostly 3-4 at a node ------------26. P. BARBINODIS

ee. Leaves 2 or 1 at a node ----------- 27. P. SEIBERTII

aa. Leaves alternate.
b. Rachis conspicuously papillate, plants subcaulescent ----------------------------- 28. P. KILLIPI

bb. Rachis not obviously papillate.

c. Leaves scarcely 1 cm. long, or occasionally up to 2 cm., plants repent.

d. Leaves 2-3 mm. wide, oblong-spatulate --------- 29. P. NIEVECITANA

dd. Leaves mostly wider, rounded, elliptical, or lanceolate.

e. Leaves or some of them 2-3 times longer than wide.

f. Stem essentially glabrous or with only a few scattered
hairs; leaves very variable in shape- 30. P. CHIRIQUIENSIS

ff. Stem evidently hairy.

g. Leaves elliptic-obovate, apex round-emarginate ------------------ 31. P. HYGROPHILOIDES

gg. Leaves narrowly elliptic, apex acute ..................................... 32. P. CHRYSLERI

ee. Leaves mostly scarcely twice as long as wide.

f. Spikes scarcely 5 mm. long ............... 33. P. COCLEANA

ff. Spikes mostly 1-2 cm. or more long.

g. Leaves, or some of them, elliptic or lance-elliptic, sub-
acute.

h. Stems villous ..-...-... 34. P. CRUENTATA

hh. Stems minutely hirtellous ...... 3 5. P. TENUICAULIS

gg. Leaves mostly round, elliptic, or subobovate, obtuse.
h. Plants long-repent, leaves all alternate ..... - .. 36. P. ROTUNDIFOLIA

hh. Plants subcespitose, leaves congested 2-3 together
above . ........................ 37. P. ALBESCENS
cc. Leaves usually much larger.

d. Leaves conspicuously black-dotted.

e. Leaves elliptic-lanceolate, or ovate, mostly broader at or below the middle ........ .38. P. GLABELLA

ee. Leaves elliptic-oblanceolate, mostly wider above the middle.

f. Leaves hairy on both sides; spikes about 15 cm. long -- 39. P. FLAGELLISPICA

ff. Leaves glabrous; spikes shorter .. 40. P. PERCUNEATA

dd. Leaves not obviously black-dotted though sometimes dark-
glandular.

e. Stems glabrous (or somewhat pilose at the nodes only).

f. Inner nerves coalescing within the lowermost 5-10 mm.;
leaves more or less elliptic-oblanceolate.

g. Spikes 3 cm. or more long ............... 41. P. DIRUPTORUM

gg. Spikes 1 cm. long; peduncle equilong . ..... 23. P. ALLAGOTACTA

ff. Nerves not obviously coalescent.

g. Leaves 2.3-4.5 cm. wide.

h. Plants ascending scarcely 20 cm.; leaves abruptly and
bluntly short-acuminate, nervules by transmitted light
numerous and anastomosing .42. P. PASCUICOLA

hh. Plants to 1 m. tall; leaves, at least above, narrowly
attenuately sharp-acuminate, nervules not conspicuous-
ly numerous or strongly anastomosing ............ 43. P. ELATA

gg. Leaves mostly 2 cm. or less wide.

i. Leaves less than twice as long as wide ......................... 44. P. LEUCOSTICTA

ii. Leaves 2-3 times longer than wide.

j. Nodes more or less pilose; upper leaves opposite... 27. P. SEIBERTII

jj. Nodes glabrous; upper leaves alternate ................. 45. P. PARIETARIAEFOLIA

ee. Stems hairy.

f. Leaves mostly less than 2 cm. wide.

g. Plants ascending 10-15 cm.; stems villous upward - 46. P. OBSCURIFOLIA

gg. Plants ascending to 30 cm. or more; stems villous
downward, glabrescent above ................. 25. P. VALLICULAE

ff. Leaves mostly 2-3.5 cm. wide, obtuse .................................... 47. P. DAVIDSONII

IV. KEY TO SPECIES WITH CYLINDRICAL OR ELLIPSOIDAL, BASALLY ATTACHED FRUIT, AND WITH APEX OBLIQUELY SCUTELLIFORM AND STIGMA MORE OR LESS CENTRAL, OR SLENDERLY ROSTRATE, AND STIGMA ANTERIOR NEAR THE BASE
OF THE BEAK. (Subgenus RYNCHOPHORUM (Miq.) Dahlst. in part). 

a. Fruit mostly more or less cylindrical, sometimes thicker downward, apex obliquely scutelliform. 

b. Leaves subpeltate ........... 61. P. CORDULATA 

bb. Leaves not at all peltate. 

c. Plants conspicuously black-dotted ....................................................... 3 8. P. GLABELLA 

cc. Plants not black-dotted, glands, if present, not black. 

d. Petioles mostly less than 5 mm. long, stout.
e. Stems and leaves glabrous ....... 48. P. PORTOBELLENSIS 

ee. Stems and/or petioles villous when young and/or about the
nodes, leaves mostly drying more or less coriaceous and opaque.. 49. P. CAUDULILIMBA 

dd. Petioles mostly 5-20 mm. long, not markedly stout, leaves
mostly drying membranous and translucent. 

e. Petioles and/or young stems, if hairy, minutely hirtellous ...... 50. P. OBLONGIBACCA 

ee. Petioles somewhat villous-ciliate, stems glabrous or the nodes sparsely villous ........... 50c. P. OBLONGIBACCA
var. SUBVILLOSA 

aa. Fruit mostly ellipsoidal, apex more or less slenderly rostrate, stigma anterior. 

b. Leaves palmately nerved, or essentially so. 

c. Leaves mostly 1-2 cm. long, as wide as long, apex scarcely protracted .................................. 51. P. SERPENS 

cc. Leaves mostly larger. 

d. Spikes on axillary stalks ............... 52. P. UROCARPOIDES 

dd. Spikes on leaf-opposed stalks. 

e. Leaves narrowly peltate, strongly red-glandular ........................ 65. P. PERGLANDULOSA 

ee. Leaves not peltate nor strongly red-glandular ............................ 53. P. DIGITINERVIA 

bb. Leaves pli- or pinnately-nerved. 

c. Leaves elliptic-ovate, base rounded .... 54. P. DISTACHYA 

cc. Leaves not ovate, base mostly acute to cuneate. 

d. Leaves puberulent above, scarcely more than 5 cm. long -------------- 55. P. MACHAERODONTA 

dd. Leaves glabrous, or obscurely hirtellous along the midrib beneath, mostly larger.

e. Peduncle minutely hirtellous. 

f. Bracts strongly imbricated ................................................ 5 6b. P. OBTUSIFOLIA var. LONGIBRACTEATA 

ff. Bracts scarcely imbricated, mostly 0.3-0.4 mm. wide; fruit
beak slender, terete, strongly hooked ........................................- 56. P. OBTUSIFOLIA 

ee. Peduncle glabrous, bracts mostly 0.5 mm. wide; fruit beak
gradually narrowed from a wide base, not strongly hooked ...... 57. P. MAGNOLIAEFOLIA

VI. KEY TO SPECIES WITH PELTATE LEAVES 

a. Fruit scarcely rostrate, apex acute, mammiform, or obliquely scutelliform. 

b. Stems very short, scarcely 1 cm. long; rachis strongly hispidulous - 59. P. HISPIDORHACHIS 

bb. Stems much longer. 

c. Leaves pubescent beneath; petioles more than half as long as the blade, slender - -.--. --..----60. P. CERRO-PUNTANA 

cc. Leaves glabrous; petioles shorter, stout - 61. P. CORDULATA 

aa. Fruit rostrate. 

b. Petiole attached 1-2 cm. or more from the leaf margin. 

c. Main lateral nerves conspicuous and strongly curved toward the apex -.-----------------------------62. P. FLEXINERVIA 

cc. Main lateral nerves rather obscure and ascending more sharply. 

d. Leaves mostly 6-8 cm. wide - 63. P. CILIIFERA 

dd. Leaves mostly 5 cm. or less wide - 64. P. CONSERTA 

bb. Petiole attached within 1 cm. of the margin. 

c. Leaves 10 cm. or more long ----------------------------------- 65. P. MACULOSA 

cc. Leaves 3 cm. or less long -.--66. P. PERGLANDULOSA

VII. KEY TO SPECIES WITH NUMEROUS SPIKES ARRANGED IN A COMPOUND, PANICULATE INFLORESCENCE.
(Subgenus PANICULARIA Miq.).

a. Spikes scarcely more than 1 cm. long; fruit subcylindrical with oblique apex; inflorescence stalk microscopically hirtellous .................................... 67. P. PERNAMBUCENSIS

aa. Spikes mostly 3 cm. or more long; fruit not as above.

b. Leaves sessile or ubsessile ..... 68. P. DURICAULIS

bb. Leaves obviously petiolate.

c. Spikes mostly less than 10 in each panicle.

d. Leaves obovate, mostly 10 cm. or more wide . ....................... 69. P. WILLIAMSII

dd. Leaves elliptic-oblanceolate, scarcely 5 cm. wide.
e. Stems, leaves, etc. villous ........... 70. P. WEDELII

ee. Stems glabrous ............ 56b. P. OBTUSIFOLIA var.
LONGIBRACTEATA

cc. Spikes mostly 12 or more in each panicle; leaves elliptic, elliptic-oblong, or oblanceolate, mostly 6-8 cm. wide.
d. Leaves glabrous; stem only a few cm. long, scarcely erect .., 71. P. MAMEIANA

dd. Leaves pubescent, at least beneath.

e. Plants rhizomatous; leaves villous along the nerves beneath,
glabrous above ................................. 70. P. WEDELII

ee. Plants with erect stems up to 100 cm. tall; leaves silky-ap-
pressed-villous on both sides . . .......72. P. SUBSTRIATA