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L161 H41
ORCHIDS OF PERU
Photograph by Louis O. Williams
CHARLES SCHWEINFURTH
FIELDIANA: BOTANY
A Continuation of the
BOTANICAL SERIES
of
FIELD MUSEUM OF NATURAL HISTORY
VOLUME 30
CHICAGO, U.S.A.
1958-1961
Library of Congress Catalog Card Number: 58-10546
PRINTED IN THE UNITED STATES OF AMERICA
BY CHICAGO NATURAL HISTORY MUSEUM PRESS
ORCHIDS OF PERU
CHARLES SCHWEINFURTH
7*
era
,/FIELDIANA: BOTANY
VOLUME 30, NUMBER 2
Published by
CHICAGO NATURAL HISTORY MUSEUM
MARCH 27, 1959
RIOLOG'l
VARGASIELIA
s
Vargosiella peruviana C. Schweinf. 1, plants; X % 2, flower, from side;
X 1 1 A. 3, dorsal sepal; X 2. 4, petal; X 2. 5, lip, expanded, from above; X 2.
6, column and lip, from side; X 2. 7, anther with pollinia, from below; X 8.
ORCHIDS OF PERU
ORCHIDS OF PERU
CHARLES SCHWEINFURTH
Research Fellow, Ames Orchid Herbarium
Botanical Museum of Harvard University
FIELDIANA: BOTANY
VOLUME 30, NUMBER 2
Published by
CHICAGO NATURAL HISTORY MUSEUM
MARCH 27, 1959
Library of Congress Catalog Card Number: 58-105^6
PRINTED IN THE UNITED STATES OF AMERICA
BY CHICAGO NATURAL HISTORY MUSEUM PRESS
CONTENTS
Genera Included in Volume 30, Number 2
Pleurothallis 261 Liparis 373
Lepanthopsis 358 Diothonea 380
Brachionidium 360 Amblostoma 384
Octomeria 361 Hexisea 387
Vargasiella 367 Lanium 388
Malaxis .
367 Epidendrum 390
LIST OF ILLUSTRATIONS
Vargasiella perurviana Frontispiece
TEXT FIGURES
PAGE
46. Pleurothallis angustipetala 273
47. Pleurothallis carinata 278
48. Pleurothallis carnosifolia 280
49. Pleurothallis crateriformis 289
50. Pleurothallis cyathiflora 291
51. Pleurothallis echinocarpa, P. brevispicata 299
52. Pleurothallis excisa 300
53. Pleurothallis remotiflora 303
54. Pleurothallis graciliscapa 308
55. Pleurothallis hirsutissima 311
56. Pleurothallis inaequisepala, P. tenuis 313
57. Pleurothallis longiserpens 317
58. Pleurothallis magnipetala 319
59. Pleurothallis pantasmoides 323
60. Pleurothallis quadrata, P. dilatata 329
61. Pleurothallis retusiloba 331
62. Pleurothallis ringens 334
63. Pleurothallis ruscifolia 337
64. Pleurothallis spathulifolia, P. caudatipetala 343
65. Pleurothallis Talpinaria 345
66. Pleurothallis tenuifolia 347
67. Pleurothallis Vargasii 355
68. Lepanthopsis floripecten 359
69. Octomeria complanata 363
70. Octomeria semiconnata 366
71. Liparis elata 375
72. Liparis laticuneata 378
73. Diothonea exasperata 382
74. Amblostoma gracile var. robustum 386
75. Epidendrum ampliracemum 407
PAGE
76. Epidendrum aquaticoides 409
77. Epidendrum birostratum 414
78. Epidendrum breviracemum 417
79. Epidendrum capitellatum 418
80. Epidendrum carnosiflorum, E. latisegmentum 420
81. Epidendrum ciliare 423
82. Epidendrum crassum 428
83. Epidendrum difforme 436
84. Epidendrum elatum 438
85. Epidendrum laceratum 462
86. Epidendrum Macbridei, E. liguliferum 465
87. Epidendrum magnicallosum, E. subreniforme 470
88. Epidendrum minutidentatum, E. orbiculatum 475
89. Epidendrum minutiflorum, E. nanum . 477
90. Epidendrum nocturnum 482
91. Epidendrum pilosum 494
92. Epidendrum pubiflorum 497
93. Epidendrum pygmaeum 499
94. Epidendrum rectopedunculatum 501
95. Epidendrum reflexilobum 503
96. Epidendrum refractoides 503
97. Epidendrum rigidum 506
98. Epidendrum Schlechterianum 511
99. Epidendrum strictiforme 517
100. Epidendrum strobiliferum 518
101. Epidendrum subliberum 520
102. Epidendrum tenuispathum 522
Orchids of Peru
PLEUROTHALLIS R. Br. (Humboldtia Ruiz and Pav. in part)
A large and variable genus of American orchids which are commonly epiphytic;
according to some recent researches, the genus includes Restrepia and Barbosella.
Primary stems long-creeping or abbreviated. Secondary stems not pseudo-
bulbous, distant or crowded, minute to elongate, simple and apically 1-leaved or
branched (superposed), very rarely leafy, more or less concealed by tubular sheaths
which sometimes terminate in a flaring, hispid mouth. Leaves orbicular to
linear (often cordate) or terete, short or elongate. Inflorescences axillary, 1 to
numerous, 1- to many-flowered and racemose. Flowers minute to relatively
large. Dorsal sepal free or very shortly connate with the lateral sepals at the
base. Lateral sepals entirely connate to free. Petals commonly much smaller
than the sepals, longer than broad. Lip about equaling the petals or smaller,
simple to several-lobed. Column abbreviated to elongate, often winged above,
with a more or less distinct foot. Pollinia either 2 or 4.
Al . Cauline sheaths lepanthif orm, i.e., tubular with a spreading, hispid mouth . I
A2. Cauline sheaths not lepanthif orm, i.e., without spreading, hispid mouth. . .8
la. Sepals ciliate or scabrous on the margin 1
Ib. Sepals smooth on the margin; lip lightly 3-lobed or simple 2
la. Leaves oval or broadly oblong, rounded and emarginate at the tip; sepals
narrowed to a long, subulate apex; lip 3-lobed near the base.
P. chamaelepanthes
Ib Leaves linear-elliptic to elliptic, obtuse to acute; sepals acute to subacute;
lip simple ....P.tiliaris
2a. Dorsal sepal not linear, acute or short-acuminate 3
2b. Dorsal sepal linear or abruptly long-acuminate or caudate above 4
3a Inflorescences much surpassing the leaf; petals narrowly oblanceolate.
P. dura
3b. Inflorescences subequaling the leaf ; petals oblong-obovate ... P. brevispicata
4a Leaf much longer than the inflorescences; lip little longer than broad.
P. inaequisepala
4b. Leaf much shorter than the inflorescences; lip much longer than broad. . 5
5a Petals rounded above; pedicels only about twice as long as the floral bracts.
P. arbuscula
5b. Petals acute, acuminate or caudate; pedicels much surpassing the minute
floral bracts
6a Lip simple; petals minutely denticulate; stems superposed or branched.
P. dinotherii (P. diptera, P. tricaudata)
6b. Lip lightly but distinctly 3-lobed near the base; petals entire 7
261
262 FIELDIANA: BOTANY, VOLUME 30
7a. Stems simple, short (up to 4 cm. long), 1-leafed at the summit; leaves
commonly 2 cm. or more long P. tennis
7b. Stems commonly branched or superposed, more or less leafy; leaves 1.8
cm. or less long P. amygdalodora
8a. Ovary densely long-hirsute or densely muricate 9
8b. Ovary glabrous or short-pubescent 12
9a. Entire plant (including the outer surface of the sepals) densely long-hirsute;
inflorescences abbreviated, 1-flowered, fasciculate P. hirsutissima
9b. Entire plant glabrous; inflorescences more or less elongate, racemose, with
the floral bracts conspicuous, spreading, dorsally carinate 10
lOa. Lip with a pair of prominent falcate-lanceolate lobes near the base, lamina
distinctly bicallose; petals with a pedicellate tubercle near the base in
front P. gigantea
lOb. Lip without a pair of prominent falcate-lanceolate lobes, lamina not dis-
tinctly bicallose; petals without a pedicellate tubercle at the base 11
lla. Petals decurrent on the column and often obliquely round-auriculate on
one or each side at the base; lip with a narrow, acute or obtuse apex.
P. muricata (P. sororia, P. rufescens)
lib. Petals not decurrent on the column, with a minute tooth on each side at
the base; lip with a broad, denticulate apex P. echinocarpa
12a. Secondary stems abbreviated or short and indistinct 13
12b. Secondary stems more or less elongate, commonly about one third as long
as the leaf or more 26
13a. Petals long-ciliate; plant small, caespitose P. macroblepharis
13b. Petals not long-ciliate 14
14a. Sepals with a broad dorsal keel throughout P. trialala
14b. Sepals, at least the dorsal one, without a broad keel throughout 15
15a. Lip pandurate, i.e., distinctly and sharply narrowed in the middle of each
side 16
15b. Lip not pandurate 18
16a. Petals abruptly caudate; plant caespitose, very small P. caudatipetala
16b. Petals not caudate, rounded to retuse above; plants with a creeping rhi-
zome 17
17a. Sepals not caudate; flowers very small; margins of the lip entire. .P. dedivis
17b. Sepals long-caudate; flowers relatively large; margins of the anterior half
of the lip fimbriate P. longiserpens
18a. Plant with a prominent, long-creeping rhizome 19
18b. Plant caespitose, with an abbreviated or shortly creeping rhizome 20
19a. Inflorescence shorter than or subequaling the leaf, commonly several-
flowered; petals cuneate to spatulate P. macrorhiza (P. rhizomatosa)
19b. Inflorescence much exceeding the leaf, always 1-flowered; petals gradually
linear-attenuate P. rhynchantha
20a. Column abbreviated; lip long-narrowed and acuminate 21
20b. Column more or less elongate; lip acute to rounded at the apex 22
21a. Plant very small, leaves 1 to rarely 3.5 cm. long and 4 mm. or less wide;
petals linear-lanceolate.
P. lancilabris var. oxyglossa (P. oxyglossa, P. Schulzeana)
21b. Plant medium-sized, leaves 4 cm. or more long and 10 mm. wide; petals
ovate-lanceolate . . . P. misera
SCHWEINFURTH: ORCHIDS OF PERU 263
22a. Rachis of the inflorescence abbreviated; inflorescences 1-flowered or sub-
umbellate; lip rhombic P. parvifolia
22b. Rachis of the inflorescence elongate; inflorescences racemose; lip not
rhombic 23
23a. Sepals densely villous within; petals broadly cuneate-spatulate to lunate-
semiorbicular from a slender claw P. flexuosa (P. remotiflora)
23b. Sepals glabrous within; petals not broadly cuneate to lunate-semiorbicular
nor clawed 24
24a. Sepals linear, free, about 1.5 cm. or more long; petals linear or linear-
lanceolate, minutely ciliate P. attenuata
24b. Sepals ovate to lanceolate, the lateral ones more or less connate, about
1 cm. or less long; petals not linear 25
25a. Petals oblong-oblanceolate; lip oblong, about the same width throughout.
P. Grobyi (P. picta)
25b. Petals elliptic-lanceolate; lip ovate-oblong, widest near the base.
P. spathulifolia
26a. Stems provided with several distichous leaves. .P. caulescens (P. graminea)
26b. Stems 1-leafed at the summit; if branching, 1-leafed at the apex of each
stem-member 27
27a. Inflorescences 1-flowered, often clustered 28
27b. Inflorescences several- to many-flowered 56
28a. Leaf abruptly rounded or cordate at the base, sessile 29
28b. Leaf narrowed below, or if rounded at the base provided with a distinct
petiole 42
29a. Petals relatively large, oblong-lanceolate or linear-elliptic, nearly straight
and subentire; leaves often sharply reflexed; plant small. . .P. magnipetala
29b. Petals relatively small, subulate, linear to linear-oblanceolate or triangular-
lanceolate (if oblong-lanceolate, strongly falcate and denticulate) 30
30a. Margin of the petals entire 31
30b. Margin of the petals denticulate to pubescent 35
3 la. Dorsal sepal much broader than the lamina of the united lateral sepals;
lip deeply concave-saccate P. crateriformis
31b. Dorsal sepal more or less narrower than the lamina of the united lateral
sepals 32
32a. Flowers large; sepals 9 mm. or more long 33
32b. Flowers small; sepals 6 mm. or less long 34
33a. Lip elliptic-lanceolate in outline, constricted near the base; leaf deeply
cordate at the base P. chanchamayoensis
33b. Lip suborbicular-ovate, without a basal constriction; leaf lightly cordate
or rounded at the base P. ruberrima
34a. Margins of the lip prominently thickened, lamina elliptic-oblong, acute;
petals triangular-linear with a distinctly broadened base; leaf broadly ovate.
P. syringifolia
34b. Margins of the lip not conspicuously thickened; petals not distinctly
broadened at the base; leaf usually oblong-ovate P. tridentata
35a. Petals narrowly lanceolate or oblong-lanceolate, strongly falcate-incurved.
P. cordata (P. brachyblephara)
35b. Petals subulate to narrowly linear or linear-lanceolate 36
264 FIELDIANA: BOTANY, VOLUME 30
36a. Sepals pubescent; lip broadly obtuse to rounded at the apex; flowers rela-
tively large P. grandiflora
36b. Sepals glabrous; lip obtuse to abruptly acute or apiculate; flowers com-
monly small 37
37a. Rhizome creeping, prominent P. undulata
37b. Rhizome abbreviated, plant caespitose 38
38a. Leaves rounded to shallowly cordate at the base, relatively narrow,
oblong-linear, lanceolate or ovate-oblong to elliptic-oblong 39
38b. Leaves more or less deeply cordate at the base, broadly ovate or lanceo-
late-ovate 41
39a. Lip with a conspicuous narrow claw at the base, obtuse to rounded at
the apex P. scabrilinguis
39b. Lip without a conspicuous narrow claw at the base, more or less acute or
apiculate at the apex 40
40a. Leaves linear to lanceolate-oblong, 8.5 cm. or less long; sepals 6 mm. or
less long; dorsal sepal narrower than the lamina of the united lateral sepals.
P. juninensis var. angustifolia
40b. Leaves ovate-oblong or elliptic-oblong, 10 cm. or more long; dorsal sepal
slightly broader than the lamina of the united lateral sepals.
P. juninensis var. subaequisepala
41a. Plant small, mature leaves 4 cm. or less long; lamina of the united lateral
sepals broadly ovate, not gradually narrowed above, about 3.7 mm. long.
P. graciliscapa
41b. Plant relatively large, mature leaves 5 cm. or more long; lamina of the
united lateral sepals lanceolate-ovate, distinctly narrowed above, 5.7 mm.
or more long P. juninensis
42a. Secondary stems distinctly separated on an elongated rhizome 43
42b. Secondary stems approximate, either with, or generally without, a creep-
ing rhizome (in P. frutex and var., the base of the much-branched stems
has not been collected) 44
43a. Dorsal sepal much longer and narrower than the lateral sepals; petals
serrate, much shorter than the sepals P. fimbriata
43b. Dorsal sepal about equal to the lateral sepals; petals with entire margins,
about as long as the sepals P. trachychlamys
44a. Dorsal sepal and petals with a long-clavate, fleshy apex; stem concealed
by loose, maculate sheaths P. fimbrilabia
44b. Dorsal sepal and petals not long-clavate above; stem generally without
loose, maculate sheaths 45
45a. Leaf oval, rounded above, rounded to broadly cuneate below, abruptly
petioled; lip with narrow lobes near the base P. ringens
45b. Leaf not oval, varying from oblong or elliptic to linear-elliptic or oblong-
lanceolate 46
46a. Lip triapiculate at the more or less broadened apical part.
P. Talpinaria (P. trimeroglossa)
46b. Lip not triapiculate above 47
47a. Flowers large, sepals about 2 cm. or more long 48
47b. Flowers small, sepals about 1.8 cm. or less long 51
48a. Outer surface of the sepals densely short-pubescent P. serripetala
48b. Outer surface of the sepals glabrous 49
49a. Flowers 1-4, distinctly pedicellate; sepals linear-lanceolate to oblong-
lanceolate; base of the lip with a pair of abbreviated lobes or auricles. .50
SCHWEINFURTH: ORCHIDS OF PERU 265
49b. Flowers numerous, subsessile; sepals all subulate-attenuate from an ovate-
lanceolate base; lip without basal auricles. . .P. Poeppigii (P. myoxanthus)
50a. Mid-lobe of the lip filiform, with entire margins P. tentaculata
50b. Mid-lobe of the lip oblong-oblanceolate, with erose or pubescent margins.
P. hemirhoda
51a. Lip suborbicular, disc with a pair of conspicuous bilobed humps.
P. Archidonae
51b. Lip not suborbicular, either ovate or oblong 52
52a. Disc of the lip with a central callus near the base and a prominent clavate-
thickened mid-nerve near the apex; petals linear-attenuate.
P. ruscifolia (P. multicaulis)
52b. Disc of the lip without a central callus near the base or a clavate-thickened
mid-nerve above 53
53a. Flowers sessile or nearly so 54
53b. Flowers distinctly pedicelled 55
54a. Stems copiously branched; leaves up to 9.2 cm. long; anterior part of the
lip more or less narrower than the basal part P. frutex
54b. Stems few-branched; leaves up to 16 cm. long; anterior part of the lip as
broad as or broader than the basal part P. frutex var. robusta
55a. Perianth elongate; sepals lanceolate-linear P. affinis
55b. Perianth abbreviated; sepals lanceolate or oblong-lanceolate.
P. rigidifolia
56a. Petals serrate to fimbriate or pubescent (sometimes obscurely so) 57
56b. Petals entire on the margins, very rarely irregular in places or minutely
papillose 72
57a. Flowers large, sepals 3.5 cm. or more long; petals subequal to the sepals;
raceme erect, much surpassing the leaf. . . .P. phalangifera 1 (P. Mathewsii)
57b. Flowers relatively small, sepals 1.8 cm. or less long; petals distinctly
shorter than the sepals 58
58a. Inflorescence much longer than the subtending leaf, erect 59
58b. Inflorescence shorter than the leaf, or, if longer, nodding or diffuse 60
59a. Petals and lip abruptly narrowed above the middle P. scabrata
59b. Petals and lip not abruptly narrowed above P. cilidta var. elongala
60a. Leaf deeply cordate at the base; stems terete P. trachysepala*
60b. Leaf very shortly cordate to cuneate at the base 61
61 a. Racemes not subtended by a large and conspicuous spathe 62
61b. Racemes subtended by a large and conspicuous spathe; petals pubescent.
P. spathata
62a. Inflorescences arising from the base of the leaf 63
62b. Inflorescences arising above the base of the leaf 68
1 The flowers of this concept (as Acronia phalangifera) were described as having
a bipartite lip, but the species was placed as a synonym of P. Mathewsii by Lindley
(Fol. Orch. Pleurothallis p. 8, no. 30. 1859) without comment. There seems to be
no reasonable doubt that P. phalangifera and P. Mathewsii are conspecific.
2 This species, which has the general appearance of the section of Pleurothallis
having cordate leaves with 1 -flowered inflorescences, is described as having few-
flowered racemes. However, judged from a photograph of the vegetative parts
and from most of the description, the concept might be referable even to P.
cordata (Ruiz & Pav.) Lindl.
266 FIELDIANA: BOTANY, VOLUME 30
63a. Lip sharply 3-lobed near the base 64
63b. Lip simple or subsimple (at most with rounded and indistinct lateral
lobes) 66
64a. Petals with a distinct narrow claw P. Smithiana
64b. Petals without a distinct narrow claw 65
65a. Flowers glabrous without; petals bicarinate in the middle; lateral lobes of
the lip triangular P. carinata
65b. Flowers finely short-pubescent without; petals without keels; lateral lobes
of the lip semiovate P. ciliata var. abbreviate/,
66a. Stems gradually dilated upward (usually markedly so); racemes abbrevi-
ated, densely flowered, commonly fascicled; dorsal sepal 5.5 mm. or less
long 67
66b. Stems uniform above and below; racemes somewhat shorter than the leaf,
loosely flowered in course of development, single or rarely 2; dorsal sepal
about 8 mm. or more long P. ciliata
67a. Leaf ovate to elliptic, only about twice as long as wide or wider; dorsal
sepal narrowly oblong, membranaceous P. chamensis var. tennis
67b. Leaf ovate-oblong or oblong-lanceolate to narrowly oblong, about three
times as long as wide or narrower; dorsal sepal obovate-oblong, fleshy.
P. verruculosa
68a. Petals deeply lacerate on each side above P. phyllostachys
68b. Petals merely serrate to crenate-serrate or denticulate 69
69a. Sides of the petals notably dissimilar; petals sharply acuminate or awned,
with a short keel in the middle in front P. decurrens
69b. Sides of the petals closely similar; petals without a sharp point at the
apex or keel on the disc 70
70a. Leaves gradually long-cuneate toward the base; sepals pubescent on the
outer surface; petals sharply truncate at the apex P. pantasmoides
70b. Leaves rounded to subcordate (rarely broadly cuneate) at the base;
sepals glabrous on the outer surface; petals acute to broadly obtuse at
the apex 71
71 a. Lip when expanded oblong-ovate, without elevated margins in front;
ovary glabrous or essentially so P. chamensis
71b. Lip when expanded oblong-obovate, with elevated margins throughout;
ovary tomentose P. casapensis
72a. Base of the inflorescence with a more or less conspicuous and coriaceous,
conduplicate spathe which is commonly 2.5 cm. or more long 73
72b. Base of the inflorescence without a conspicuous or elongate spathe. . . .85
73a. Petals elongate, usually acute or acuminate, subequaling the sepals ... 74
73b. Petals relatively short, markedly shorter than the sepals 79
74a. Leaf suborbicular (a little longer than wide), shallowly cordate at the
base; lip sharply 3-lobed P. penduliflora
74b. Leaf ovate to elliptic (much longer than wide), usually cuneate to rounded
at the base 75
75a. Lip transverse, i.e., broader than long when expanded, sharply genicu-
late in the middle 76
75b. Lip not transverse, i.e., noticeably longer than broad, not sharply genic-
ulate 77
76a. Inflorescence densely or subdensely many-flowered; flowers small, sepals
6.2 mm. or less long; lip simple or subsimple. .P. diffusa (P. semipellucida)
SCHWEINFURTH: ORCHIDS OF PERU 267
76b. Inflorescence loosely many-flowered; flowers relatively large, sepals about
11 mm. long; lip lightly 3-lobed.
P. diffusa var. grandiflora (P. semipellucida var. grandiflora)
77a. Lip markedly shorter than the petals, rather abruptly narrowed above
the middle; petals slightly broader near the base.
P. pedunculata var. peruviana
77b. Lip subequal to the petals, very gradually long-acuminate from near the
base; petals more or less abruptly lanceolate-dilated near the base. . . .78
78a. Plant stout; raceme subequaling or slightly exceeding the leaf; lamina
of the united lateral sepals bidentate above; lip prominently navicular.
P. lanceolata
78b. Plant slender; raceme usually much exceeding the leaf; lamina of the
united lateral sepals entirely coalescent; lip concave but not navicular.
P. Schweinfurthii (P. lanceolata var. gracilis)
79a. Apex of the petals abruptly acute; lip with an abrupt, long claw. .P. trulla
79b. Apex of the petals obtuse to rounded or truncate; lip without a claw. .80
80a. Lip sharply acute; lateral sepals free; flowers relatively small, less than
5 mm. long P. fons florum
80b. Lip subobtuse to rounded or retuse; lateral sepals more or less connate;
flowers larger, about 6 mm. or more long 81
81a. Lamina of the lip slightly but distinctly 3-lobed 82
81b. Lamina of the lip simple 83
82a. Plant stout; racemes 4 or more to a plant; flowers white; sepals finely
pubescent within; mid-lobe of the lip nearly as long as broad. .P. Vargasii
82b. Plant relatively slender; raceme solitary; flowers reddish yellow; sepals
nearly glabrous within; mid-lobe of the lip transverse P. cyathiflora
83a. Leaf ovate-subrotund, distinctly petioled P. cauliflora
83b. Leaf oblong to oblong-elliptic, sessile 84
84a. Flowers relatively large, about 18-20 mm. long; sepals straight 1 and
parallel P. Crocodilanthe
84b. Flowers relatively small, about 13 mm. or less long; lateral sepals strongly
decurved when viewed from the side P. Cassidis
85a. Sepals deeply carinate throughout, with a distinct, more or less high
wing 86
85b. Sepals not deeply carinate with a distinct wing throughout 87
86a. Petals much surpassing the column, long-acuminate; floral bracts incon-
spicuous, apparently not carinate P. carnosifolia
86b. Petals about equaling the column, acute; floral bracts conspicuous,
dorsally carinate P. tricarinata
87a. Petals distinctly broader above the middle or, if oblong or elliptic-lanceo-
late, broadly rounded to retuse (rarely acute) at the apex 88
87b. Petals distinctly narrowed toward the apex or linear (rarely clavate-
thickened near the tip) 105
88a. Lamina of the lip quadrate when expanded, with a fleshy callus at each
corner in front P. quadrata
88b. Lamina of the lip not quadrate when expanded and without fleshy mar-
ginal calli 89
89a. Lip broader above the middle or with the posterior and anterior halves
about equally broad 90
89b. Lip distinctly narrowed above the middle 97
268 FIELDIANA: BOTANY, VOLUME 30
90a. Sepals broadly oval or suborbicular-ovate, not much longer than broad,
deeply cucullate; leaf narrowly lanceolate-elliptic, narrowed toward both
ends P. divaricans
90b. Sepals oblong to elliptic-lanceolate or linear-lanceolate, much longer than
broad 91
9 la. Lip cuneate-obovate, minutely auriculate at the base, lamina traversed
by 3 lines P. nigro-hirsuta 1
91b. Lip cuneate-oblong, oblanceolate-oblong or pandurate 92
92a. Lamina of the lip constricted in the middle, with the basal half not much
narrower than the anterior half, provided with a pair of more or less con-
spicuous fleshy keels below or in the middle; sepals acute or acuminate. . 93
92b. Lamina of the lip not constricted in the middle, or if so (sometimes in
P. gelida) markedly narrower in the lower half 95
93a. Lamina of the leaf oblong to elliptic-oblong, 12 mm. (rarely) or more
wide; keels in the basal half of the lip 94
93b. Lamina of the leaf linear-oblong, 10 mm. or less wide; keels more promi-
nent in the middle of the lip P. tenuifolia
94a. Sepals lanceolate, acute or short-acuminate; lip rounded or truncate-
subretuse at the apex P. rubens
94b. Sepals linear-lanceolate, long-acuminate; lip prominently retuse at the
apex P. excisa
95a. Leaf narrowly linear with revolute margins, many times longer than
broad, up to 5 mm. wide in the dried specimen.
P. tenuifolia var. longisepala
95b. Leaf oblong to oval, not many times longer than broad, 1 cm. or more
wide; lip bicarinate in the middle 96
96a. Sepals lanceolate, long-narrowed above, about 11-16 mm. long, lateral
sepals not saccate at the base; lip oblong-obovate.
P. aurea (P. asperilinguis)
96b. Sepals oblong-lanceolate or broader, about 8 mm. long, lateral sepals
saccate at the base; lip cuneate P. gelida
97a. Base of the lip with an abrupt, more or less elongate claw 98
97b. Base of the lip without an abrupt, elongate claw, very shortly clawed or
cuneate at the base 101
98a. Inflorescences much shorter than the leaf; leaf elliptic to elliptic-ovate or
oval P. vaginata (P. umbraticola)
98b. Inflorescences longer than the leaf; leaf elliptic-linear or oblong to short-
ligulate 99
99a. Lip without a prominently narrowed or lobed anterior portion . . P. Trulla
99b. Lip with a prominent, narrow or lobed anterior portion 100
lOOa. Rachis of the raceme not fractiflex; flowers subapproximate . . .P. dilatata
lOOb. Rachis of the raceme strongly fractiflex; flowers very remote.
P. flexuosa (P. remotiflora)
lOla. Sepals linear or linear-lanceolate, relatively elongate; anterior part of the
lip papillose P. stenopetala
lOlb. Sepals ovate or oblong to elliptic-lanceolate (rarely suborbicular), rela-
tively short; anterior part of the lip not papillose 102
1 This species appears to be closely allied to P. aurea Lindl.
SCHWEINFURTH: ORCHIDS OF PERU 269
102a. Racemes loosely few-flowered; lateral sepals connate into an ovate-
suborbicular, deeply concave lamina; petals fleshy- thickened above.
P. bicornis
102b. Racemes densely many-flowered; lateral sepals not forming a suborbicular
lamina; petals not fleshy-thickened above 103
103a. Mid-lobe of the lip retuse; petals truncate or subtruncate above.
P. retusiloba
103b. Mid-lobe of the lip not retuse; petals acute to rounded above 104
104a. . Petals 3-nerved; leaves narrow, oblong-oblanceolate to linear-oblong, 1.5
cm. or less wide; rachis of the raceme stout P. trilineata 1
104b. Petals 1-nerved (rarely with 1 or 2 indistinct lateral nerves toward the
base); leaves relatively broad, lanceolate-elliptic to oval; rachis of the
raceme slender P. velaticaulis (P. Pittieri)
105a. Inflorescences longer than the leaf, usually much so 106
105b. Inflorescences shorter than the leaf, usually much so 114
106a. Leaf suborbicular, shallowly cordate at the base; lip 3-lobed with incurved,
oblong lateral lobes P. penduliflora
106b. Leaf not suborbicular (varying from oval or ovate to linear-oblong), com-
monly cuneate to rounded at the base; lip, if 3-lobed, without incurved,
oblong lateral lobes 107
107a. Plant small, usually about 11 cm. or less high; inflorescence only rarely
surpassing the leaves P. pruinosa
107b. Plant relatively large, about 13 cm. or more high; inflorescence commonly
much surpassing the leaves 108
108a. Flowers large, about 15-20 mm. long; petals elliptic-lanceolate.
P. restrepioides
108b. Flowers small, about 11 mm. or less long; petals linear, oblong-linear,
lanceolate-linear or filiform, sometimes more or less clavate above. . . . 109
109a. Uppermost internode of the stem very short; lip spreading, distinctly
3-lobed, much broader than long P. antennifera
109b. Uppermost internode of the stem not abbreviated 110
HOa. Racemes few-flowered, loose; flowers large, sepals commonly about 10 mm.
long P. secunda var. longiracema (P. Lindenii var. longiracema)
HOb. Racemes many-flowered, more or less dense; flowers usually small, sepals
7 mm. or less long Ill
Ilia. Plant relatively small, stems 11.5 cm. or less long; leaf petioled, 1.8 cm.
or less wide; flowers not bilabiate P. angustipetala
lllb. Plant commonly large, stems usually 19 cm. or more long; leaf sessile, 3.3
cm. or more wide; flowers bilabiate 112
112a. Lip ovate or ovate-lanceolate, distinctly longer than broad.
P. xanthochlora (P. huanucoensis)
112b. Lip transverse, ovate-semiorbicular, broader than long 113
113a. Inflorescences dense or subdense; flowers small, sepals 6.2 mm. or less long.
P. diffusa (P. semipellucida)
113b. Inflorescences loosely flowered; flowers relatively large, sepals about 11
mm. long. . .P. diffusa var. grandiflora (P. semipellucida var. grandiflora)
114a. Anterior part of the lip conspicuously fimbriate-dentate P. bicornis
114b. Anterior part of the lip not fimbriate-dentate 115
1 This concept may prove to be a variant of P. velaticaulis.
270 FIELDI ANA: BOTANY, VOLUME 30
115a. Lip with a prominent claw or narrow basal portion, acute or apiculate
above 116
115b. Lip sessile or nearly so, without a prominent, narrow, basal portion . . .117
116a. Petals narrowly linear, lightly sigmoid; lateral lobes of the lip broad, sub-
orbicular-aliform; leaf subpetiolate-attenuate below P. genychila
116b. Petals linear-lanceolate, not sigmoid; lateral lobes of the lip obliquely
obtriangular; leaf with a distinct, narrow petiole P. tunguraguae
117 a. Outline of the lip suborbicular-ovate to ovate or broadly obovate. . . .118
117b. Outline of the lip oblanceolate-oblong to linear : . . . 120
118a. Plant small, leaf 4.5 cm. or less long; lip gradually narrowed to the acute
or acuminate apex P. pruinosa
118b. Plant large, leaf 7.5 cm. or more long; lip broadly rounded in front (some-
times with an abruptly acute apex) 119
119a. Lip ovate or suborbicular-ovate, often minutely and abruptly acute, bical-
lose at the base with widely separated calli P. secunda (P. Lindenii) 1
119b. Lip broadly obovate, rounded and obtuse in front, unicallose at the base.
P. Cajamarcae
120a. Leaf broader above the middle; lip more or less acute P. obovata
120b. Leaf not broader above the middle; lip obtuse 121
121a. Shape of the leaf elliptic, 1.5 cm. or more wide; sepals about 5 mm. long;
lip about 3 mm. long P. angustildbia (P. citrina var. elliptica)
121b. Shape of the leaf oblong-ligulate, 1.1 cm. or less wide; sepals 7-8 mm. long;
lip about 2 mm. long P. citrina
Pleurothallis acuminata (HBK.) Lindl. Bot. Reg. 28, Misc. 70,
no. 13. 1842; Reichb. f. Bonpl. 2: 24. 1854; Lindl. Fol. Orch. Pleuro-
thallis 33, no. 198. 1859. Dendrobium acuminatum HBK. Nov.
Gen. etSp. 1:357. 1816.
Plant rather large, epiphytic, about 45 cm. high. Stem abbreviated, angled,
sheathed, monophyllous. Leaf oblong or elliptic-oblong, narrowed to the base
and apex, about 5 cm. long, up to 1.9 cm. wide. Inflorescences 1-2, up to 15 cm.
long, strict, flowering to the base. Flowers apparently yellowish red. Sepals
scarcely spreading, glabrous, subequal, linear-lanceolate, acuminate, about 13
mm. long. Petals three or four times shorter than the sepals, narrowly oblong,
acute. Lip slightly longer than the petals, oblong, attenuate above and below,
obtuse or retuse at the apex, near the base undulate-constricted on each side,
with 3 carinate nerves. Column slender, shorter than the petals and lip, winged,
with a cucullate, denticulate apex.
Prov. of Jaen de Bracamoros, near the district of Pomahuaca,
according to HBK.
This concept appears to be too inadequately described to present
a clear diagnosis and so is not entered in the key.
1 In the original description and figure of this species, the lip was shown as
long-clawed, but a flower from the type proves this characterization to be er-
roneous.
SCHWEINFURTH: ORCHIDS OF PERU 271
Pleurothallis acutiflora (Ruiz & Pav.) Mansf. ined. = obscure
species. Humboldtia acutiflora Ruiz & Pav. Syst. Veg. Fl. Peruv.
etChil. 1:236. 1798.
Huanuco: Pozuzo, on trees and rocks, Ruiz & Pavon s.n.
Pleurothallis affinis Lindl. Hook. Comp. Bot. Mag. 2: 354.
1836; Fol. Orch. Pleurothallis 16, no. 81. 1859. Humboldtia affinis
0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891.
Plant large. Stem stout, basal portion of type (incomplete) about 13 cm.
tall, unifoliate. Leaf erect, sessile or nearly so, narrowly lanceolate, narrowed to
an acute, tridentate apex, cuneate below, about 30 cm. long and 3 cm. wide.
Inflorescences abbreviated, numerous, 1-flowered, in a dense glomerule. Flowers
long-pedicelled, very small. Sepals "linear" or lanceolate-linear, long-attenuate;
all free, apparently about 7 mm. long. Petals similar but narrower. Lip much
smaller, arcuate in natural position, oblong-ovate, obtuse, short-unguiculate with
the sides of the lower portion erect. Column semiterete, little shorter than the
lip, with a pair of narrow teeth on either side of the clinandrium, produced into
a distinct foot. Ovary pubescent.
Peru: Habitat not recorded, Matthews 1899.
This concept, represented in the Ames Herbarium only by
a photograph of the type collection with a rather incomplete floral
analysis drawn by Lindley, is a rather obscure species and may be
identical with P. rigidifolia Reichb. f.
Pleurothallis amygdalodora Kranzl. Engler Bot. Jahrb. 37:
521. 1906.
Plant small or very small. Stems densely caespitose, few-branched or super-
posed above, filiform, up to 10 cm. tall, several-jointed, entirely concealed by
close, tubular, lepanthiform sheaths with a spreading hispid mouth. Leaves oval
to suborbicular-obovate, up to 1.5 cm. long including the short petiole and 8 mm.
wide, obtuse to retuse above, cuneate below, more or less fleshy. Inflorescences
axillary, commonly solitary, much surpassing the leaves, few- (up to 15-) flowered,
very loosely flowered; rachis slender-filiform, more or less fractiflex; pedicels
elongate. Flowers small, but large for the plant, membranaceous, white. Dorsal
sepal from an ovate, strongly cucullate base gradually long-caudate, 6-8 mm. long.
Lateral sepals about equally long, from a lanceolate base narrowed into a long-
caudate apex. Petals much smaller than the sepals, oblong-oblanceolate, oblique,
acute. Lip larger than the petals, oblong-ovate in outline, shallowly 3-lobed near
the cuneate base; about 2 mm. long and 1 mm. wide below; lateral lobes short,
semiobovate; mid-lobe lanceolate-oblong and obtuse. Column slender, nearly
equaling the petals, with a pair of rounded wings above.
Cajamarca: Prov. of Hualgayoc, Valley of the Taolis, 2800
meters, in thickets of evergreens rich in sclerophyllous forms,
Weberbauer 4824 (type). Cuzco: Prov. of Convencion, Hda.
Potrero, Sapan-Sachayocc, 2200 meters, epiphytic in forest, Vargas
272 FIELDIANA: BOTANY, VOLUME 30
2585. Junin: La Merced, Hacienda Schunke, about 1230 meters,
epiphytic, Macbride 5781.
Pleurothallis angustilabia Schltr. Fedde Repert. Beih. 9: 71.
1921; Mansf. Fedde Repert. Beih. 57: t. 113, nr. 442. 1929. PUu.ro-
thallis citrina Schltr. var. elliptica C. Schweinf. Bot. Mus. Leafl.
Harvard Univ. 16: 9. 1953.
Plant medium-sized, up to 25 cm. tall. Rhizome abbreviated. Stems more
or less approximate, 7-15 cm. long, monophyllous, 3- to 4-jointed, with several
close, tubular sheaths. Leaf erect or nearly so, distinctly petioled; lamina elliptic
or oblong-elliptic, subacute to obtuse, 3.5-10 cm. long, up to 3 cm. wide; petiole
6-20 mm. long. Inflorescences 2 to numerous, much shorter than the leaves,
loosely up to 12-flowered, rarely up to 7.3 cm. long. Flowers small, membra-
naceous, greenish to yellow, glabrous. Dorsal sepal lanceolate to broadly lanceo-
late, acuminate or long-acuminate, strongly concave, 5-7 mm. long. Lateral
sepals similar, about as long as the dorsal sepal but slightly narrower, oblique
and lightly falcate. Petals a little shorter than the sepals, from an oblong basal
portion long-acuminate, subfalcate. Lip oblong-linear to narrowly oblong,
lightly arcuate, rather fleshy, obtuse to rounded at the apex, up to 3 mm. long!
Column about a half or a third as long as the petals, terminating in a rather
abrupt wing which is irregularly dentate at the subtruncate apex.
Cuzco: Prov. of Urubamba, Machu-Picchu, Sta. Rita, 2500
meters, on rocks, Vargas 3344- Valle de Santa Ana, Bues s.n.,
fide Herrera, Sin. Fl. Cuzco 1: 196. 1941. Junfn: Between Panti
and Rocchas, 2000 meters, Weberbauer 6540 (type of P. angustilabia).
-Puno: Prov. of Carabaya, Ollachea (abajo), 2500 meters, on
rocks, Vargas 6936 (type of P. citrina var. elliptica).
Pleurothallis angustipetala C. Schweinf. Bot. Mus. Leafl.
Harvard Univ. 16: 45, t. 5. 1953. Figure 46.
Plant medium-sized, slender, with a creeping rhizome. Stems in pairs,
slender, monophyllous, 4-11.5 cm. long, with 3 or 4 close, tubular sheaths. Leaf
erect, petioled, up to 7.2 cm. long; lamina oblong-elliptic, acute or obtuse, cuneate
below, up to 6.5 cm. long and 1.8 cm. wide. Inflorescence solitary, nearly twice
as long as the leaf, about 12.2 cm. or less long, densely or subdensely many-
flowered above, looser below. Flowers commonly secund, yellow-green, with
spreading segments. Sepals minutely cellular-papillose within. Dorsal' sepal
narrowly lanceolate, long-narrowed to an acute apex, up to 9.8 mm. long. Lateral
sepals obliquely lanceolate, gently recurved above, subequally long with the
dorsal sepal and a little wider. Petals scarcely more than half as long as the
sepals, linear, acute. Lip sigmoid when viewed from the side, somewhat longer
than the petals, pandurate-oblong, obtuse or subacute, about 5.9 mm. long; basal
portion subquadrate-oblong, with a pair of low keels; anterior portion slightly
longer and broader, oblong-ovate, up to 2.1 mm. wide. Column small, shorter
than the petals, about 3 mm. long.
FIG. 46. Pleurothallis angustipetala C. Schweinf. 1, plant; X K- 2, flower,
expanded; X 3K- 3, column and lip from side, natural position; X S 1 A-
273
274 FIELDI ANA: BOTANY, VOLUME 30
Cuzco: Prov. of Paucartambo, Pillahuata, 2800 meters, epi-
phyte, Vargas 4956 (type). Same locality, 3200 meters, epiphytic
in rain-forest, "ceja de montana," Vargas 3006a.
Pleurothallis antennifera Lindl. Fol. Orch. Pleurothallis 30,
no. 178. 1859. Humboldtia antennifera 0. Ktze. Rev. Gen. PI.
pt. 2: 667. 1891.
Plant medium-sized, up to 34 cm. high from the long creeping rhizome.
Secondary stems distant, monophyllous, up to 18 cm. high, slender, with the
uppermost internode relatively short and provided with a ventricose, acute,
carinate sheath. Leaf oblong-ovate or lanceolate-elliptic, erect, narrowed to an
obtuse apex, cuneate at the subsessile or shortly petioled base, up to 7.6 cm. long
and 2.5 cm. wide. Inflorescence solitary, slender-racemose, arcuate-suberect,
up to 18.8 cm. long, densely many-flowered, secund. Flowers rather small,
ringent, pale green, bilabiate, about 7 mm. long. Dorsal sepal ovate-lanceolate,
acuminate, concave. Lateral sepals connate into an ovate acute lamina which
is much broader than the dorsal sepal. Petals filiform-linear, erect, obtuse. Lip
very small, triangular in outline, nearly twice as broad as long, 3-lobed near the
base, with the lateral lobes dwarf and rounded and the mid-lobe much larger,
ovate-triangular and acute. Column short, stout, truncate.
"Peru"(?), fide Schlechter, Fedde Repert. Beih. 9: 139. 1921.
Ecuador (type).
This diagnosis was prepared with the aid of a photograph of the
type bearing a floral analysis, from the Lindley Herbarium at Kew.
Pleurothallis arbuscula Lindl. Bot. Reg. 28, Misc. 72, no. 32.
1842; Fol. Orch. Pleurothallis 32, no. 193. 1859. Humboldtia arbus-
cula O. Ktze. Rev. Gen. PI. pt. 2: 667. 1891.
Plant slender, medium-sized, about 24 cm. or less tall. Stems caespitose,
slender, proliferating or with a few ascending branches above, remotely few-
leaved in the upper part, up to 18 cm. high, entirely concealed by close, tubular,
lepanthiform sheaths with an erect-spreading mouth. Leaves erect, shortly
petioled; lamina elliptic or "oval," acute and mucronate, cuneate below, up to
3.3 cm. long and 1 cm. wide. Racemes solitary, far surpassing the leaf, up to 9 cm.
long, flexuous or arcuate, subdensely many-flowered, secund. Perianth segments
only little spreading. Sepals free, linear, obtuse, about 1.3 cm. long. Petals
dwarf, broadly oblong, rounded above. Lip about twice as long as the petals,
linear-oblong or "ligulate," rounded at the apex, bicarinate through the basal half.
Cajamarca, fide Schlechter, Fedde Repert. Beih. 9: 139. 1921.
Ecuador (type).
This description was made by examining a photograph of the
type with floral analysis, from the Lindley Herbarium at Kew.
Pleurothallis Archidonae Lindl. Fol. Orch. Pleurothallis 15,
no. 74. 1859; Kranzl. Xen. Orch. 3: 171, t. 299, fig. III. 9-13. 1900;
SCHWEINFURTH: ORCHIDS OF PERU 275
Fedde Repert. 1 : 179. 1905. Humboldtia Archidonae 0. Ktze. Rev.
Gen. PI. pt. 2: 667. 1891.
Plant tall, over 56 cm. high. Stems few, crowded, up to about 40 cm. or
more tall, unifoliate, bearing several short sheaths. Leaf erect, elliptic-lanceolate
or oblong, acute or short-acuminate, cuneate at the sessile base, up to 22 cm. long,
3-6 cm. wide. Inflorescences fascicled in the leaf-axil. Flowers successive, brown
to purple, rather large, bilabiate. Dorsal sepal ovate-oblong or oblong-lanceolate,
acute, 1-1.8 cm. long. Lateral sepals connate into a deeply concave, suborbicular
lamina, which is slightly shorter but much broader than the dorsal sepal. Petals
elliptic-lanceolate or "ovate-lanceolate," acute, a little shorter than the dorsal
sepal, minutely crenulate. Lip minute, cordate-suborbicular, with a pair of
conspicuous bilobed humps, one on each side. Column a little longer than the lip.
Cajamarca: Prov. of Chota, near Huambos, 2400-2500 meters,
in a thicket of mixed trees and shrubs, Weberbauer 4%01, fide Kranzl.
Ecuador (type).
This diagnosis was prepared by the aid of a photograph of the
type bearing a floral analysis, from the Lindley Herbarium.
Pleurothallis attenuata Rolfe, Kew Bull. (1909) 364.
Plant small, caespitose. Stems very short, concealed by sheaths, mono-
phyllous. Leaf small, shortly petioled, up to 3.3 cm. long; lamina oblong-elliptic,
minutely 3-denticulate at the apex, cuneate below, up to 2.7 cm. long and 10 mm.
wide. Peduncle and rachis filiform, up to 8 cm. long, loosely 2- to 4-flowered.
Flowers large for the plant, with subparallel segments, green marked with purple.
Sepals similar, free. Dorsal sepal lanceolate-linear, acute or subacute, about 1.6
cm. long. Lateral sepals linear, slightly shorter and narrower than the dorsal
sepal. Petals linear or linear-lanceolate, subacute, markedly shorter than the
sepals, pubescent on the margins. Lip relatively minute, about one fourth to one
third as long as the sepals, oblong to narrowly ovate-oblong, lightly constricted
in the middle, obtuse to truncate at the apex, with the margins serrate to minutely
erose, about 3-4 mm. long and 1 mm. wide; a tuberculate keel extends through
the middle of the anterior part. Column a little shorter than the lip, arcuate,
broadly winged above.
Habitat unknown. Peru(?), fide Schlechter, Fedde Repert. Beih.
9: 139. 1921.
Pleurothallis aurea Lindl. Ann. & Mag. Nat. Hist. 12: 397.
1843; Fol. Orch. Pleurothallis 33, no. 201. 1859. Pleurothallis asperi-
linguis Reichb. f. & Warsc. Bonpl. 2: 114. 1854; Lindl. Fol. Orch.
Pleurothallis 34, no. 202. 1859. Humboldtia asperilinguis O. Ktze.
Rev. Gen. PI. pt. 2: 667. 1891. Humboldtia aurea 0. Ktze. I.e.
Plant small to medium-sized, with an abbreviated rhizome, variable, about
9-26 cm. high. Stems crowded, unifoliate, 2-9 cm. high, the lower part with 2-5
close, tubular, evanescent sheaths. Leaf erect-spreading, sessile to short-petioled ;
276 FIELDI ANA: BOTANY, VOLUME 30
lamina oblong-elliptic (rarely elliptic or oblong), acute and apiculate to rounded
at the apex, cuneate below, thickly coriaceous, about 2.7-8.7 cm. long, up to 2.2
cm. wide. Inflorescences much exceeding the leaf, usually 1 or 2 (rarely 3), erect
or suberect, racemose, subdensely many-flowered, often floriferous nearly to the
base, up to 23 cm. long. Flowers commonly secund, medium-sized, campanulate,
green to yellow. Sepals free, short-pubescent or papillose within. Dorsal sepal
lanceolate to linear-lanceolate, long-acuminate or gradually narrowed to an acute
apex, about 10-16.5 mm. long. Lateral sepals very similar, but often slightly
longer, somewhat oblique. Petals about half as long as the dorsal sepal, obovate-
oblong to cuneate-oblong, acute to rounded at the tip, 3-nerved. Lip about as
long as the petals, arcuate below, oblong-obovate when expanded, obtuse to
rounded in front, about 4.8-5.6 mm. long and 2 mm. or more wide above the
middle; disc with a pair of thickened nerves, fleshy parallel ridges or keels ex-
tending from near the base to the upper portion. Column small, stout or slender,
with an apically denticulate wing.
Peru: Habitat not recorded, Warscewicz s.n. (type of P. asperilin-
guis). Puno: Prov. of Carabaya, below Ollachea, 2500 meters, on
rocks, Vargas 6941 - Also Venezuela (type of P. aurea) and Ecuador.
Pleurothallis bicornis Lindl. Fol. Orch. Pleurothallis 7, no. 29.
1859; C. Schweinf. Bot. Mus. Leafl. Harvard Univ. 15: 84. 1951.
Humboldtia bicornis 0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891.
Plant large, up to 59 cm. or more tall. Stems approximate on the woody
rhizome, monophyllous, up to 45.5 cm. high, with 2 or 3 close, tubular sheaths
(the upper one remote). Leaf erect (erroneously called deflexed), oblong-ovate
(rarely ovate or elliptic), commonly lightly cordate at the sessile base, subacute
to short-acuminate, up to 15.5 (rarely 24) cm. long, 3.5-12 cm. wide. Inflo-
rescences 1 to several, fascicled, diffuse or nodding, more or less shorter than the
leaf, loosely several-flowered. Flowers medium-sized, ringent, bilabiate, white or
translucent with red or violet stripes. Dorsal sepal oblong-lanceolate or narrowly
elliptic-lanceolate, acute, up to 13.5 mm. long. Lateral sepals connate into an
ovate-suborbicular lamina which is minutely bidentate at the apex, about as long
as the dorsal sepal but much broader. Petals obliquely oblong-lanceolate or
oblong-oblanceolate, fleshy (especially above), obtuse, somewhat shorter than
the dorsal sepal. Lip minute, abruptly reflexed or geniculate near the base, with
the sides of the basal part erect and the flat forward portion suborbicular-ovate
and irregularly dentate, up to 3 mm. long and wider in natural position; disc near
the base with a pair of short, erect, fleshy keels extended into the erect basal
sides. Column minute, about equaling the lip, dilated above.
Amazonas, fide Schlechter, Fedde Repert. Beih. 9: 139. 1921.
Cuzco: Prov. of Calca, Vilcabamba, 2700 meters, on shrubby slopes,
Vargas 3947. Prov. of Convention, Hda. Potrero, Sapan-Sachayocc,
2200 meters, epiphytic in forest, Vargas 2548. Huanuco: Mito, about
2770 meters, on ledges of shrubby hillsides, Macbride 8286. Same
locality and altitude as the last, on steep southwestern slope, Mac-
bride & Feather stone 1397 (fruit).
SCHWEINFURTH: ORCHIDS OF PERU 277
Pleurothallis brevispicata C. Schweinf. Bot. Mus. Leafl. Har-
vard Univ. 10: 173, t. 17, figs. 8-14. 1942. Figure 51.
Plant small, up to 12 cm. high. Stems slender, caespitose, up to 10 cm. long,
monophyllous (rarely superposed), entirely concealed by 5-7 close, tubular,
lepanthiform sheaths with a spreading, hispid mouth. Leaf small, elliptic to
linear-elliptic, acute, narrowed below into a more or less distinct petiole, up to
4.6 cm. long and 7 mm. wide. Inflorescences 1-5, shorter than or slightly sur-
passing the leaf, loosely few- (up to 9-) flowered, generally arcuate in course of
development. Flowers small, membranaceous, greenish white. Dorsal sepal
ovate or ovate-lanceolate, concave, acute or short-acuminate, about 6-8 mm.
long. Lateral sepals shorter than the dorsal sepal, obliquely lanceolate or nar-
rowly lanceolate, connate near the base, long-acuminate. Petals about half as
long as the dorsal sepal, oblong-obovate, broadly rounded above. Lip nearly as
small as the petals, recurved in natural position, ovate-oblong when expanded,
broadly rounded in front, sessile at the base, prominently bicarinate near the base,
3-3.6 mm. long, about 2 mm. wide across the dilated basal part. Column ab-
breviated, with a conspicuous subquadrate foot.
Huanuco: Yanano, about 1800 meters, dense epiphyte, Macbride
3838 (type.) Tambo de Vaca, about 3900 meters, flowers greenish
white, on trees, Macbride 4$44, 4461 a. Alturas del Chaco, Santa
Ana Valley, Herrera 2124 (Bues coll.).
Pleurothallis Cajamarcae Schltr. Fedde Repert. Beih. 9: 73.
1921; Mansf. Fedde Repert. Beih. 57: t. 113, nr. 444. 1929.
Plant large, erect, up to 75 cm. tall, with an abbreviated rhizome. Stem
slender, monophyllous, provided with 4 or 5 close, tubular sheaths, up to 55 cm.
long. Leaf erect or nearly so, oblong-lanceolate, acute, sessile with a subrounded
base, up to 20 cm. long and nearly 5 cm. wide. Racemes 2 to 4, pendulous, up to
10 cm. long, loosely 5- to 8-flowered above. Flowers medium-sized, glabrous,
pale brown. Dorsal sepal lanceolate, "narrowly oblong," subobtuse, concave,
about 11 mm. long. Lateral sepals connate into an ovate, obtuse, concave lamina
which is about as long as the dorsal sepal but much broader. Petals slightly
shorter than the sepals, linear-lanceolate, falcate, acute or acuminate, minutely
papillose. Lip small, about a third as long as the sepals, sessile, geniculate,
obovate in outline, broadly rounded above, with a depressed, apiculate callus at
the base, scarcely 4 mm. long. Column very_short and stout, dilated above,
footless.
Cajamarca: Huambos, 2400-2500 meters, Weberbauer 4201.
Pleurothallis carinata C. Schweinf. Bot. Mus. Leafl. Harvard
Univ. 15: 85, t. 24. 1951. Figure 47.
Plant rather small, epiphytic, with a creeping rhizome which is concealed by
close, scarious sheaths. Stems about 2 cm. apart, 5.5-6 cm. tall, 1- or 2-jointed,
not broadened above, unifoliate at the apex, with 2 or 3 close, tubular sheaths
below. Leaf erect, oblong-elliptic, subacute to obtuse, sessile at the broadly
PLEUROTHALLIS
cartnaicL
C, Scfuri&'inf/
FIG. 47. Pleurothallis carinala C. Schweinf. 1, plant; X %. 2, flower from
side; X 2%. 3, petal; X 5. 4, column and lip from side; X 5. 5, lip from above,
natural position; X 5.
278
SCHWEINFURTH: ORCHIDS OF PERU 279
cuneate base, about 8.4 cm. long and 2.15 cm. wide, fleshy-coriaceous. Inflo-
rescences 1 or 2, very short, loosely racemose and 2-flowered above, about 1.5
cm. long. Flowers dark yellow, bilabiate. Dorsal sepal narrowly oblong-lanceo-
late, acuminate, concave below, with a fleshy, lightly recurved upper portion,
about 10 mm. long. Lateral sepals connate into a deeply concave, ovate-lanceo-
late, bidentate lamina which is slightly shorter than the dorsal sepal but about
twice as wide. Petals about half as long as the sepals, oblong-lanceolate, sharply
acute, somewhat dilated unequally on each side of the base, minutely serrulate
above the middle, with the inner surface bicarinate through the middle. Lip
slightly shorter than the petals, oblong-ovate, abruptly acute and apiculate,
provided on each side near the base with a small, erect, triangular lobule, about
5 mm. long and 2 mm. wide; disc shortly bicarinate above the middle. Column
slender, arcuate, with a deeply dentate wing above, slightly shorter than the lip.
Cuzco: Prov. of Quispicanchis, Murayaca, Marcapata, 1300-
1600 meters, Vargas 3757.
Pleurothallis carnosifolia C. Schweinf. Bot. Mus. Leafl. Har-
vard Univ. 15: 87, t. 25. 1951. Figure 48.
Plant small, inconspicuous, up to 8 cm. tall. Stems caespitose, short, uni-
foliate, entirely concealed by 3-5 close, tubular sheaths, up to 3 cm. high. Leaves
erect, narrowly elliptic or oblanceolate, very fleshy and usually conduplicate in
the dried specimen, acute or subacute, gradually narrowed to a sessile or scarcely
petioled base, up to 5.5 cm. long and 1.4 cm. wide. Inflorescences axillary,
fascicled, 4-7, racemose above, commonly subequaling or exceeding the leaf, very
loosely 3- to 5-flowered. Flowers large for the plant, fleshy, campanulate, yellow
and coffee-color. Sepals conspicuously carinate without, recurved above. Dorsal
sepal linear-lanceolate, long-narrowed to an acute tip, concave below, about 9.5
mm. long. Lateral sepals very similar to the dorsal sepal but slightly narrower.
Petals similar to the sepals but smaller, linear-lanceolate, acuminate, locally
erose. Lip much smaller than the other segments, simple, lightly arcuate-recurved
with erect sides and about 4 mm. long in natural position, lanceolate-ovate,
acute, rounded at the base and 1.3 mm. wide when expanded. Column small,
about half as long as the lip, denticulate at the truncate apex, with a prominent
fleshy foot.
Cuzco:. Prov. of Urubamba, Salapunco (Km. 84), 2400 meters,
on mossy rocks, Vargas 5989.
Pleurothallis casapensis Lindl. Bot. Reg. 28, Misc. 76, no. 61.
1842; Fol. Orch. Pleurothallis 13, no. 60. 1859. Humboldtia casa-
pensis 0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891.
Plant rather small, with a creeping rhizome, up to 18 cm. high (apex of erect
leaf incomplete in the type). Stems more or less separated on the rhizome, erect
or spreading, monophyllous, 4-angulate or narrowly bialate, up to 9 cm. high.
Leaf oblong-ovate, lightly cordate or broadly rounded at the base, subacute to
obtuse at the apex, decurrent on the stem, up to about 9 cm. long and 3.6 cm. wide.
Raceme several-flowered, spicate, about half as long as the leaf or less. Flowers
PLEUROTHALLIS
carnosifolia
FIG. 48. Pleurothallis carnosifolia C. Schweinf. 1, plant; X IK- 2, another
leaf with upper part of stem; X %. 3, lip, three quarters view; X 6. 4, dorsal
sepal; X 4. 5, petal; X 4. 6, column with lateral sepal; X 4.
280
SCHWEINFURTH: ORCHIDS OF PERU 281
small, yellow, smooth, with pubescent ovary. Sepals fleshy. Dorsal sepal oblong-
oblanceolate, acute. Lateral sepals connate into an ovate-oblong bidentate
lamina which is slightly longer than the dorsal sepal. Petals thinner, about half
as long as the lateral sepals, narrowly elliptic-lanceolate, acute, serrate above the
middle. Lip fleshy, slightly longer than the petals, oblong-obovate, acute, concave,
with the margins elevated and lightly serrulate. Column slender, shorter than
the petals.
Huanuco: Cassapi (Casapi), MathewslSSO (type). Also Ecuador.
The description was amplified by a photograph of an Ecuadorian
collection of P. casapensis bearing a floral analysis, from the Lindley
Herbarium.
Pleurothallis Cassidis Lindl. Ann. & Mag. Nat. Hist. 15: 384.
1845; Fol. Orch. Pleurothallis 3, no. 5. 1859. Humboldtia Cassidis
0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891.
Plant large, stout, caespitose, variable throughout, with an abbreviated
rhizome. Stems commonly crowded, up to 41.5 cm. long, unifoliate, provided
at the base and near the middle with a tubular, evanescent sheath, the upper one
being elongate and rather loose. Leaf oblong-elliptic or broadly oblong, obtuse,
sessile with an amplexicaul base, 10-20 cm. long, 3-5 cm. wide, thickly coriaceous.
Inflorescences axillary, 3 to numerous, erect to diffuse, subequaling or surpassing
the leaf, up to about 19 cm. long, many-flowered almost to the base, subtended by
a prominent conduplicate spathe 3-5.5 cm. long. Flowers small, translucent,
whitish or yellow, lined with maroon. Dorsal sepal strongly galeate and 5.5-13
mm. long in natural position, ovate-elliptic when expanded, acute or apiculate.
Lateral sepals connate through the lower half into a suborbicular to oblong-ovate,
deeply concave lamina which is much shorter than the dorsal sepal. Petals
broadly oblong to obovate-oblong, oblique, obtuse to rounded at the apex, 3-
nerved, more or less shorter than the lateral sepals. Lip suborbicular to sub-
orbicular-oblong, rounded to slightly retuse at the apex, provided with a short
keel on each side near the middle of the lateral margin, about 2-4 mm. long and
subequally wide or more or less narrower. Column minute, about half as long
as the lip.
Cuzco : Prov. of Paucartambo, Pillahuata, 2700 meters, epiphyte,
Vargas 4960. Huanuco: Prov. of Huanuco, near Chinchao, Carpish
Pass, about 2760 meters, epiphyte in mossy forest, Hodge 6280.
Also Colombia (type).
Pleurothallis caudatipetala C. Schweinf. Bot. Mus. Leafl.
Harvard Univ. 10: 175, t. 22, figs. 5-8. 1942. Figure 64.
Plant very small, caespitose, 1.5-3.5 cm. high. Stems abbreviated, congested,
unifoliate, concealed by 2 tubular, evanescent sheaths, up to 4 mm. long. Leaf
obovate to cuneate-spatulate, up to 15 mm. long and 5 mm. wide, subacute to
rounded at the apex, cuneate below. Inflorescences commonly solitary, shorter
than or surpassing the leaf, 1-flowered to loosely several- (11-) flowered. Flowers
282 FIELDIANA: BOTANY, VOLUME 30
small, campanulate, membranaceous. Sepals varying from glabrous to sparingly
long-ciliate. Dorsal sepal oblong-lanceolate, acute, concave near the base, about
3.6 mm. long. Lateral sepals connate into an elliptic-ovate, bidentate lamina
which is slightly longer and much wider than the dorsal sepal. Petals a little
shorter than the sepals, with the lower half obovate-oblong and the upper half
abruptly caudate. Lip minute, pandurate-oblong, lightly retuse at the broad
apex, with the margins (except near the base and middle) fimbriate, about 2 mm.
or less long and 1 mm. wide where broadest. Column shorter than the lip, dilated
upward, broadly winged throughout, lobulate with denticulate margins at the
apex.
Cuzco: Prov. of Urubamba, Machu-Picchu, 2040 meters, on rocks,
Vargas 3367. Huanuco; Prov. of Huanuco, west of Divisoria, 1400
meters, epiphyte in forest, Asplund 12619. Junin: Chanchamayo
Valley, 1500 meters, Schunke 1307 (type).
Pleurothallis caulescens Lindl. Hook. Journ. Bot. 1: 9. 1834;
Fol. Orch. Pleurothallis 44, no. 280. 1859. Humboldtia caulescens
0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891. Pleurothallis graminea
Schltr. Fedde Repert. Beih. 9: 74. 1921; Mansf. Fedde Repert. Beih.
57: t. 114, nr. 447. 1929.
Plant small, caespitose, up to 16 cm. tall. Stems crowded, slender, dis-
tichously leafy, entirely concealed by the leaf-sheaths. Leaves small, linear or
linear-lanceolate (sometimes elliptic-linear), unjointed, up to 2.9 cm. long and
4.5 mm. wide (the uppermost being the largest), obtuse and apiculate, sessile,
spreading. Racemes terminal, 1-4, rather densely several- to many-flowered,
up to 10.5 cm. tall. Flowers membranaceous, rather small, yellow, with spreading
segments. Dorsal sepal lanceolate to linear-lanceolate, very acute or acuminate,
concave, 4.5-6 mm. long. Lateral sepals similar but smaller, long-acuminate
(rarely subobtuse), connate near the base. Petals about half as long as the sepals,
obliquely oblanceolate or rhombic-oblanceolate (elliptic-ovate), acute or obtuse.
Lip much shorter than the petals, ovate in outline, 3-lobed below the middle with
the lateral lobes semiobovate and rounded and the larger mid-lobe ovate or
oblong-elliptic and commonly retuse at the rounded apex, about 1.5 mm. long,
and 1.1 mm. wide across the lateral lobes. Column abbreviated.
Cuzco: Near Sandia, 2600-2800 meters, on branches in the shade
in dense thicket, Weberbauer 758 (type of P. graminea Schltr.).
Puno, fide Schlechter, Fedde Repert. Beih. 9: 139. 1921. Ecuador
(type of P. caulescens}.
A photograph of the type of P. caulescens with a floral analysis,
from the Lindley Herbarium, as well as Ecuadorian material referred
to this species, aided the above diagnosis.
Pleurothallis cauliflora Lindl. Hook. Comp. Bot. Mag. 2: 355.
1836; Hook. Ic. PI. 1: t. 50. 1837; Fol. Orch. Pleurothallis 4, no. 10.
1859. Humboldtia cauliflora 0. Ktze. Rev. Gen. PL pt. 2: 667. 1891.
SCHWEINFURTH: ORCHIDS OF PERU 283
Plant large, up to 39.3 cm. tall. Stem rather slender, monophyllous, up to
20 cm. high, provided with 3 tubular sheaths of which the uppermost is largest
and widely separated. Leaf distinctly petioled; lamina ovate-suborbicular, about
8.2 cm. long and 6 cm. wide, rounded at the apex, broadly rounded at the base;
petiole about 2 cm. long. Inflorescences 4-4, much surpassing the leaf, about
20 cm. or less long, densely or subdensely many-flowered, secund, diffuse, sub-
tended by a conspicuous spathe up to 3.4 cm. long. Flowers rather large, bi-
labiate. Dorsal sepal ovate, obtuse, about 10 mm. long. Lateral sepals connate
into an ovate, concave, bidentate lamina which is markedly shorter than the
dorsal sepal. Petals about half as long as the dorsal sepal, ovate-oblong or "linear,"
obtuse. Lip somewhat shorter than the petals, suborbicular, broadly rounded or
retuse at the apex, ecallose. Column about as long as the lip, clavate.
Cajamarca, fide Schlechter, Fedde Repert. Beih. 9: 139. 1921.
Ecuador (type).
The above diagnosis was prepared chiefly from a photograph of
the type bearing a floral analysis, from the Lindley Herbarium at Kew.
Pleurothallis chamaelepanthes Reichb. f. Bonpl. 3: 240. 1855;
Lindl. Fol. Orch. Pleurothallis 26, no. 154. 1859. Humboldtia cha-
maelepanthes 0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891.
Plant small, slender, up to about 10 cm. high. Stems very slender, some-
times short-branched or proliferous above, up to about 7.6 cm. long, entirely
invested by close, pubescent sheaths with a spreading hispid mouth. Leaf abrupt-
ly short-petioled; lamina oval to oblong-elliptic ("oblong"), subacute to emargin-
ate at the apex, marginate, up to 1.2 cm. long and 7 mm. wide. Inflorescence
solitary, axillary, capillary, a little surpassing the leaf, few- (about 2-) flowered,
about 2 cm. or less long. Flowers small, yellow, membranaceous, long-pedicelled.
Dorsal sepal lanceolate or ovate-lanceolate, concave below, tapering to a long
subulate apex, with the margins minutely scabrous. Lateral sepals subequal but
perhaps narrower, bifid nearly to the base. Petals very short (about a third as
long as the dorsal sepal), obliquely ligulate, obtuse. Lip oblong-ovate in outline,
short-clawed, 3-lobed near the base, apparently a little longer than the petals;
lateral lobes dwarf, semiobovate or "acinacif orm" ; mid-lobe much longer, ovate-
oblong ("ligulate"), obtuse. Column small, slender, with a pair of small denti-
form lateral lobules near the apex.
Peru: Tacna, Valley of Lloa (Loa), on trees, Jameson 313 (type).
This diagnosis was largely compiled from drawings of this con-
cept, from the Reichenbach Herbarium.
Pleurothallis chamensis Lindl. Orch. Linden. 2, no. 7. 1846;
Fol. Orch. Pleurothallis 13, no. 59. 1859; Kranzl. Engler Bot. Jahrb.
54, Beibl. 117, p. 21. 1916. Humboldtia chamensis 0. Ktze. Rev.
Gen. PI. pt. 2: 666. 1891.
Plant variable, small to medium-sized, 6.2-23 cm. high, commonly with a
creeping rhizome. Stems more or less separated, unifoliate, 3.5-15 cm. long,
284 FIELDIANA: BOTANY, VOLUME 30
angled, narrowly bialate above, more or less dilated upward, with 1 or 2 close,
tubular, evanescent sheaths at the base. Leaf erect or erect-spreading, broadly
oval to oblong-elliptic or ovate to oblong-ovate, rounded, obtuse or acute above,
rounded to shortly cordate (rarely broadly cuneate) at the sessile base, with the
lower part shortly decurrent on the apex of the stem, 2.7-10.5 cm. long, up to 4.7
cm. broad. Inflorescences 1 to several, commonly much shorter than the leaf
(rarely subequaling the leaf), rising above the base of the leaf, racemose, densely
few- to several-flowered. Flowers greenish yellow or yellow to orange-tan, rather
small, more or less fleshy, ringent. Dorsal sepal linear-oblong to oblanceolate-
oblong, acute (rarely obtuse), up to 10 mm. long. Lateral sepals connate into an
elliptic or lanceolate-elliptic, sharply bidentate lamina, which is rather shorter
than the dorsal sepal. Petals about half as long as the lateral sepals, elliptic-
lanceolate to rhombic-oblanceolate (rarely spatulate), acute (rarely obtuse),
serrate to sharply fimbriate-dentate above the middle. Lip simple, ovate-oblong
to Ungulate with upcurved sides near the base in natural position, broadly rounded
in front (rarely acute) with the anterior margins minutely serrulate to erose-
dentate, shortly cuneate at the base, with a pair of indistinct, intramarginal keels
below the middle, up to 4.6 mm. long and 2.2 mm. wide above the middle. Column
small, subequaling the petals, arcuate, dilated above with a denticulate apex.
Ayacucho: Aina, between Huanta and Rio Apurimac, 750-1000
meters, epiphytic in open woods, Killip & Smith 22842. Huanca-
velica: Prov. of Tayacaja, Ampurco, Salcabamba-Surcubamba Trail,
2900 meters, epiphytic on moss-covered trees in fog zone, Stork &
Horton 10421. Junin: Huacapistana, about 1800 meters, epiphyte
in densely forested valley, Killip & Smith 24285 (spatulate petals).
Piura: Prov. of Huancabamba, on the western slopes of the Cordi-
llera east of Huancabamba, near Hacienda Chantaco, 2500 meters,
in sclerophyllous thickets consisting of trees and shrubs, Weberbauer
6313. Also Colombia and Venezuela (type).
Pleurothallis chamensis Lindl. var. tenuis C. Schweinf. Bot.
Mus. Leafl. Harvard Univ. 10: 176. 1942.
Plant differs from the type in being more slender, up to 10.5 cm. tall, with
apparently caespitose stems, ovate to elliptic, more acute leaves (up to 4.5 cm.
long and 2.3 cm. wide) and flowers which are very similar to those of the type,
but more membranaceous in texture and noted as "dark maroon with yellow-
tipped petal." ,
Huanuco: District of Churubamba, Hacienda Mercedes, Coti-
rarda, 1560 meters, epiphytic on tree trunks, Mexia 821 5a.
Pleurothallis chanchamayoensis Schltr. Fedde Repert. Beih.
9: 73. 1921; Mansf. Fedde Repert. Beih. 57: t. 113, nr. 445. 1929.
Plant erect, slender, about 35 cm. tall, with an abbreviated rhizome. Stem
terete, with 3 close, brown, tubular sheaths in the lower half, monophyllous, up
to 31 cm. long. Leaf horizontal, ovate, rather long-acuminate, deeply cordate
SCHWEINFURTH: ORCHIDS OF PERU 285
with overlapping auricles at the sessile base, up to 12 cm. long (including the
basal auricles) and 6 cm. wide. Inflorescences abbreviated, 1-flowered, fascicled.
Flowers medium-sized. Dorsal sepal lanceolate, narrowed to an obtuse apex,
concave, 9 mm. long. Lateral sepals connate into a concave, ovate-lanceolate,
obtuse lamina, which is as long as the dorsal sepal, and situated on the upper side
of the flower. Petals about half as long as the sepals, lanceolate-linear, lightly
falcate, subacute. Lip shorter than the petals, elliptic-obovate or "oblong-
ligulate" in outline, acute, auriculate-cordate at the base, about 3.5 mm. long
and 1.8 mm. wide in the middle, somewhat constricted near the base, provided
with a basal, semielliptic excavation. Column very short and stout, with a short
subulate rostellum.
Junin: Near La Merced in the Chanchamayo Valley, A. & C.
Kohler s.n.
Pleurothallis ciliaris (Lindl.) L. 0. Wms. Caldasia no. 5: 14.
1942. Specklinia ciliaris Lindl. Bot. Reg. 24, Misc. 31, no. 40.
1838.
Plant small, caespitose, 5-14 cm. high. Stems slender, unifoliate, spreading,
more or less flexuous, up to 9 cm. long, entirely concealed by close tubular sheaths
which terminate in a conspicuously spreading, ovate-infundibuliform, hispid-
margined mouth. Leaf erect, linear-elliptic, lanceolate or elliptic, acute or obtuse,
narrowed to a scarcely petioled base, up to about 6.6 cm. long and 1.3 cm. wide.
Inflorescences axillary, few to very numerous, usually a half or a third as long as
the leaf, few- to several-flowered. Flowers very small, ringent, dark purple or
purple-red (rarely green or yellow), membranaceous. Sepals ciliate, especially
above. Dorsal sepal ovate or oblong-ovate*, concave, acute, up to 3 (rarely 4) mm.
long. Lateral sepals similar, obliquely oblong-ovate, connate near the base. Petals
about half as long as the sepals, oblong or ovate-oblong, obtuse, ciliate. Lip with
a small narrow claw; lamina oblong, oblanceolate-oblong or obovate-oblong, often
slightly constricted in the middle, broadly rounded at the apex, slenderly bi-
auriculate at the base, ciliate, with a more or less prominent keel below, about
2 mm. long and 1 mm. wide across the convex apical portion. Column short,
arcuate, about as long as the petals or longer, broadly winged above, trilobulate
at the apex.
Cuzco: Prov. of Quispicanchis, San Pedro to Murayaca, Marca-
pata, 1200-1800 meters, on rocks, Vargas 5207. Prov. of Urubamba,
Machu-Picchu, 2040 meters, on rocks, Vargas 3406.
A widespread species extending from Mexico (type of Specklinia
ciliaris') through Central America to Costa Rica and here first noted
from South America.
Pleurothallis ciliata Knowl. & Westc. Flor. Cab. 1: 1. 19. 1837;
Lindl. Fol. Orch. Pleurothallis 24, no. 140. 1859; Reichb. f. Saunders
Refug. Bot. 2: t. 142. 1882; Cogn. Martius Fl. Bras. 3, pt. 4: 537.
1896. Humboldtia ciliata 0. Ktze. Rev. Gen. PL pt. 2: 667. 1891.
286 FIELDIANA: BOTANY, VOLUME 30
Plant small to medium-sized, with a creeping rhizome, up to 19 cm. high
from the rhizome to the tip of the erect leaf. Stems approximate or more or less
separated on the rhizome, monophyllous, up to 8 cm. long, stout or slender, more
or less angulate in section when dry, with 2 or 3 tubular, imbricating, evanescent
sheaths below. Leaf elliptic to oblong or oblanceolate, acute to obtuse, cuneate
at the sessile base, up to 11.6 cm. long and 2.9 cm. wide. Inflorescence commonly
solitary, spreading to arcuate, more or less shorter than the leaf, loosely several-
flowered above, up to 9 cm. long. Flowers rather small, bilabiate, fleshy, glabrous,
yellow to orange. Dorsal sepal linear to narrowly elliptic-lanceolate, acute or
acuminate, up to 13.7 mm. long. Lateral sepals obliquely oblong-lanceolate,
connate into an ovate-oblong or elliptic-oblong, concave, sharply bidentate lamina
which is subequally long with the dorsal sepal but about twice as broad. Petals
about a third to a half as long as the sepals, lanceolate to elliptic-oblong, acute to
acuminate, more or less deeply serrate or ciliate. Lip about as long as the petals or
shorter, shortly clawed, about 4 mm. or less long, lightly recurved; claw callose-
thickened in the middle; lamina obovate-oblong in natural position or oblong-
ovate when expanded from a cuneate or subtruncate base, with the sides of the
lower portion erect-incurved and more or less angled, broadly rounded and some-
times abruptly acute in front, denticulate or shortly fimbriate, with a pair of
remote, more or less distinct, fleshy keels near the middle. Column small, clavate,
arcuate, shorter than the petals, with a denticulate wing above, up to 3 mm.
long.
Loreto : Mishuyacu, near Iquitos, 100 meters, epiphyte in forest,
Klug 1471. Vicinity of Iquitos, 100 meters, river side on living tree,
Klug 10050. Also British Guiana (type), Trinidad and Colombia.
Pleurothallis ciliata Knowl. & Westc. var. abbreviata
C. Schweinf. Bot. Mus. Leafl. Harvard Univ. 16: 46. 1953.
Form differing from the type in its abbreviated inflorescences, densely pu-
bescent outer surface of the flowers and distinct lateral lobules of the lip.
Plant variable, medium-sized to large. Stems monophyllous, 6-27 cm. long.
Leaf erect, oblong-elliptic, subacute, cuneate at the sessile base, 9-14 cm. long, up
to 3.5 cm. wide. Inflorescences 1 or 2 (perhaps more), abbreviated, nodding,
densely few-flowered. Flowers small, finely short-pubescent without, bilabiate,
brownish yellow, somewhat striped with darker brown-yellow. Dorsal sepal
narrowly oblong-lanceolate, acute and mucronate, up to 9.4 mm. long, 3- to
5-nerved. Lateral sepals connate into an elliptic-lanceolate, sharply bidentate
lamina which is about as long as the dorsal sepal but nearly twice as wide. Petals
less than half as long as the sepals, elliptic-lanceolate, short-acuminate, serrate
above. Lip smaller than the petals, lightly arcuate below, ovate-oblong, rounded
at the apex, 3-lobulate above the cuneate base with a pair of small, erect, denti-
form, obtuse lateral lobules, bicarinate through the middle, about 2.2 mm. long.
Column about as long as the lip, abruptly dilated above.
Huanuco: Yanano, about 1800 meters, on mossy tree, Macbride
3837 (type). Junin: Chanchamayo Valley, 1200 meters, Schunke
1127 (whole plant very small).
SCHWEINFURTH: ORCHIDS OF PERU 287
Pleurothallis ciliata Knowl. & Westc. var. elongata C. Schweinf.
Bot. Mus. Leafl. Harvard Univ. 16: 47. 1953.
Form differing from the type in having elongate inflorescences that much
surpass the leaves and long-caudate petals.
Plant medium-sized, with a creeping rhizome. Stems slender, monophyllous,
5-8 cm. long, about 1 cm. or more apart. Leaf erect, oblong-elliptic to oblong-
oblanceolate, acute, cuneate at the sessile base, up to 7.7 cm. long and 2 cm. wide.
Inflorescences 1 or 2, much exceeding the leaf, arcuate to lax, loosely several-
flowered above, about 18 cm. or less long. Flowers rather small, bilabiate, greenish
yellow striped with red-brown, glabrous. Dorsal sepal narrowly lanceolate-
oblong, acute and apiculate, about 14 mm. long. Lateral sepals connate into
a broadly oblong, apically bidentate lamina which is about as long as the dorsal
sepal and twice as wide. Petals half as long as the sepals, oblong-lanceolate,
long-caudate above, lacerate-dentate above the base (especially on the anterior
margin). Lip short-clawed, about 4 mm. long; claw with a fleshy U-shaped callus;
lamina oblong-ovate, obtuse, subtruncate below, erose-denticulate, with a pair of
remote, obscure, carinate thickenings below. Column small, arcuate, wing-
dilated above, about 3 mm. high.
Loreto : Vicinity of Iquitos, 100 meters, on living tree in clearing,
King 10013.
Pleurothallis citrina Schltr. Fedde Repert. Beih. 7: 103. 1920;
Mansf. Fedde Repert. Beih. 57: t. 35, nr. 135. 1929.
Plant small, up to about 15 cm. tall. Rhizome abbreviated. Stems approxi-
mate to 5 mm. apart, slender, monophyllous, 3.5-9.5 cm. long, provided with
3 or 4 close, tubular, evanescent sheaths. Leaf erect, indistinctly petioled;
lamina oblong-linear to linear-elliptic, obtuse, gradually narrowed below, 3.5-8.5
cm. long, up to 1.1 cm. wide. Inflorescences fascicled, several, abbreviated, much
shorter than the leaves, laxly few-flowered, 1-3 cm. long. Flowers small, "lemon
yellow." Sepals triangular-linear or linear-lanceolate, long-attenuate to a sub-
obtuse apex, about 7-8 mm. long. Lateral sepals similar, oblique. Petals nar-
rowly-lanceolate, long-attenuate above, somewhat shorter than the sepals. Lip
minute, simple, less than half as long as the petals, oblanceolate-oblong, obtuse,
convex, about 2 mm. long. Column minute, dilated above.
Huanuco: Huacachi, near Muna, about 2000 meters, epiphyte,
Macbride 4070. (Some of the stems and leaves are longer than typ-
ical and the leaves are narrower; but this collection is very advanced.)
Colombia (type).
Pleurothallis cordata (Ruiz & Pav.) Lindl. Gen. & Sp. Orch. 5.
1830; Reichb. f. Bonpl. 2: 26. 1854; Lindl. Fol. Orch. Pleurothallis 10,
no. 44. 1859. Humboldtia cordata Ruiz & Pav. Syst. Veg. Fl. Peruv.
et Chil. 1: 234. 1798. Stelis cordata Willd. Sp. PI. 4: 140. 1805.
Pleurothallis brachyblephara Schltr. Fedde Repert. Beih. 9: 72. 1921;
Mansf. Fedde Repert. Beih. 57: t. 113, nr. 443. 1929.
288 FIELDIANA: BOTANY, VOLUME 30
Plant tall, stout, from an abbreviated rhizome. Stems approximate, up to
48 cm. high, monophyllous, with about 3 close, tubular sheaths below. Leaf
widely spreading, ovate to suborbicular, deeply cordate at the base (commonly
with overlapping auricles), abruptly acute or acuminate, up to 14.8 cm. long
including the basal auricles and 9.4 cm. wide. Inflorescences abbreviated, 1-
flowered, fascicled, subtended by a large conduplicate, evanescent spathe. Flowers
small for the plant, bilabiate. Dorsal sepal oblong-oval (rarely obovate-oval) to
suborbicular, rounded to subacute at the apex, 6-9 mm. long. Lateral sepals
connate to form an ovate-suborbicular, concave lamina which is a little shorter
than the dorsal sepal and usually more or less broader than long. Petals falcate,
oblong-lanceolate, decurved, acute, erose-ciliolate, shorter than the lateral sepals.
Lip fleshy, shorter than or subequaling the petals, shortly-clawed; lamina sub-
quadrate-ovate or suborbicular-ovate (rarely suborbicular-obovate), obtuse to
acute, with the anterior margins ciliolate, up to 3 mm. long and more or less
narrower. Column abbreviated, stout.
Peru: Pillao, Pavdn (type). Ayacucho: Aina, between Huanta
and Rio Apurimac, 750-1000 meters, epiphyte in open woods, Kil-
lip & Smith 22569, 23168. Ccarrapa, between Huanta and Rio
Apurimac, 2800 meters, terrestrial on wooded hillside, Killip & Smith
22290. Cuzco: Near Sandia, 2300 meters, on rocky slopes, Weber-
bauer 635 (type of P. brachyblephara) . Prov. of Convention, Hda.
Potrero, Sapan-Sachayocc, 2200 meters, epiphyte in dense forest,
Vargas 2546. Prov. of Quispicanchis, "Ttio a Murayaca i Marca-
pata," 1960 meters, on open rocks, Vargas 3136. Valle de Cosnipata,
between Mistiana and Kuros, about 800 meters, Scolnik 880. Hua-
nuco: Carpish, 2750 meters, Scolnik 1076. Between Huanuco and
Pampayaco (Pampayacu), Kanehira 336 (no fls.). Muna, on trail
to Tambo de Vaca, about 2500 meters, "tree-base," Macbride 4335.
Twelve miles south of Panao, about 3100 meters, on wet banks among
rotting wood, Macbride & Featherstone 2206. Panao, about 2700
meters, on shrubby slopes, Macbride 3608. Junin: Pichis Trail,
Porvenir, 1500-1900 meters, epiphyte in dense forest, Killip &
Smith 25890.
A variable species, particularly in the flowers which range from
deep red, dull reddish, green tinged with red, dark brown, purple,
obscurely reddish green, or chestnut with yellow streaks.
Pleurothallis crateriformis C. Schweinf. Bot. Mus. Leafl.
Harvard Univ. 15: 88, t. 26. 1951. Figure 49.
Plant caespitose, medium-sized, epiphytic. Stems spreading, slender, uni-
foliate, up to 14.5 cm. high, with about 3 close, tubular, evanescent sheaths which
are densely fine-pubescent, the upper sheath separated and much the longest.
Leaf horizontally spreading or reflexed, broadly ovate, deeply cordate at the base
with overlapping auricles, abruptly acute with a minutely tridenticulate tip,
PLEUROTHALLIS
craTerijo rmis
L.
FIG. 49. Pleurothallis crateriformis C. Schweinf. 1, plant; X 1 A. 2, flower,
expanded; X 3. 3, lip, three quarters view; X 5J^.
289
290 FIELDIANA: BOTANY, VOLUME 30
up to 8.7 cm. long from the apex to the tip of an auricle and 5 cm. wide. Inflo-
rescences abbreviated, 1-flowered, 1 to several, in the axil of an evanescent,
conduplicate spathe. Flowers small, bilabiate, dark red without, pale brown with
dark red lines inside. Dorsal sepal round-ovate, acute with a minute, incurved
point, with 3 prominent veins on either side of a double central vein, about 8 mm.
long and slightly narrower. Lateral sepals connate into an oblong-ovate, concave,
obtuse lamina which is slightly longer but much narrower than the dorsal sepal.
Petals lanceolate-linear, gently recurved, gradually narrowed to a subacute apex,
conspicuously shorter than the sepals. Lip simple, ovate, deeply concave-saccate
throughout, subacute with a minute incurved point, cordate at the base, the large
cavity surrounded on each side by a broad, fleshy, flattened margin, about 4 mm.
long and 3 mm. wide. Column stout, abbreviated.
Junin: Prov. of Tarma, Agua Dulce, 2000 meters, epiphyte in
low highland forest, Woytkowski 35487.
Pleurothallis Crocodilanthe Lindl. Fol. Orch. Pleurothallis 4,
no. 9. 1859. Crocodeilanthe xiphizusa Reichb. f. & Warsc. Bonpl. 2:
114. 1854; Xen. Orch. 1: 10, t. 6, fig. I, 1-7. 1854. Pleurothallis
xiphizusa Reichb. f. Walp. Ann. 6: 172. 1861.
Plant apparently large. Stem stout, monophyllous (basal portion incomplete
in the record). Leaf erect, oblong-elliptic, rounded and apiculate at the apex,
sessile at the cuneate base, about 16 cm. long and 5 cm. wide. Inflorescence
solitary, racemose, up to 24 cm. long, rather densely many-flowered through the
upper half, subtended by a conspicuous spathe about 4.5 cm. long. Flowers
large, secund, with the horizontally parallel sepals about 2 cm. long, bilabiate.
Dorsal sepal oblong-lanceolate, acute or subacute. Lateral sepals subequal,
connate into a concave, ovate-elliptic, bidentate lamina. Petals about a third to
a half as long as the dorsal sepal, obliquely oblong-cuneate to obovate, retuse and
apiculate or subacute at the broad apex. Lip suborbicular, ecallose, obtuse to
rounded above, a little shorter than the petals, about 5 mm. long and broad.
Column slender, about equaling the petals, dilated below and above.
Huanuco, Junin, fide Schlechter, Fedde Repert. Beih. 9: 140.
1921. Loreto(?) : Source of the Rio Maranon, Warscewicz s.n. (type).
The above description was drawn from a photograph with floral
analysis of this concept, from the Lindley Herbarium, as well as from
an analysis of Crocodeilanthe xiphizusa, contributed by Mr. Garay.
Pleurothallis cyathiflora C. Schweinf. Bot. Mus. Leafl. Har-
vard Univ. 15: 90, t. 27. 1951. Figure 50.
Plant stout, rather large, epiphytic. Stems approximate, unifoliate, arcuate
in the type, about 20 cm. or less long, with a long, tubular, evanescent sheath
above the middle. Leaf ascending, short-petioled; lamina oblong-elliptic, rounded
at the apex and at the base, up to 12.5 cm. long and 3.8 cm. wide; petiole short,
channelled, up to 1 cm. long. Inflorescence solitary, subequaling or exceeding the
leaf, subdensely many-flowered above, surrounded at the base by a prominent,
PLEUROTHALLIS
cyathi 'flora
FIG. 50. Pleurothallis cyathiflora C. Schweinf. 1, plant; X 14. 2, flower
from side; X 3%. 3, petal; X 3%. 4, dorsal sepal, partially expanded; X 3%.
5, lateral sepal; X 3%. 6, lip, three quarters view; X 3%. 7, lip, expanded;
291
292 FIELDIANA: BOTANY, VOLUME 30
conduplicate spathe up to 2.4 cm. long. Floral bracts conspicuous, spreading,
infundibuliform. Flowers reddish yellow, campanulate. Dorsal sepal suborbi-
cular-ovate, deeply concave, rounded to subacute at the apex, about 7 mm. long.
Lateral sepals semiconnate or free, oblong-ovate, abruptly subacute, slightly
oblique, somewhat longer and narrower than the dorsal sepal. Petals conspicu-
ously smaller than the sepals, broadly oblong or elliptic-oblong, truncate to
broadly rounded and bluntly subacute at the apex. Lip somewhat shorter than
the petals, oblong and tubular-concave with upcurved sides in natural position,
rhombic-obovate and 3-lobed when expanded, cuneate below, about 4.2-4.5 mm.
long and 4 mm. wide; lateral lobes shallowly semiobovate; mid-lobe transversely
elliptic-oblong; disc with a fleshy callus on each side at the sinus and with a lower
semicircular callus in the center below. Column small, somewhat dilated below.
Cuzco: Prov. of Paucartambo, Pillahuata, 2800 meters, Vargas
4957.
Pleurothallis declivis Lindl. Fol. Orch. Pleurothallis 36, no. 218.
1859. Humboldtia declivis 0. Ktze. Rev. Gen. PL pt. 2: 667. 1891.
Plant very small, with a creeping rhizome, up to 7 cm. high from the rhizome
including the nodding raceme. Stems numerous, more or less approximate,
ascending from a decumbent base, very short, monophyllous, provided with 2 or 3
close, tubular sheaths, up to 1.9 cm. long. Leaf erect, tapering into a more or less
elongate slender petiole, up to 5 cm. long; lamina elliptic to linear-oblanceolate,
up to 3 cm. long and 4.5 mm. wide. Inflorescence solitary, filiform, about two or
three times as long as the leaf, with the floriferous upper portion loosely few-
flowered and commonly decurved. Flowers very small, secund. Dorsal sepal
ovate or subrotund, concave, broadly obtuse, about 2.7 mm. long. Lateral sepals
obliquely linear-oblong, obtuse or subacute, free, somewhat longer than the dorsal
sepal. Petals dwarf, about half as long as the dorsal sepal, oblong-subquadrate,
truncate at the apex. Lip very small, about as long as the petals but narrower,
pandurate-oblong, broadly rounded to subtruncate in front, concave above and
below with a transverse fold or U-shaped callus in the middle, about 1.6 mm. long.
Column more or less longer than the petals.
Huanuco: Mito, about 2700 meters, on tree trunk, Macbride 3370.
Ecuador (type).
This description was compiled with the aid of a photograph of
the type, in the Ames Herbarium, and a fragment from the type,
sent by Mr. Garay.
Pleurothallis decurrens Poepp. & Endl. Nov. Gen. ac Sp. 1:
48, t. 83. 1836; Lindl. Fol. Orch. Pleurothallis 13, no. 64. 1859; Cogn.
Martius Fl. Bras. 3, pt. 4: 415. 1896. Humboldtia decurrens 0. Ktze.
Rev. Gen. PI. pt. 2: 667. 1891.
Plant stout, medium-sized to large, up to 30 cm. high from the creeping
rhizome to the tip of the leaf. Stems often isolated in pairs, unifoliate, angled and
often quadrangular in the dried specimen, with about 2 close, tubular, evanescent
sheaths on the lower part, up to 25 (rarely 30) cm. long. Leaf erect or spreading,
SCHWEINFURTH: ORCHIDS OF PERU 293
oval or oblong-elliptic (rarely suborbicular), acute or obtuse, minutely cordate
at the base, long-decurrent on the stem, 5-12 cm. long, up to 6 cm. wide. In-
florescences commonly 1 or 2 (sometimes remnants of 5 are present), densely
few-flowered, always shorter than the leaf, erect, rising from the apex of the stem
below the middle of the leaf. Flowers medium-sized, green or yellowish green
often veined with dark green or purplish. Dorsal sepal narrowly oblong-lanceo-
late, acute, 14-18 mm. long. Lateral sepals connate into a lamina which is
subequally long, concave, elliptic-ovate and shortly bidentate at the apex. Petals
about a third to a half as long as the sepals, asymmetrically oblong-oblanceolate,
more or less abruptly acuminate or awned, minutely serrulate above the middle,
with a short keel near the middle of the forward margin. Lip about half as long
as the sepals, oblong-ovate with the lower sides incurved, acute or rounded at the
apex, abruptly cuneate at the base, up to 7.2 mm. long and 4 mm. wide. Column
slender, about equaling the petals, arcuate, abruptly bialate near the apex with
a central triangular, crenulate wing.
Huanuco: Near Cuchero (Cochero) on forest trees, Poeppig 1604
(type). Muna, about 2150 meters, Macbride 4055. Junin: Hua-
capistana, 1800-2400 meters, epiphyte in thickets and open woods,
Killip & Smith 24221. Loreto(?): Rio Huallaga Canon, below Rio
Santo Domingo, about 1230 meters, on tree trunks, Macbride 4252.
Pleurothallis dichotoma (Poepp. & Endl.) Schltr. Fedde Re-
pert. Beih. 9: 140. 1921. Specklinia dichotoma Poepp. & Endl. Nov.
Gen. ac Sp. 1: 52. 1836. = an obscure species, probably not referable
to Pleurothallis.
Huanuco: Near Pampayaco (Pampayacu).
Pleurothallis diffusa Poepp. & Endl. Nov. Gen. ac Sp. 1: 49,
t. 86. 1836; Cogn. Martius Fl. Bras. 3, pt. 4: 397. 1896. Pleurothallis
semipellucida Reichb. f. Linnaea 22: 823. 1849; Lindl. Fol. Orch.
Pleurothallis 7, no. 27. 1859. Humboldtia diffusa 0. Ktze. Rev. Gen.
PI. pt. 2: 667. 1891. Humboldtia semipellucida 0. Ktze. Rev. Gen.
PI. pt. 2: 668. 1891. Pleurothallis com.plicata Rolfe, Mem. Torr. Bot.
Cl. 6: 121. 1896.
Plant very variable, often large, epiphytic or terrestrial, apparently with
a creeping rhizome. Stems solitary or in pairs, slender or stout, monophyllous,
about 10.5-36.5 cm. high, provided with 2 evanescent, tubular sheaths of which
the upper one is elongate and loose. Leaf erect, oblong-ovate or ovate-lanceolate
to elliptic-oblong or elliptic, acute or acuminate, cuneate to rounded at the sessile
base, up to 27 cm. long and 9 cm. wide. Inflorescences 1-7 or more, axillary,
erect or diffuse, slender, more or less surpassing the leaf, about 15 to 40 cm. long,
densely or subdensely many-flowered, issuing from a conduplicate, acuminate
spathe about 2.5-3.5 cm. long. Floral bracts small, inconspicuous, appressed,
infundibuliform. Flowers small or very small, more or less secund, bilabiate,
membranaceous, whitish, greenish or yellow, often dotted with red or purple.
294 FIELDIANA: BOTANY, VOLUME 30
Dorsal sepal lanceolate, oblong-lanceolate or ovate-lanceolate, obtuse to acuminate,
concave, 3.5-6.2 mm. long. Lateral sepals connate, forming a concave-saccate,
broadly ovate, acute to obtuse lamina which is as long as the dorsal sepal but much
broader. Petals a little shorter than the sepals, linear, often more or less clavate-
dilated and thickened above, acuminate (rarely) to obtuse. Lip minute, trans-
verse (i.e., broader than long), abruptly reflexed in the middle, with the broadly
rounded sides erect and the anterior portion semiorbicular with an inflexed
minute apicule (sometimes obscurely trilobed), up to about 1.9 mm. long and much
wider. Column minute, stout, dilated at the base.
Ayacucho: Aina, between Huanta and Rio Apurimac, 750-1000
meters, epiphyte in dense forest, Killip & Smith 22755. Cuzco:
Prov. of Convention, "alturas de Pintobamba," 2700 meters, epi-
phyte, Vargas 3261. Prov. of Quispicanchis, Ttio to Murayaca,
Marcapata, 1960 meters, on rocks, Vargas 3140. San Miguel, Uru-
bamba Valley, about 1800 meters, Cook & Gilbert 908. Huanuco:
Near Cuchero (Cochero), Poeppig s.n. (type of P. diffusa). Cayumba,
near Tingo Maria, 900-1000 meters, Ferreyra 1882. Panao, about
2700 meters, on shrubby slopes, Macbride 3607. Yanano, about 1800
meters, on mossy tree, Macbride 3832. Junin: Chanchamayo Valley,
1500 meters, Schunke s.n. Huacapistana, about 1800 meters, epiphyte
in densely forested valley, Killip & Smith 24294- Huacapistana,
1800-2400 meters, in thickets and open woods, Killip & Smith 24511.
Same data as last, terrestrial, Killip & Smith 24117. Pichis Trail,
Yapas, 1350-1600 meters, epiphyte in dense forest, Killip & Smith
25539. San Martin : Zepelacio near Moyobamba, about 1100 meters,
in mountain forest, Klug 3633. Also Trinidad, Venezuela (type of
P. semipellucida), and Bolivia (type of P. complicata).
The similarity of Pleurothallis diffusa and P. semipellucida was
long suspected; the identity of the two concepts was confirmed by
Mr. Leslie Garay of Toronto, Canada, after he examined typical ma-
terial of P. diffusa from the Reichenbach Herbarium, and this opin-
ion was recently verified by my careful scrutiny.
Pleurothallis diffusa Poepp. & Endl. var. grandiflora (C.
Schweinf.) C. Schweinf. Bot. Mus. Leafl. Harvard Univ. 17: 212.
1956. P. semipellucida Reichb. f. var. grandiflora C. Schweinf. Bot.
Mus. Leafl. Harvard Univ. 15: 102. 1951.
Plant large, epiphytic. Stem stout, suberect, monophyllous, with 2 close,
tubular, evanescent sheaths at the base, about 38.3 cm. high. Leaf spreading,
ovate or oblong-ovate, apparently acute (imperfect at the apex), broadly rounded
or subcordate at the sessile base, about 18.7 cm. long and 8.6 cm. wide. In-
florescences 2, nearly twice as long as the leaf, flexuous-suberect, loosely many-
flowered above, about 33 cm. long. Flowers secund, bilabiate, small but much
larger than those of the type, yellow with spreading segments. Dorsal sepal
SCHWEINFURTH: ORCHIDS OF PERU 295
elliptic-ovate or lanceolate-ovate, acute, about 11 mm. long, concave. Lateral
sepals entirely connate into a suborbicular-ovate, deeply concave, acute lamina
which is about as long as the dorsal sepal but broader. Petals linear, acuminate,
fleshy, lightly incurved, a little shorter than the sepals. Lip very small, transverse,
abruptly reflexed in the middle, lightly 3-lobed, about 2.5 mm. long and 5 mm.
wide when expanded; lateral lobes obliquely semiorbicular; mid-lobe semi-
orbicular-ovate, abruptly acute or mucronate. Column abbreviated, stout,
dilated above and below.
Cuzco: Prov. of Convention, "alturas de Pintobamba," 2700
meters, Vargas 3243.
Pleurothallis diffusa Poepp. & Endl. sensu Lindl. Fol. Orch.
Pleurothallis 3, no. 7. 1859.
Lindley's interpretation is obviously not the P. diffusa of Poepp.
& Endl., since it shows obovate emarginate, instead of linear-lanceo-
late, petals and an apparently dissimilar lip. This concept appears
to be allied to P. Vargasii C. Schweinf.
Pleurothallis dilatata C. Schweinf. Bot. Mus. Leafl. Harvard
Univ. 10: 177, t. 19, figs. 5-9. 1942. Figure 60.
Plant medium-sized, with an ascending rhizome. Stems approximate,
monophyllous, up to 6.5 cm. tall, concealed by 3 tubular, evanescent sheaths.
Leaf elliptic-oblong, rounded at the apex, cuneate at the sessile base, up to 7.5
cm. long and about 1.5 cm. wide. Inflorescences 1 or 2, axillary, suberect, much
exceeding the leaf, up to 13.5 cm. long, loosely racemose nearly to the base.
Floral bracts small, inconspicuous, infundibuliform. Flowers rather small, pale
greenish yellow, with spreading segments. Dorsal sepal oblong-oblanceolate,
obtuse, concave, about 10 mm. long. Lateral sepals falcate-recurved, connate into
an elliptic-ovate, bilobed lamina which is a little shorter than the dorsal sepal but
much broader. Petals much smaller than the sepals, falcate-spatulate, broadly
rounded above. Lip strongly arcuate in natural position, when expanded about
as long as the petals, rather abruptly ovate-dilated in the middle with an oblong
basal and apical portion, rounded above, about 6.5 mm. long and 2.2 mm. wide
near the middle. Column slender, arcuate, shorter than the petals, about 4 mm.
long, with a prominent foot.
Huancavelica: Prov. of Tayacaja, Montepungo, 5 kilometers east
of Surcubamba, 3000 meters, epiphyte on mossy tree trunk, Stork &
Horton 10388 (type in Univ. of Calif.).
Pleurothallis dinotherii Reichb. f. & Warsc. Bonpl. 2: 114.
1854; C. Schweinf. Bot. Mus. Leafl. Harvard Univ. 11: 174. 1944.
Pleurothallis diptera Lindl. Fol. Orch. Pleurothallis 44, no. 279. 1859;
Kranzl. Engler Bot. Jahrb. 54, Beibl. 117, p. 23. 1916. Humboldtia
dinotherii 0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891. Humboldtia
296 FIELDIANA: BOTANY, VOLUME 30
diptera O. Ktze. 1. c. Pleurothallis tricaudata Schltr. Fedde Repert.
Beih. 9: 77. 1921; Mansf. Fedde Repert. Beih. 57: t. 115, nr. 451.
1929.
Plant slender, with an abbreviated rhizome, 15-30 cm. tall. Stems caespitose,
several-jointed, entirely concealed by close, tubular, lepanthiform sheaths with
a somewhat spreading hispid mouth, often with an erect branch above, bearing
several scattered leaves. Leaves shortly petioled, up to 4 cm. long (rarely longer) ;
lamina elliptic to elliptic-oblong, acute or acuminate, cuneate below, up to 3.2
cm. long and 1.2 cm. wide, marginate, with scabrous margins. Inflorescence
solitary, axillary, terminal, filiform, much surpassing the leaf, racemose above,
rarely up to 18 cm. long, laxly few- to many-flowered. Flowers commonly secund,
with spreading or recurved segments, greenish yellow. Dorsal sepal linear-
caudate from a lanceolate concave base, up to 1.75 cm. long. Lateral sepals
similar but slightly narrower at the base, somewhat oblique. Petals many times
shorter than the sepals, obliquely ovate or elliptic-lanceolate, acute to subacute,
with ciliolate margins. Lip somewhat longer than the petals, gently arcuate in
natural position, linear- or oblong-lanceolate (sometimes ovate-oblong), narrowed
to an acute or obtuse apex, cuneate below, with a pair of fleshy lamellae near the
middle and a narrow thickened central line above, about 3.5 mm. or less long.
Column abbreviated, arcuate, about half as long as the petals, with an abrupt,
subquadrate, lobulate wing on each side above.
Peru: Habitat not recorded, Warscewicz s.n, (type). Huanuco:
Prov. of Huanuco, mountains between Chinchao and Acomayo, west
of Huallaga, 3100-3200 meters, in sclerophyllous woods consisting
of shrubs and scattered trees on open grassy places, Weberbauer 6827
(type of P. tricaudata) . Also Ecuador (type of P. diptera) .
I have examined a drawing of P. dinotherii with floral analysis,
from the Reichenbach Herbarium, and a photograph of P. diptera with
floral analysis, from the Lindley Herbarium, in the Ames Herbarium.
Pleurothallis dinotherii Reichb. f. sensu Lindl. Fol. Orch.
Pleurothallis 32, no. 191. 1859.
This concept appears to differ from P. dinotherii Reichb. f. &
Warsc. in having ovate-lanceolate (rather than linear-caudate) sepals
and a rather dissimilar apically rounded lip. It may be referable to
P. dura Lindl.
Pleurothallis divaricans Schltr. Fedde Repert. 10: 387. 1912;
Mansf. Fedde Repert. Beih. 58: t. 30, nr. 120. 1930; C. Schweinf.
Bot. Mus. Leafl. Harvard Univ. 11: 176. 1944.
Plant slender, small to medium-sized, caespitose, up to 17.5 cm. high. Stems
crowded, slender, monophyllous, 3.5-10 cm. long (more or less decumbent at the
base), provided with 2 or 3 close, tubular sheaths of which the uppermost is isolated
and elongate. Leaf erect, elliptic-lanceolate (rarely lanceolate), up to 8.7 cm. long
SCHWEINFURTH: ORCHIDS OF PERU 297
and 1.2 cm. wide, acute to obtuse, cuneate at the commonly sessile base. In-
florescences 1-3, racemose above, diffuse, shorter or longer than the leaf, densely
many-flowered, up to 11 cm. long. Flowers very small, subglobose, bilabiate.
Dorsal sepal suborbicular-ovate, deeply concave, obtuse or acute, up to 2.6 mm.
long. Lateral sepals connate into a broadly obtuse or retuse, deeply concave
lamina which is very similar to the dorsal sepal. Petals slightly more than half as
long as the sepals, cuneate-oblanceolate or oblong-spatulate, acute or subacute
at the broad apex. Lip slightly longer than the petals, broadly rhombic-obovate
with erect-incurved sides, abruptly narrowed above to a triangular acute or
apiculate apex, up to about 1.8 mm. long and subequally wide above. Column
slender, arcuate, a little shorter than the petals.
Junin : Chanchamayo Valley, Rio Blanco, about 1400 meters, on
coffee trees of the Hacienda St. Teresa, Kohler s.n. (type) . Schunke
Hacienda above San Ramon, 1400-1700 meters, epiphyte in dense
forest, flowers greenish white tinged with pink, Killip & Smith 24854-
Chanchamayo Valley, 1200 meters, Schunke 1330. Same locality,
1500 meters, Schunke s.n., 518.
Pleurothallis dura Lindl. Fol. Orch. Pleurothallis 32, no. 192.
1859. Humboldtia dura 0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891.
Plant small, slender, apparently up to 14 cm. tall, caespitose. Stems very
slender, unbranched or often sparingly branched, entirely concealed by close,
lepanthiform sheaths with a spreading hispid mouth, bearing scattered leaves.
Leaves oval to oblong-elliptic, shortly and indistinctly petioled, up to 2 cm. long
and 6.5 mm. wide, acute or obtuse, cuneate below, coriaceous. Inflorescences
commonly solitary, capillary, many times surpassing the leaves, about 3-8 cm.
long, racemose, commonly secund, many-flowered, with more or less elongate,
recurved pedicels. Flowers up to 6 mm. long, perianth ringent. Sepals free,
carinate without. Dorsal sepal ovate-lanceolate, acuminate, deeply concave,
about 3.5 mm. long. Lateral sepals lanceolate, similar to the dorsal sepal but
rather shorter and much narrower. Petals about a third to a half as long as the
dorsal sepal, oblong-oblanceolate, obtuse. Lip longer than the petals, oblong or
ovate-oblong, rounded above, with irregular margins, sulcate or bicarinate through
the lamina, more or less obscurely angled on each side near the middle or base,
about 2 mm. long. Column slightly shorter than the petals, with an apical pair of
falcate, obtuse lateral wings.
Junin: Chanchamayo Valley, Schunke 1158. Ecuador (type).
The Peruvian collection differs from the type, of which we have
seen a record from the Lindley Herbarium, in having usually branched
stems and much shorter racemes, with the pedicels of the apparently
smaller flowers relatively short. The inflorescence, however, seems
to be immature.
Pleurothallis echinocarpa C. Schweinf. Bot. Mus. Leafl. Har-
vard Univ. 10: 179, t. 17, figs. 1-7. 1942. Figure 51.
298 FIELDIANA: BOTANY, VOLUME 30
Plant medium-sized, up to 20 cm. high, with an abbreviated ascending
rhizome. Stems short, stout, approximate, monophyllous, up to 3.5 cm. long,
concealed below by 1 or 2 tubular, evanescent sheaths. Leaf erect, linear-oblong
to narrowly elliptic, up to 11.5 cm. long and 2.1 cm. wide, acute and mucronate,
cuneate at the sessile base. Inflorescence solitary, racemose above, stout, much
surpassing the leaf, up to 16.3 cm. long. Raceme up to 8 cm. long, loosely several-
Cup to 9-) flowered, with a fractiflex rachis. Flowers rather small to medium-
sized, campanulate, secund. Sepals reddish green. Dorsal sepal ovate-lanceolate,
acute, concave, up to 9.8 mm. long. Lateral sepals obliquely ovate-lanceolate or
triangular-lanceolate, acuminate, navicular, a little longer than the dorsal sepal.
Petals much shorter than the sepals, yellow-green, obliquely elliptic-lanceolate,
acute or short-acuminate, with a small tooth on each side near the base. Lip
about equaling the petals, oblanceolate-oblong when viewed from the front, 6-6.4
mm. long, when viewed from the side with a pair of incurved semiorbicular lobules
below the middle separated by a fleshy bilobed thickening, minutely biauriculate
at the base, denticulate at the broadly obtuse apex. Column short, stout, some-
what shorter than the petals. Ovary densely muricate.
Huanuco: Muna, about 2150 meters, in dry woods, Macbride 3969.
Pleurothallis excisa C. Schweinf. Bot. Mus. Leafl. Harvard
Univ.: 16: 48, t. 6. 1953. Figure 52.
Plant rather large, epiphytic, up to about 30 cm. or more tall. Stems approxi-
mate, monophyllous, up to 15 cm. long, provided with 3 or 4 close, tubular sheaths.
Leaf erect, short-petioled, up to 10 cm. long; lamina oblong-elliptic, minutely
apiculate at the obtuse apex, cuneate at the base, up to 9 cm. long and 2.5 cm.
wide. Inflorescences 1 or 2, much surpassing the leaf, densely many-flowered
above, looser below, 17-18.7 cm. long, erect or spreading, arising from a small
conduplicate spathe up to 11 mm. long. Flowers secund, yellow, medium-sized.
Sepals similar, narrow, long-acuminate. Dorsal sepal linear-lanceolate, about
12 mm. long. Lateral sepals lanceolate, very oblique below, about as long as the
dorsal sepal but slightly wider. Petals less than half as long as the sepals, obliquely
oblong, rounded or subtruncate at the apex. Lip slightly larger than the petals,
pandurate-oblong, about 5.6 mm. long; basal half subelliptic, traversed by a pair
of high fleshy keels, the anterior half elliptic-ovate, bidentate at the apex. Column
small, slender, arcuate, prolonged above into a ligulate wing, about 5.5 mm. long
including the wing.
Cuzco: Prov. of Paucartambo, Pillahuata, 3200 meters, epiphytic
in rain-forest, "ceja de montana," Vargas 3006.
FIG. 51. Pleurothallis echinocarpa C. Schweinf. 1, plant; X K- 2, flower
and ovary from side; X 2. 3, lip from above, natural position; X 5. 4, lip from
side, natural position; X 5. 5, dorsal sepal; X 2. 6, lateral sepal; X 2. 7, petal;
X 2. P. brevispicata C. Schweinf. 8, plant; X 1. 9, flower and ovary from side;
X 3. 10, lip from above, expanded; X 5. 11, lip from side, natural position; X 5.
12, dorsal sepal; X 3. 13, lateral sepals; X 3. 14, petal; X 3.
sto
299
FIG. 52. Pleurothallis excisa C. Schweinf. 1, plants; X 1 A> 2, flower,
expanded; X 3. 3, column and lip from side, natural position; X 3.
300
SCHWEINFURTH: ORCHIDS OF PERU 301
Pleurothallis fimbriata Lindl. Fol. Orch. Pleurothallis 17, no. 92.
1859; Cogn. Martius Fl. Bras. 3, pt. 4: 447. 1896. Humboldtia fim-
briata 0. Ktze. Rev. Gen. PL pt. 2: 667. 1891.
Plant small, with a long-creeping rhizome. Secondary stems filiform, mono-
phyllous, commonly 1-2 cm. distant, 4-6.2 cm. long, provided below with 2 close,
tubular, evanescent sheaths. Leaf erect to horizontally spreading, narrowly
elliptic to lanceolate-linear, acute to obtuse, sessile with a cuneate or rounded base,
up to 4.1 cm. long and 9 mm. wide. Inflorescences abbreviated, axillary, 1-
flowered, commonly 2 to 4, much shorter than the leaf. Flower small, bilabiate,
red-brown, or purple and yellow. Dorsal sepal linear or linear-lanceolate, acute
or acuminate, almost twice as long as the lateral sepals, up to 6.9 mm. long.
Lateral sepals connate into a broadly ovate, concave, sharply bidentate lamina.
Petals dwarf, about one third as long as the dorsal sepal, linear-lanceolate to
elliptic-lanceolate, lightly oblique, acute, more or less minutely serrulate above.
Lip somewhat larger than the petals, ovate-oblong when expanded, with semi-
orbicular, incurved lobules below the middle, rounded and denticulate on the
anterior margins, about 2.2 mm. long or less. Column shorter than the petals,
laterally winged throughout, with the apex irregularly denticulate.
Loreto: Gamitanacocha, Rio Mazan, 100-125 meters, epiphyte,
on river bank, Schunke 162. Iquitos, about 100 meters, epiphyte in
woods, Kittip & Smith 26998. Same locality as the last, King 10126.
Also Brazil (type) and British Guiana.
Pleurothallis fimbrilabia C. Schweinf. Bot. Mus. Leafl. Har-
vard Univ. 16: 50. 1953. Restrepia ecuadorensis Rolfe, Kew Bull.
(1892) 138, not Pleurothallis ecuadorensis Schltr.
Plant rather small, epiphytic, with a creeping rhizome. Stems approximate,
slender, about 4-10 cm. high, entirely or mostly concealed by several (up to 7)
sheaths which are loose, tubular, scarious and finely purplish-maculate. Leaf
solitary, erect, oblong-elliptic to oval, obtuse or acute, cuneate at the sessile base,
up to 6 cm. long and 2.9 cm. wide. Inflorescences fascicled, 1 to several, 1-flowered,
issuing from the uppermost sheath just below the leaf, with the pedicel about
5 cm. long. Flowers rather large, membranaceous, bilabiate. Dorsal sepal
linear-lanceolate, about 2.2 cm. long, from an oblong-lanceolate, concave lower
portion gradually narrowed to a filiform apex which is clavate-thickened near the
tip. Lateral sepals connate into an elliptic-oblong, bidentate lamina which is
about as long as the dorsal sepal but more than twice as wide. Petals similar to
the dorsal sepal but much smaller, the lower portion sometimes with a more or
less distinct appressed tooth. Lip about 9 mm. long, abruptly dilated from a small
claw into a suborbicular basal portion provided on each side with a slender,
setiform lobule, then contracted into a linear-oblong, sharply bidentate lamina
which is erose-fimbriate and muriculate through the center. Column slender,
clavate above, about half as long as the lip.
Huanuco: Mufia, about 2100 meters, in dense forest, Macbride
1+018. Ecuador (type of Restrepia ecuadorensis).
302 FIELDIANA: BOTANY, VOLUME 30
Pleurothallis flexuosa (Poepp. & Endl.) Lindl. Bot. Reg. 28,
Misc. 69, no. 7. 1842; Fol. Orch. Pleurothallis 39, no. 239. 1859;
Cogn. Martius Fl. Bras. 3, pt. 4: 491. 1896. Specklinia flexuosa
Poepp. & Endl. Nov. Gen. ac Sp. 1: 52, t. 90. 1836. Humboldtia
flexuosa 0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891. Pleurothallis remoti-
flora C. Schweinf. Am. Orch. Soc. Bull. 21: 108, t., 1952. Fig-
ure 53.
Plant small to medium-sized, epiphytic, caespitose, about 13-30 cm. high.
Stems numerous, slender, more or less abbreviated, monophyllous, up to 5.1 cm.
tall, enclosed by 2 or 3 close, tubular, imbricating, evanescent sheaths. Leaf
erect, elliptic-linear, elliptic-oblong or elliptic-oblanceolate, acute and often
minutely tridenticulate at the tip, gradually narrowed to a sessile base, 5-10.7
cm. long, up to 1.5 cm. wide. Inflorescences solitary or 2 to a stem, filiform, more
or less exceeding the leaf, racemose above, variable in height, up to about 27 cm.
long, suberect to arcuate; raceme remotely 3- to 14-flowered, suberect to arcuate
or flexuous, with a strongly fractiflex rachis. Pedicels elongate and wide-spreading,
up to 1.4 cm. long. Floral bracts minute, infundibuliform. Flowers small,
campanulate, bilabiate, white finely spotted with brownish purple. Sepals long-
pilose within on the upper half, membranaceous. Dorsal sepal more or less
narrowly elliptic-lanceolate, acute or short-acuminate, up to about 9 mm. long.
Lateral sepals connate into a broadly elliptic or suborbicular lamina which is
sharply bidentate above, deeply concave below, nearly as long as the dorsal sepal
and much broader. Petals much shorter than the sepals, obliquely cuneate-
spatulate to semiorbicular-lunate from a short claw, broadly rounded or obtuse-
angled at the apex. Lip subequaling the petals, arcuate-recurved with erect sides
in natural position, about 2.7 mm. long when expanded, distinctly 3-lobed, with
a conspicuous subquadrate claw; lateral lobes semiovate, with a truncate or
subcordate base and adorned with a keel along the outer margin; mid-lobe small,
ovate to oblong-obovate; disc with a large, fleshy, longitudinal callus through the
lower half. Column about as long as the petals, with a large, trilobulate, denticu-
late wing on the upper portion, extended into a prominent foot.
Peru: Habitat not recorded, Mathews 1911. Huanuco: Near
Pampayaco (Pampayacu) and Cuchero (Cochero), epiphyte in for-
est, Poeppig 1515 (type of Specklinia flexuosa). San Martin: Tingo
Maria, along the Huallaga, about 20 km. from Tingo Maria on the
road to Huanuco, 25-1100 meters, Allard 21958. Also Ecuador
(type of P. remotiflora) and Venezuela.
I am indebted to Mr. Leslie A. Garay of Toronto, Canada, for
pointing out that the lip of Specklinia flexuosa (and consequently of
Pleurothallis flexuosa) was incorrectly interpreted both by its original
author and by subsequent workers. As verified by my own observa-
tion, I am convinced that this organ is inseparable from that of
Pleurothallis remotiflora, and that the latter concept must be reduced
to synonymy.
PLEUROTHALLIS
FIG. 53. Pleurothallis remotiflora C. Schweinf . = P. flexuosa (Poepp. & Endl.)
Lindl. 1, plant; X 1 A. 2, flower, expanded, column and lip removed; X 3.
3, lip from above, expanded; X 10. 4, column and lip, oblique view; X 10.
303
304 FIELDIANA: BOTANY, VOLUME 30
Pleurothallis floribunda Poepp. & Endl. Nov. Gen. ac Sp. 1:
48, t. 84. 1836. Pleurothallis macrophylla Lindl. Bot. Reg. 28, Misc.
74, no. 44. 1842; Fol. Orch. Pleurothallis 3, no. 2. 1859, not HBK.
Pleurothallis macrophylla Kunth ex Cogn. Martius Fl. Bras. 3, pt. 4:
396. 1896.
Plant large, 6 dm. or more high. Stems fascicled, very stout, unifoliate.
Leaf erect, distinctly petioled; lamina elliptic-oblong, obtusely acute, cuneate-
narrowed below, up to 30 cm. long and 8.4 cm. wide. Inflorescences fascicled,
numerous, spreading, much shorter than the leaf, densely many-flowered nearly
to the base, 8-15 cm. long, rising from a prominent, saccate spathe up to 2 cm.
long. Flowers small, subdistichous, very short-pedicelled, erect-spreading, sul-
phur-colored. Sepals equally long, free, "oval" or ovate-oblong, acute, about
4-4.5 mm. long, membranaceous, 3-nerved, the lateral ones lightly oblique.
Petals elliptic-oblong, obtuse to subacute, 1-nerved, about half as long as the
sepals. Lip obovate or subelliptic, rounded in the middle, narrowed to both ends,
lightly 3-lobed, triangular-acute, fleshy, about 2 mm. long and 1.6 mm. wide.
Column about half as long as the lip.
Huanuco: Near Pampayaco (Pampayacu) and Cuchero (Cochero),
on trees, Poeppig 1599.
I have examined the type specimen, which does not at all agree
with the description of P. macrophylla HBK.
Pleurothallis fons florum Lindl. Fol. Orch. Pleurothallis 5,
no. 15. 1859. Humboldtia fons florum 0. Ktze. Rev. Gen. PI. pt. 2:
667. 1891.
Plant apparently large (only the upper portion present in the type). Stem
stout, monophyllous. Leaf oval or oblong-elliptic, obtuse to rounded at the apex,
subsessile, about 18 cm. long and 7.6 cm. wide. Inflorescences fascicled, numerous,
racemose, much exceeding the leaf, densely many-flowered almost to the base,
diffuse or flexuous, subtended by a prominent, conduplicate spathe about 3.5 cm.
long. Flowers small, campanulate, about 5 mm. long. Dorsal sepal ovate-
lanceolate, acute, concave. Lateral sepals similar, free. Petals distinctly shorter
than the sepals, broadly oblong, bluntly apiculate at the broad oblique apex.
Lip shorter than the petals, suborbicular-ovate, acute, obscurely 3-lobed above.
Huanuco: Near Cuchero (Cochero), Poeppig s.n. (type). Ecuador.
In the Ames Herbarium there is a photograph with floral analy-
sis of this concept, from the Lindley Herbarium at Kew.
Pleurothallis frutex Schltr. Fedde Repert. 10: 454. 1912.
Plant large, epiphytic, up to 15 dm. tall, variable in all respects. Stems
(presumably approxjmate) much branched with fascicles of short branches at the
nodes, entirely concealed by close, tubular, evanescent sheaths, the branches
being 11.5 cm. or less long. Leaves solitary at the apex of the branches, sessile,
oblong-elliptic to narrowly oblong-lanceolate, subobtuse with a minutely tri-
SCHWEINFURTH: ORCHIDS OF PERU 305
denticulate apex, cuneate at the base, 4-8.7 cm. long, up to 1.5 (rarely 2) cm.
wide. Inflorescences abbreviated, 1-flowered, few to numerous, clustered in the
axils. Flowers medium-sized, campanulate, violet-red, yellow or yellowish-white.
Dorsal sepal oblong-lanceolate, acute to acuminate, or "obtuse," concave below,
10-13 mm. long. Lateral sepals similar to the dorsal sepal but a little smaller,
oblique below. Petals subequaling or slightly surpassing the sepals, narrowly
lanceolate, from a more or less oblique oblong base gradually or rather abruptly
contracted into a long, linear-caudate apex. Lip much smaller than the other
segments, strongly arcuate-recurved below with incurved basal sides in natural
position, oblong or ovate-oblong and 4-5.2 mm. long when expanded, denticulate
above with a rounded apex, rather indistinctly auriculate-dilated near the base;
disc with a pair of more or less distinct, erect, semielliptic calli below or near the
middle. Column minute, stout, broadly winged throughout.
Cuzco: Prov. of Convencion, "alturas de Pintobamba," 2500 me-
ters, perianth yellow, Vargas 3289. Prov. of Paucartambo, Pilla-
huata, 2800 meters, perianth pale yellowish white, Vargas 4954.
Bolivia (type).
Pleurothallis frutex Schltr. var. robusta C. Schweinf. Bot.
Mus. Leafl. Harvard Univ. 15: 91. 1951.
Plant stout, epiphytic, with few, fasciculate, strict branches which are up to
23 cm. long. Leaves similar to those of the type, elliptic-lanceolate to narrowly
oblong-lanceolate, up to 17 cm. long and 2.3 cm. wide. Inflorescences axillary
and glomerate as in the type, many-flowered. Flowers dark brown, with the
segments recurved above. Dorsal sepal lanceolate or oblong-lanceolate, acuminate,
about 1.5 cm. long. Lateral sepals similar to the dorsal sepal but a little shorter,
oblique. Petals similar to those of the type, narrowly lanceolate, long-caudate
above, distinctly longer than the sepals. Lip about 5 mm. long, similar to that
of the type, but differing in having a relatively larger anterior portion and a pair
of prominent teeth rather than obscure auriculate dilations below.
Cuzco: Prov. of Paucartambo, Pillahuata, 3400 meters, rain-forest
in "ceja de montana," Vargas 3007.
Pleurothallis gelida Lindl. Bot. Reg. 27, Misc. 91, no. 186. 1841;
Fol. Orch. Pleurothallis 4, no. 12. 1859; Kranzl. Xen. Orch. 3: 116,
t. 267, fig. II, 8-12. 1893. Humboldtia gelida 0. Ktze. Rev. Gen. PI.
pt. 2: 667. 1891.
Plant commonly large, up to 58 cm. high, with an abbreviated rhizome.
Stems approximate, monophyllous, 5-35 cm. high, provided with 3 or 4 tubular
sheaths of which the uppermost is largest and commonly separated. Leaf erect
or erect-spreading, distinctly short-petioled, up to 25 cm. long; lamina oblong or
oblong-elliptic to oval (rarely slightly broader below or above the middle), obtuse,
cuneate below, 6-21 cm. long, up to 7.1 cm. wide. Inflorescences axillary, race-
mose, 1 to numerous, shorter than to somewhat exceeding the leaf, loosely many-
flowered nearly to the base, up to 25 (rarely 35) cm. long. Flowers small for the
plant, campanulate, greenish white to yellow. Sepals commonly more or less
306 FIELDIANA: BOTANY, VOLUME 30
pilose within above. Dorsal sepal oblong-lanceolate, concave, obtuse to acute,
up to 8 mm. long. Lateral sepals subequally long, oblong-lanceolate or elliptic-
oblong, obtuse to acute, connate below, abruptly saccate at the base. Petals
much shorter than the sepals, obliquely cuneate- or obovate-oblong (rarely
elliptic-lanceolate), acute or truncate and often retuse at the apex. Lip arcuate-
recurved in natural position, slightly shorter than the petals, cuneate or oblong-
cuneate (sometimes pandurate) when expanded, retuse, truncate or broadly
rounded at the apex, bicarinate in the middle, up to 2.5 mm. long. Column
shorter than the expanded lip, arcuate, winged throughout, denticulate above.
Huanuco: Pampayaco (Pampayacu), Kanehira 322.
A wide-spread species extending from Florida through Honduras
to Panama and from the West Indies (type) to Peru.
Pleurothallis genychila Schltr. Fedde Repert. Beih. 9: 74. 1921;
Mansf. Fedde Repert. Beih. 57: t. 114, nr. 446. 1929.
Plant large, erect, epiphytic, about 50 cm. high. Rhizome short, decumbent.
Stems slender, monophyllous, 1-2 cm. distant, up to 35 cm. tall, with 3 close,
distant, tubular sheaths. Leaf suberect or spreading, lanceolate-ligulate, sub-
acuminate, subpetiolate narrowed below, 18-22 cm. long, about 3 cm. wide below
the middle. Inflorescences racemose, fascicled, 3-5, racemose, less than half as
long as the leaf, rather loosely many-flowered, secund. Flowers small, whitish
with blood-red dots, glabrous. Dorsal sepal lanceolate, acuminate with an obtuse
apex, 5 mm. long. Lateral sepals entirely connate into a broadly ovate, cucullate-
concave lamina which is narrowed to an obtuse tip, as long as the dorsal sepal.
Petals obliquely linear, acute, lightly sigmoid, subequaling the sepals in length.
Lip small, from a subquadrate base abruptly dilated and bent down into a 3-lobed
lamina; lateral lobes suborbicular-aliform, incurved in natural position; mid-lobe
orbicular-ovate, "oval," apiculate, with crenulate margins; disc with 2 small,
oblong calli at the base. Column short, footless.
Junin: Mountains of Yanenga, 2300-2400 meters, Weberbauer2125.
Pleurothallis gigantea Lindl. Fol. Orch. Pleurothallis 28, no. 162.
1859. Humboldtia gigantea 0. Ktze. Rev. Gen. PI. pt. 2: 667. 1891.
Plant stout, about 35 cm. high. Stems short, stout, monophyllous, about
4 cm. long, provided with 2 loose, coriaceous sheaths. Leaf oblong, obtuse, sessile
at the cuneate base, up to 15 cm. long and 2.5 cm. wide. Inflorescence solitary,
racemose, stout, about 30 cm. long, loosely several-flowered above the middle,
with a fractiflex rachis. Floral bracts stout, prominent, equitant, incurved,
carinate. Flowers apparently medium-sized. Dorsal sepal ovate-lanceolate or
"ovate-oblong," acute, concave. Lateral sepals uppermost, oblong-lanceolate,
connate up to the middle, wing-carinate, a little longer than the dorsal sepal.
Petals about half as long as the sepals, elliptic-lanceolate, acute, provided with
a pedicellate tubercle at the base in front. Lip slightly longer than the petals,
from a short ligulate claw abruptly 3-lobed; lateral lobes erect, narrowly falcate-
lanceolate; mid-lobe much larger, lanceolate-ovate from a short claw, obtuse, with
a pair of oblong calli at the base of the lamina. Colum 
