Morphology of the Pollinia and Pollinaria of Orchids from Southeast Mexico

2008·22.1 MB·

by  L., Guadalupe Nieto

Selbyana 29(1): 20-68. 2008.
MORPHOLOGY OF THE POLLINIA AND POLLINARIA OF
ORCHIDS FROM SOUTHEAST MEXICO
GUADALUPE NIETO L.
EI Colegio de la Frontera Sur (ECOSUR), Apdo. Postal 36, Carretera Aeropuerto
Antigu.o km 2.5, Tapachula, Chiapas, Mexico
ANNE DAMON*
EI Colegio de la Frontera Sur (ECOSUR), Apdo. Postal 36, Carretera Aeropuerto
Antiguo km 2.5, Tapachula, Chiapas, Mexico
Email: [email protected]
ABSTRACT: This is a report of a morphological study of the pollinaria and pollinia of 91 species of orchids
native to the region of Soconusco in southeast Mexico. A Scanning Electron Microscope (SEM) was used
to obtain details of forms and patterns. The 91 species are divided according to taxonomic groups into 4
sections for ease of management. The flowering dates for each species are presented, and the pollinaria
and pollinia are characterized and compared using the following parameters: number of pollinia per polli
narium; size and shape of the individual pollinia; details of the caudicles (if present); size of stipe (if
present); internal texture of the pollinia; size and form of the tetrads; and finally, the form, superficial exine
layer and internal exine layer, of the surface tetrads. The data and images will be useful for taxonomic
studies, for the identification of pollinaria carried by pollinating insects and birds, and for continuing
research into the mechanisms of orchid pollination.
Key words: epiphytic orchids, terrestrial orchids, orchid pollination, Soconusco
INTRODUCTION sociated with hard pollinia (but see Neowilliam
sia); granular caudicles are mainly composed of
The sexual reproduction of orchids is a highly pollen grains (e.g., Calanthe and Epidendrum);
complex affair involving many different types of and the hyaline caudicles are translucent and
pollinators (usually insects and birds) and a spe elastic with no cells and are composed mainly
cialized structure (the pollinarium) which sticks of elastoviscin, as occurs in the majority of the
to the body of the pollinator and should then, Vandoideae.
theoretically, be transported to the stigma of an Many vandoid orchids, as well as some oth
other orchid flower. However, orchids are well ers, present a band of non-sticky tissue called
known for their low levels of seed set. In reality, the stipe that is derived from rostellum tissue
many flowers never receive that vital visit, and instead of tissue from the anther (Cribb 1999).
even if they do, the pollinarium may never reach The viscidium is a structure composed of part
its destination.
cells and part gum. In the majority of species of
The great majority of orchids present their
Epidendrum, the cells of the viscidium break up
pollen in discrete masses termed pollinia, which,
completely during anthesis and are converted
in turn, are connected by additional structures to
into a gummy substance whose chemical com
the anther. The additional structure may be a
position resembles that of a glucoprotein and is
caudicle or stipe, or in some cases, simply a
secreted to serve as the only source of glue
sticky substance which connects the pollinia to
(Yeung] 987b, Schlee & Ebel 1983).
the viscidium and then unites them to the anther.
The number of pollinia is determined by the
Within each orchid flower, usually 2 or 4 pollin
structure of the anther and number of loculi pres
ia, but sometimes up to 8 or 12 pollinia, and
ent. Many orchids have four pollinia per flower,
their additional structures combine to form a sin
representing four anther cells. In Epidendreae
gle structure, the pollinarium (Cribb 1999).
and Arethuseae, the ancestral number is eight;
A caudicle is usually found in combination
these can have a globular or clavate shape or
with hard and/or compact pollinia. The structure
can be bilaterally flattened. In the su.btribes Lae
of the caudicle may vary; Dressler (1981) divid
liinae and Pleurothallidinae, of the tribe Epiden
ed them into three major groups: bony, granular
dreae, a reduction can be observed from eight to
and hyaline. Bony caudicles are rarely found as-
six to four and finally to two pollinia. Some
members of the Epidendroideae lack septation in
* Corresponding author. the meristematic region of the anther, giving rise
20
NIETO & DAMON: ORCHID POLLINARIA OF SOUTHEAST MEXICO 21
to the development of only two pollinia (Freu visualized by either the transmission electron mi
den stein & Rasmussen 1996). The number of croscope (TEM) or the optical microscope (OM)
pollinia per anther (generally 2, 4, 6 or 8) is (Moore et al. 1991). From the literature, examples
constant at species level and often at genus, sub of the application of SEM to the study of orchid
tribe and tribe levels also. The number of com pollen and pollinia can be seen in the morpholog
pact pollinia per pollinarium is easy to define; ical study of the pollen of Chloraeinae (Orchida
but in the case of mealy pollinia, it can be dif ceae: Diurideae) and related tribes (Ackenuan &
ficult to distinguish between two profoundly Williams 1981), and the revision of the morphol
lobed pollinia and four interconnected pollinia ogy of the subtribe Pleurothallidinae LindL, using
(Dressler 1993). both SEM and TEM (Stenzel 2000).
The unity of pollen grains is maintained by The region of Soconusco is situated in the ex
elastoviscin, a substance derived either from the treme southeast of Mexico, in the state of Chia
tapetum of the anther or from the pollen exine. pas (latitude 16° N; longitude 92° W), on the
All tetrads have an exine layer on the external border with Guatemala. It is a tropical, humid
walL Fitzgerald et al. (1994) studied the evolution region, with seasonal rainfall, rich in biodiver
of the way in which the pollen grains can be sity and with diverse natural and agricultural
packed together to form pollinia with different ecosystems. The region has undergone environ
textures, from the less evolved floury texture, to mental degradation in recent years due to over
hard compact types, and all intermediate stages population and aggressive and inadequate land
from floury to bony. The tetrads of floury pollinia management and now suffers the consequences
separate easily, as seen in Pterostylis (Fitzgerald of severe erosion, flooding and landslides, which
et al. 1994). In the majority of the Spiranthoideae in 1998 and again in 2005 reached crisis point.
and Orchidoideae, as well as the primitive Epi The project "Ecology and Sustainable Cultiva
dendroideae, the pollinia are denominated soft, tion of Native Orchids in Soconusco" is dedi
whereas in the majority of the advanced Epiden cated to the search for mechanisms for the con
droideae the pollinia are hard enough to be servation of native orchids, albeit within re
termed bony. Pacini and Hesse (2002) affirmed stored habitats or within agroecosystems. Re
that the most common type of pollen dispersal search work covers various aspects of orchid
unit (PDU) among the orchid family is the soft ecology, including pollination, which can be a
pollinium, type C, and described a group of pol bottleneck in deteriorated ecosystems where pol
hnia, each consisting of a mass of tetrads joined linators may be scarce or absent and orchid pop
by shared walls, as found in the Spiranthoideae, ulations are small, few, and widely scattered.
Orchidoideae and Epidendroideae. The present study of the morphology of the pol
The wall of an individual, mature, pollen linia of Soconuscan orchids was motivated by
grain is another distinguishing feature, and the the need for a detailed data base to enable us to
formation and structure of these walls have been identify the pollinaria, pollinia, stipes and cau
subject to intensive study. In the Orchidaceae, dicles carried on the bodies of pollinating insects
there are two main variations in the structure of and birds captured during observations and con
the walls: 1) exine is present on the walls of all trolled experiments on pollination.
pollen grains, but only those found on the edge
of the pollinia have a thick and ornamented ex
MATERIALS AND METHODS
ine layer, e.g., Epidendrum scutella and Cata
setum discolor, or 2) the exine layer is present The biological material, consisting of fresh
and well defined only in the external walls of flowers from 91 species of orchids, divided into 4
the tetrads, e.g., Epidendrum ihaguense, Cata taxonomic sections, is shown in TABLE lA, in
setum discolor, Oeceoclades saundersiana and cluding the date and place of collection and the
Loroglossum hircinum (Yeung 1987a, Pacini & accession number. The species studied are listed
Hesse 2002). alphabetically in TABLE lE. The specimens were
In the largest tetrads or pollen units, the indi collected from 1) the field (fragments of tropical
vidual grains can be united by a continuous mem rain forest and traditional coffee plantations); 2)
brane of exine (calymmate) or covered by an in native orchids collected from various localities in
dividual exine layer (acalymmate), which is gen Soconusco and maintained in the Regional Botan
erally reduced on the internal face, making it pos ical Garden "El Soconusco" (municipality of Tuz
sible to distinguish the arrangement of the tetrad antan, Chiapas; altitude 80m; 15°07'03"N;
(Faegri & Iversen 1989, Konta & Tsuji 1982). 92°24'53'W) and its annex, Orchidarium "Santo
Although the scanning electron microscope Domingo" (municipality of Union Juarez, Chia
(SEM) is not the traditional method for the study pas; altitude 900 m; l5°0l'48''N; 92°06'21'W); and
of pollen morphology, it offers particularly valu 3) from rustic and sustainable orchid cultures in
able details of fonus and patterns that cannot be rural communities in the Soconusco region, which
22 SELBYANA Volume 29(1) 2008
TABLE L List of orchid species studied, with collection data.
Section 1: 1
Accession
Collection number
Species Flowering date site (voucher)
Subfamily Orchidoideae
Tribe Cranichideae
Subtribe Spiranthinae
Aulosepalum hemichreum (Lind!,) Garay. 28 January 2004 and SD 54
23 January 2005
Sarcoglottis sp. X 2 19 March 2005 JB 332,
331
Sarcoglottis sceptrodes (Rchb.f.) Schltr. 6 February 2004 JB 339
Subfamily Epidendroideae
Tribe Sobralieae
Elleanthus cynarocephalus (Rchb.f.) Rchb.f. 28 August 2005 SD 397
Sobralia macrantha Lind!. 18 May 2005 LP 220
Subtribe Bletiinae
Coelia macrostachya Lindl. 20 September 2005 SD 436
Tribe Epidendreae
Subtribe Ponerinae
lsochilus carnosiflorus Lind!. 4 May 2004 and 2 SD III
May 2005
lmchilus aff. latibracteatus A. Rich & Galeotti 2 May 2005 SD 113
lsochilus aff. linearis (Jacq) R. Br. Data lost 501
Isochilus aff. major Cham. & Schltr. 25 May 2005 SD 261
Isochilus sp. 6 August 2004 SD 282
Nemaconia striata (Lind!.) van der Berg. 26 January 2005 SD 208
Section 1: 2
Collection
Species Flowering date site Voucher
Tribe Epidendreae
Subtribe Laeliinae
Barkeria obovata (c. Pres!.) Christenson 7 January 2004 and 3 JB 378
January 2005
Barkeria skinneri (Bateman ex Lind!.) A. Rich & Gal- 542
eotti
Brassavola nodosa (L.) Lind!. 7 January 2004 and 9 JB 2
July 2004
Caularthron bilamellatum (Rchb.f.) R.E. Schultes 22 February 2005 GUA 484
Encyclia adenocarpa (La Llave & Lex.) Schltr. 29 April 2004 JB 60
Encyclia parviflora (Regel) Withner 19 March 2004 and 9 JB 59
March 2005
Encyclia cordigera (Kunth) Dressler 5 March 2004 and 9 SD 73
March 2005
Encyclia selligera (LindJ.) Schltr. 24 February 2004 SD 453
Encyclia bractescens (Lindl.) Hoehne 17 March 2005 PP 465
Epidendrum ciliare L. 7 July 2004 and 10 SD 403
July 2005
Epidendrum lacertinum Lind!. 11 May 2004 SD 343
Epidendrum melistagum, Hagsater 5 July 2005 PP 90
Epidendrum polyanthum Lind!. 10 August 2004 SD 319
Epidendrum stamfordianum Bateman 30 October 2003 SD 94
Epidendrum ramosum Jacq. 6 August 2004 and 7 SR and 104
October 2004 SD
Guarianthe aurantiaca (Bateman ex Lind!.) Dressler & 28 January 2004 and SD 31
w.E. Higgins 11 January 2005
Guarianthe skinneri (Bateman) Dressler & W.E. Higgins 20 January 2004 and JB and 37
11 January 2005 SD
Jacquiniella cobanensis (Ames & Schltr.) Dressler 28 March 2004 SD 317
NIETO & DAMON: ORCHID POLLINARIA OF SOUTHEAST MEXICO 23
TABLE 1. Continued.
Section 1: 2 continued
Accession
Collection nUlnber
Species Flowering date site (voucher)
Laelia rubescens LindL 3 December 2004 and SD 396
30 November 2005
Meiracyllium trinasutum Rchb.f. 4 March 2004 and 8 SD and 136
April 2005 EPBD
Nageliella purpurea (LindL) L.O. Williams 1 July 2004 Y 146
Nidema boothii (Lind!.) Schltr. 23 March 2004 and 15 SR 155
April 2005
Prosthechea baculus (Rchb.f.) W.E. Higgins 23 March 2004 and 9 SD 57
March 2005
Prosthechea chacaoensis (Rchb.f.) W.E. Higgins 10 February 2005 and SD 66
9 March 2005
Prosthechea chondylobulbon (A. Rich & Ga1eotti) W.E. 17 March 2005 PP 449
Higgins
Prosthechea cochleata (L.) \VE. Higgins 7 July 2004 and 5 July SD and 384
2005 PP
Prosthechea livida (LindL) W.E. Higgins 8 August 2005 SD 382
Prosthechea ochracea (LindJ.) W.E. Higgins 10 August 2004 and SD 78
13 December 2004
Prosthechea radiata (LindL) W.E. Higgins 25 June 2004 and 9 SR 386
July 2004
Scaphyglottis crurigera (Bateman ex LindL) Ames & 23 March 2004 and 8 SD 214
Correll March 2005
Scaphyglottis sp. 23 October 2005 TG 534
Section I: 3
Collection
Species Flowering date site Voucher
Tribe Epidendreae
Subtribe Pleurothallidinae
Platystele ovatilabia (Ames & C. Schweinf.) Garay 5 March 2005 SD 354
Pleurothallis sp. 1 14 and 17 March 2005 PP 370
Pleurothallis sp.2 27 October 2005 LP 357
Specklinia lateritia (Rchb.f.) Pridgeon & M.W. Chase 10 August 2004 SR 381
Specklinia marginata (LindL) Pridgeon & M. W. Chase 19 March 2004 and 8 EPBD 352
April 2005
Specklinia tribuloides (Sw.) Pridgeon & M.W. Chase 13 December 2004 SD 197
Stelis quadrifida (La Llave & Lex.) Solano & Soto Are- 13 December 2004 and SD 195
nas 30 November 2005
Stelis sp. 5 March 2005 SD 235
Trichosalpinx blaisdellii (S. Watson) Luer 10 October 2004 and SD 243
28 August 2005
Tribe Cymbidiae
Subtribe Oncidiinae
Brassia verrucosa Lindley 4 May 2004 and 2 LP 435
May 2005
Cuitlauzina convallarioides (Schltr.) Dressler & N. H. 26 January 2005 and 5 SD 439
Williams March 2005
Erycina crista-galli (Rchb.f.) N.H. Williams & M.W. 5 November 2003 and SD 299
Chase 30 August 2005
lonopsis satyrioides Reichb.f. 17 March 2005 COB- 536
ACH
Leoehilus labiatus (Sw.) Kuntze 30 November 2005 SD 321
Leochilus oneidioides Knowles & Westc. 30 November 2003 SD 335
Leochilus scriptus (Sw.) Rchb.f. 5 January 2005 JB 398
Leochilus aff. labiatus. Purp1e-leaved* 20 January 2004 and JB 323
15 January 2005
Lockhartia verrucosa LindL ex Rchb.f. 30 November 2005 SD 254
24 SELBYANA Volume 29(1) 2008
TABLE 1. Continued.
Section 1: 3 continued
Accession
Collection number
Species Flowering date site (voucher)
Notylia barkeri Lindl. 7 January 2004 SD 362
Oncidium laeve (Lindl.) Beer 29 April 2004 and 14 SR 499
April 2005
Oncidium ornithorrhynchum Kunth 5 March 2004 SD 356
Oncidium sphacelatum Lindl. 5 March 2004 JB 176
Ornithocephalus tripterus Schltr. 8 July 2004 and 28 SD B
August 2005
Trichocentrum ascendens (Lindl.) M.W. Chase & N.H. 5 January 2005 JB 160
Williams
Trichocentrum candidum Lindl. 2 December 2003 SD 259
Trichocentrum microchilum (Bateman ex Lindl.) M.W 10 August 2004 SN 400
Chase & N.H. Williams
Trichocentrum oerstedii (Rchb.f.) R. Jimenez & Came 20 January 2004 SD 305
valii
Trichopilia tortilis Lindl. 8 March 2005 SD 385
Section 1: 4
Collection
Species Flowering date site Voucher
Subfamily Cymbidiae
Tribe Catesinae
Catasetum integerrimum Hook 4 May 2004 and 28 JB 22
September 2005
Cycnoches egertonianum Bateman o August 2005 SRI C
Cycnoches ventricosum Bateman 25 June 2004 and 10 SRI 44
August 2005
Mormodes lineata Bateman ex Lindl. 5 November 2003 and SD and 138
3 January 2005 JB
Tribe Eulophiinae
Oeceoclades maculata (Lindl.) Lindl. * 28 August 2005 SRI 498
Tribe Maxillariinae
Maxillaria parviflora (Poepp. & Endl.) Garay 10 October 2004 and SD 255
28 August 2005
Maxillaria densa Lindl. 5 January 2005 SD 130
Maxillaria aff. elatior (Rchb.f.) Rchb.f. 8 March 2005 SD D
Maxillaria friedrichsthalii Rchb.f. 23 March 2004 and 9 SD 133
March 2005
Maxillaria hagsateriana Soto Arenas 5 September 2005 SD 288
Maxillaria ringens Rchb.f. 6 July 2005 SR 452
Maxillaria variabilis Bateman ex. Lindl. 30 November 2005 SD 127
Mormolyca ringens (Lindl.) Schltr. 5 November 2003 and SD and 145
30 November 2005 JB
Trigonidium ergotonianum Bateman ex Lindl. 6 April 2004 JB 479
Tribe Stanhopeinae
Gongora galeata (Lindl.) Rchb.f. 7 July 2004 and 7 July LP 98
2005
Stanhopea saccata Bateman 7 July 2004 SD 229
Tribe Zygopetilinae
Kefersteinia tinschertiana (Pupulin) 8 July 2005 LP E
Subfamily Vandeae
Tribe Polystachyinae
Polystachya foliosa (Hook) Rchb.f. 2 September 2004 SD 183
Tribe Angraecinae
Campylocentrum micranthrum (Lindl.) Rolfe 8 April 2005 EPBD 265
All accession numbers are prefixed by JBSOC-ECOSUR-TAP-MEX.
NIETO & DAMON: ORCHID POLLINARIA OF SOUTHEAST MEXICO 25
are managed by the project "Ecology and sustain a) The pollinia were left to soak in distilled wa
able cultivation of native orchids" of the Biodi ter for 30-60 min. until completely hydrated,
versity Conservation Dept. of ECOSUR, Tapachu indicated by color and loss of transparency,
lao Under these conditions it was not possible to after which they were soaked for 30 min. in
estimate the age of the flower, and it is possible a series of ethanol solutions at 30, 50, 70, 90
that some pollinaria were older and more dehy and 100% (two changes at 100%) and finally
drated than others at the time of collection. Date dried at the critical point of CO2,
and place of collection of all plants are recorded b) The dry pollinia were mounted, as before, on
in a data base. the aluminum stub and then covered in a layer
We studied many more specimens of pollinia of gold-palladium, to a depth of approximately
than are presented here, but have only included 20 nm, using a Denton Vacuum Desk n.
those that can be supported by photographs of c) Observations were carried out using the
the flowers and live specimens of the plants SEM, under high vacuum, 10-15 kY. An im
maintained in the Regional Botanic Garden HEI age was taken of the fully processed com
Soconusco." All plants are referenced by acces plete pollinarium and a close up of the sur
sion numbers maintained in a data base. face of the exine layer of one of the pollinia.
A total of 91 species from 48 genera were d) The mounted samples were fractured using
included in this study, of which 79 were fully fine tweezers and pins, and the newly ex
identified. Flowers were placed into inflated, posed surface was covered with gold-palla
sealed plastic bags with details of plant species, dium for observation of the surface of the
date and locality, and transported to the labora section, the internal texture of the pollinia, as
tory in ECOSUR in Tapachula. This study was well as a close up of the tetrads and the exine
carried out using the best single sample of a pol layer of the internal walls of the tetrads on
linarium for each species; and where there was the surface.
a second flowering during the study period, a
With the program for the acquiring and pro
second sample was taken to confirm the char
cessing of images, Orion 6.5, of the SEM Top
acteristics noted.
con SM 510, the length and width of the indi
The classification applied in this study is that of
vidual pollinia were measured, both in the fresh
Chase et al. (2003). The taxonomy of a few of the
and processed state (rehydrated and dried to the
genera is confused. In the case of Isochilus, al critical point of CO2),
though 1. aurantiacus is clearly distinguishable, di The number of pollinia per pollinarium was
visions between the other species listed for the So described, as well as the shape and form of the
conusco region, 1. canwsiflorus, 1. latibracteatus, individual pollinium, using as a reference the
1. linearis and I major, are not so clear. The dif terminology for symmetrical figures (SACDT
ferent samples of pollinia collected from the var 1962, Stearn 1966) and examples from Freuden
ious Isochilus in the area showed notable differ stein and Rasmussen (1996), Stenzel (2000), and
ences which were not obvious from the flowers. Singer and Koehler (2004).
These specimens, tentatively named I camosiflo The texture of the pollinium was described
rus, I aff. latibracteatus, I aff. linearis, 1. aff. ma after dry fracture and then classified according
jor, and one sample that did not coincide with any to the grade of compaction, in agreement with
of these (I sp.), are included in this study and may criteria established in the literature (Dressler
prove to be useful for future studies of this genus. 1993, Pacini & Hesse 2002, Hesse et al' 1989,
Stelis is another confusing genus, and only two of cited by Fitzgerald et al. 1994).
the various species found in the Soconusco region The tetrads on the inside of the pollinia were
are included in this study: one, identified to genus measured (length and width) and the arrange
level only; and one species, currently known as S. ment of the pollen grains within it were de
quadrifida, which has a confused taxonomic his scribed according to the literature (Yeung 1987a,
tory (Solano & Soto Arenas 2003a and b). Ackerman & Williams 1981, Stenzel 2000, Fae
The pollinarium was extracted from each gri & Iversen 1989). The size of the tetrads pre
fresh flower and mounted upon an aluminum sented is an average of the measurements of 10
stub held in place with conductive carbon tape to 15 tetrads taken from the same pollinium, us
with double sided adhesive. Observations were ing images augmented 2000 times.
carried out under conditions of low vacuum us The ornamentation of the exine layer of the
ing a SEM Topcon SM 510, at 25-30 kV and external and internal walls of the tetrads on the
0.1-0.2 mtorr. An image was recorded of the surface, and the arrangement of the tetrads was
fresh pollinarium. Individual pollinia were taken described, using as a reference the Manual of
from each pollinarium and processed in the fol Pollen Terminology presented in the Paldat web
lowing manner: site (Buchner & Weber 2000); table of exine
26 SELBYANA Volume 29(1) 2008
classification, with examples from Moore et al. fractured-in only a few cases was it possible
(1991); and the palynology glossary (http:// to determine the arrangement of the pollen
www.bio.uu.nl/~palaeo/glossary/glos-lit.htm). grains within the tetrads; C. Hard 2 (compact
For well represented groups, a summary of hard texture, type 2), for pollinia that do not
pollinaria and pollinia characteristics is given. fracture easily and the walls of the pollen grains
within the tetrads almost always break. A thicker
wall joining the individual pollen grains may be
Presentation of Results
observed. It was not possible to determine the
The results of the measurements and the mor arrangement of the tetrads in this category.
phological characterization of the pollinia of the Some of the pollinia in all categories had col
91 species studied are presented as four taxo lapsed tetrads, and it was not possible to deter
nomic sections. For each section, the data are mine their texture.
presented in TABLES 2: 1-4 as foHows:
Size of tetrad. Measurements of the length
(R) Indicates that two specimens were studied, and width of the tetrads were taken from images
either from different plants or from the same at 2000X and are presented in microns. The size
plant in different years. reported is the average of the measurements
made of 10 to 15 interior tetrads from the same
Number of poHinia (per pollinarium). Where
pollinarium.
the pollen masses presented different sizes, this
is indicated by ''1'' for large and "s" for small. Shape of tetrad. The arrangement of pollen
grains towards the interior of the tetrads is de
Size of pollina. Measured in millimeters and
scribed. Where two different arrangements were
represented the length and width of the pollini
observed for the same species, the first men
um. Measurements were made from the SEM
tioned is the most frequent. The term calymmate
images of both fresh and processed pollinia. The
refers to those tetrads in which the pollen grains
number of measurements made depended upon
share a common covering of exine. It was not
the number of individual pollinium per pollinar
possible to determine the arrangement of pollin
ium (2, 4, 6, 8) and an average of pollinia size
ia with hard texture #2, and images of the tetrads
in each state was calculated. Size reported
for these species are not included.
(width and length) in TABLE 2 is an average val
ue of both states. This result is obviously an ap Surface tetrads. The tetrads at the surface of
proximation and was further influenced by the the pollinia are described as isometric when they
orientation of the image of the sample from have the same arrangement as the tetrads to
which the measurements were taken. wards the interior of the pollinia, with no elon
gation. "Slightly elongated" refers to surface
Shape of pollinia. The shape of each pollin
tetrads that are linear and slightly stretched in
ium was noted, using the terminology for sym
comparison with interior tetrads. Elongated tet
metrical figures (SACDT 1962 and Stearn
rads are approximately twice as long as wide.
1966). Additional notes are presented if there is
These arrangements can be observed at 1000X
asymmetry on one side or face of the pollinia,
when the pollinia are fractured and include an
or if the form is irregular.
edge and part of the interior.
Caudide. The texture and presentation of the
Surface exine layer. The main ornamentation
caudicles are described. Empty spaces in the table
of the exine layer of the external walls of the
indicate that the pollinia do not have a caudicle.
surface tetrads is described. This parameter can
Size of stipe. Averages of the length and the be appreciated at 5000 X .
widest part of the stipe are presented in milli
meters. Empty spaces in the table indicate that Interior exine layer. The ornamentation of
the exine layer of the internal walls of the sur
the pollinia do not present a stipe.
face tetrads is described. This parameter can be
Texture. This is an appreciation of the image appreciated at 5000 X .
at 1000X of the pollinium, taken after the trans
verse cut was made. The following descriptions Flowering date. The date on which the flower
were applied: Floury, for low level of compac was collected is recorded.
tion with both the exterior and the interior tet
Collection Site
rads having an exine layer; C. Soft (compact
soft), for pollinia that disintegrate easily when COBACH: Coffee plantation belonging to
fractured, the tetrads and their arrangement are COBACH school, Santo Domingo,
easy to see; C. Hard 1 (compact hard texture, Municipality of Uni6n Juarez,
type 1), for pollinia that have entire tetrads when Chiapas.
TABLE 2:l. Morphological and morphometric characteristics of the pollinia and tetrads of the orchid species studied in section 1.
Size of pollinia (rom) Size of tetrad
No. Shape of ([Lm) length Shape of Surface Surface exine Interior exine
Orchid species pollinia Length Width pollinia Caudicle Texture' X width tetrad tetrads layer layer
Coelia macrostachya 4 0.60 0.56 triangular, del- granular, hya- c. soft 28.9 X slightly rhomboid, fossulate fossulate ~
toid line mass 20.0 elongat- tetrahe- ~
holding all ed dral 0
pollinia to- R<>
gether ti
Deiregyne hemichreaR 4 3.62 0.82 cuneate n.p." floury 35.8 X 27.3 elongated rhomboid reticulate reticulate ~
Elleanthus cyanaroce- 8 0.90 0.45 elliptical, ir- granular, long, c. hard 1 24.8 X 19.7 isometric calymmate fossulate fossulate
phalus regular 4 fused cau- 0
dicles ~
Isochilus carnosiflorusR 4 0.67 0.29 elliptical granular, long, c. hard 1 18.5 X 13.5 slightly calymmate scabrate to laevigate to
~
4 fused cau- elongat- laevigate rugose
dicles ed =:
.....
Isochilus aff. latibrac- 4 0.51 0.26 elliptical to granular, long, c. hard 2 n.d.b isometric n.d.b scabrate to laevigate to ti
teatus oblong 2 fused cau- laevigate rugose
"tl
dicles
~
Isochilus aff. linearis 4 0.52 0.21 elliptical granular, long, c. hard 2 n.d.b isometric n.d.b scabrate gemmate
4 fused cau-
dicles ~
Isochilus aff. major 4 0.60 0.26 elliptical granular, long, c. hard 1 20.6 X 17.1 slightly calymmate laevigate to laevigate to
4 fused cau- elongat- rugose rugose >
dicles ed
0
Isochilus sp. 4 0.52 0.26 clavate, flat- granular, long, c. hard 2 n.d.b isometric n.d.b laevigate laevigate "Ti
tened 4 fused cau- Cfl
dicles 0
Sarcoglottis sp. 1 4 3.52 0.56 cuneate, open n.p." floury 34.4 X 26.8 elongated rhomboid reticulate reticulate ~
in center
Sarcoglottis sp. 2 4 3.82 0.55 cuneate, open n.p." floury 37.5 X 26.7 elongated rhomboid reticulate reticulate t>rI
in center Cfl
Ponera striata 4 0.73 0.56 elliptical to granular, long, c. soft 18.2 X 13.7 slightly rhomboid, laevigate to laevigate to ~
oblong, 2 fused caudi- elongat- tetrahe- rugose rugose ~
wide cles ed dral .~...
Sarcoglottis sceptrodes 4 5.31 0.76 cuneate, open n.p." floury 42.1 X 36.5 elongated rhomboid reticulate reticulate n
in center 0
Sobralia macrantha 4 2.10 0.67 irregular n.p." floury 26.5 X 21.3 isometric tetrahedral, verrucate verrucate
rhom-
boid
R Average of two repetitions; "not present; b not determined; 'c: compact. N
-.J
TABLE 2:2. Morphological and morphometric characteristics of the pollinia and tetrads of the orchid species studied in section 2. 0N0
Size of pollinia Size of
(mm) tetrad (fLn) Surface Interior
No. Shape of length Shape of Surface exine exine
Orchid species pollinia Length Width pollinia Caudicle Texturee X width tetrad tetrads layer layer
Barkeria obovataR 4 0.36 0.31 almost spheri- granular, long, c. soft 21.1 X tetrahedral elongated laevigate scabrate
cal, flattened 2 fused cau- 13.5
dicles
Barkeria skinneri 4 0.80 0.63 obovate, wide, granular, long, c. soft 24.5 X calymmate slightly laevigate to scabrate
flattened simple 19.24 elongat- rugose
ed
Brassavola nodosaR 4 la 1.10 0.52 obovate with 4 granular, c. soft 2l.4 X tetrahedral slightly laevigate scabrate
4 Sh 0.70 0.39 one straight long, simple 16.4 elongat-
(+8 side caudicules ed
mini) with one
pollinia at
each ex-
treme
(.fJ
Caularthron 4 1.19 0.82 elliptical, ir- granular, long, c. soft 17.8 X rhomboid elongated laevigate scabrate tTl
bilamellatum regular, flat- 2 fused cau- 16.0 lto'
tened dicles >>-<-
Encyclia adenocmpa 4 0.87 0.55 obovate, flat- granular, long, c. hard 1 16.7 X rhomboid, elongated laevigate scabrate
tened simple 12.9 tetrahe- Z>-
dral
Encyclia parvijloraR 4 0.98 0.68 obovate, flat- granular, long, c. hard 1 18.5 X rhomboid, elongated laevigate to scabrate
tened simple 15.4 square scabrate
Encyclia cordigeraR 4 l.78 0.95 obovate, flat- granular, long, c. hard 1 17.4 X rhomboid elongated laevigate scabrate
tened simple 14.3
Encyclia selligera 4 1.02 0.54 obovate, flat- granular, long, collapsed n.d.d collapsed slightly laevigate scabrate
tened simple elongat-
ed
Encyclia bractescens 4 1.16 0.81 obovate, flat- granular, long, c. soft 16.5 X rhomboid, isometric laevigate to scabrate
tened simple 13.7 tetrahe- scabrate
dral -<
Epidendrum ciliare" 4 1.12 0.98 lingulate granular, long, c. hard 1 2l.3 X rhomboid, slightly laevigate to scabrate
2 fused cau- 16.8 square elongat- scabrate ~
dicles ed S
Epidendrum 4 1.17 0.77 lingulate granular, long, c. hard 1 25.0 X rhomboid slightly laevigate scabrate (p
N
lacertinum 2 fused cau- 17.3 elongat- ~
dicles ed '""'
'-'
N
0
0
00
TABLE 2:2. Continued.
Size of pollinia Size of
(mm) tetrad (ILn) Surface Interior
No. Shape of length Shape of Surface exine exine
Orchid species pollinia Length Width pollinia Caudicle Texture' X width tetrad tetrads layer layer ~
Epidendrum 4 0.81 0.64 obovate, wide, granular, long, c. hard 1 19.2 X ca1ymmate slightly scabrate to gemmate >-l
melistagum flattened 2 fused cau- 15.2 elongat- laevigate 0
dicles ed ??
Epidendrum 4 0.59 0.36 elliptical to granular, long, c. hard 2 n.d.d n.d.d slightly scabrate to scabrate t;I
polyanthum oblong 2 fused cau- elongat- laevigate
~
dides ed
Epidendrum 2 la 0.98 0.39 falcate, with granular, long, c. hard 1 14.7 X calymmate isometric scabrate to scabrate 0
stamfordianum 2 Sb 0.84 0.32 one straight 4 fused cau- 11.1 laevigate ~
side dicles 0
Epidendrum ramosumR 4 0.36 0.18 elliptical, flat- granular, hya- c. hard 2 n.d.d n.d.d isometric laevigate gemmate ~
tened line, long, 2 0::
fused caudi- ......
t;I
des
'"0
Guarianthe aurantiacaR 4 0.92 0.64 obovate, flat- granular, long, c. soft 15.1 X tetrahedral, elongated scabrate to scabrate 0
tened simple 12.8 rhom- laevigate b
boid
Guarianthe skinneriR 4 1.01 0.62 obovate, flat- granular, long, c. soft 16.9 X rhomboid elongated laevigate to scabrate ~
tened simple 12.1 scabrate
JacquinieUa cobanensis 2 0.54 0.30 elliptical to very short c. hard 1 12.1 X calymmate isometric laevigate to laevigate to >
oblong 10.1 scabrate rugose
0
Laelia rubescensR 41a 0.69 0.59 elliptical to granular, long, c. soft 15.2 X tetrahedral slightly scabrate to scabrate '!j
4 Sb 0.57 0.47 oblong, simple, with 14.3 elongat- laevigate en
wide a pollinia at ed 0
C
each ex-
treme ~
Meiracycllium 41a 0.86 0.24 clavate e1on- granular, long, c. soft 14.4 X calymmate isometric laevigate scabrate >tIl
trinasatumR 4 Sb 0.50 0.27 gated and 2 fused cau- 11.8 en
falcate, with dic1es >-l
one straight ~
side ~
Nageliella purpurea 4 0.64 0.34 elliptical, ir- granular, hya- c. hard 2 n.d.d n.d.d elongated laevigate laevigate ......
n
regular line, long, 2
0
fused caudi-
des
Nidemia boothiiR 4 0.64 0.44 obovate, flat- granular, long, c. soft 17.6 X calymrnate slightly laevigate scabrate
tened 2 fused cau- 13.7 elongat-
dic1es ed N
\0