Peristomal ornamentation, a precise character for discrimination of Ulota bruchii and U. crispa (Bryopsida, Orthotrichaceae)

Journal of Bryology (2000) 22: 273-278

Peristomal ornamentation, a precise character for discrimination of

Ulota bruchii and U. crispa (Bryopsida, Orthotrichaceae) R. GARILLETI1, F. LARA2, B. ALBERTOS2 and V. MAZIMPAKA2 ^niversidad Europea de Madrid and 2Universidad Autonoma de Madrid, Spain

Summary

A comparative study of structure and ornamentation of Ulota bruchii and U. crispa peristomes is reported. New peristomial characters and those previously suggested are recorded and discussed, and

characters enabling an accurate discrimination of the taxa are proposed. Among them, the endostome structure and ornamentation are the characters that afford the most accurate discrimination.

KEYWORDS: peristome, moss taxonomy, Europe, Spain, Portugal, Ulota crispa, U. bruchii.

Introduction

together with that of the capsule form. This study showed that, for taxa discrimination, the characters proposed by

The discrimination of Ulota crispa (Hedw.) Brid. and

Rosman-Hartog & Touw (1987) were more suitable than

U. bruchii Brid. has been traditionally based on two main

the capsule form, because of the small number of intermedi

characters: leaves more strongly twisted in U. crispa than in

ates. However, the excellent light microscope micrographs

U. bruchii and capsule more contracted beneath the mouth

that illustrate the paper by Smith & Proctor (1993, Figs 9-

(like an amphora) in U. crispa and fusiform in U. bruchii.

16) show that the areolation is not always easy to interpret

However, the variability of these characters makes the

and, thus, some specimens may be difficult to identify. As

identification of numerous specimens having intermediate

for the PPL ornamentation, Smith & Proctor (1993) agree

forms almost impossible. The apparently poor definition of

with its unequivocal nature when observed by SEM and

morphological differences between the two taxa has led

with its use (though not easy) when using the light micro

several authors to reduce one of them to subspecific rank.

scope.

Thus, Smith & Hill (1975) suggested a varietal rank for

Hartog in the practical difficulty of this character. One of

U. bruchii, under the trinomen Ulota crispa var. norvegica

the conclusions of this study was that, for a number of

However,

these

authors

agreed

with

Rosman-

(Gronv.) Smith & Hill. Other authors, however, have

specimens, separate use of the different characters leads to

preserved the specific category for this plant and searched

contradictory identifications, which is a potential source of

for new qualitative characters affording its discrimination

misidentifications of these taxa. Finally, Smith & Proctor

from U. crispa. Thus, Rosman-Hartog & Touw (1987)

(1993) concluded that, even using together all the charac

proposed the first character allowing a safe separation of

ters known today, a small percentage of specimens will

the taxa: the areolation of the capsule mouth. According to

always remain unidentifiable.

these authors, the differentiated cells that form the exothecial bands reach the capsule mouth in U. bruchii, while in

This controversy and the confusion that has character ized the chorological delimitation of these two mosses in

U. crispa, they are interrupted by a continuous ring of

Spain (Albertos et al, 1999) led us to carry out a new criti

ovate or isodiametric cells that surrounds the capsule

cal study, aimed at assessing complementary qualitative

mouth (Figs 1 and 2). Rosman-Hartog & Touw (1987) also

characters that could afford an easy and safe discrimina

found differences in the ornamentation of the internal side

tion of Ulota crispa and U. bruchii.

of the exostome (PPL), but remarked that 'some structures observed are hardly or not at all visible with the light

microscope', which suggested that this character was of

Materials and Methods

little use for the identification of the two mosses. After

The experience accumulated in the last few years on the

wards, Smith & Proctor (1993) evaluated both characters

importance of the structure and ornamentation of the

© British Bryological Society 2000

Received 7 December 1999. Revision accepted 21 February 2000

274

Figures 1 and 2.

R. GARILLETI ET AL.

Areolation of the capsule mouth in Ulota bruchii and U. crispa. 1. U. bruchii. 2. U. crispa.

peristome in the discrimination of species of the genus

31-03-1996; Cangas de Narcea, Laron, 950 m, 29TPH9464,

Orthotrichum Hedw., the most closely-related genus to

sobre Q. pyrenaica, Albertos, Garilleti, Lara & Mazimpaka,

Ulota Brid., led us to concentrate our efforts on these

31-03-1996; Teverga, Fresnedo, cerca de Paramo, 800 m,

characters. Peristomes of numerous Spanish U. crispa and

29TQH4077,

U. bruchii specimens were studied, especially those from

Lara, 23-07-1996. Lugo: Lugo, valle del Mino, 400 m,

the N.W. quadrant of the Iberian Peninsula, where both

29TPH1563, sobre Q. robur, Albertos, Garilleti, Lara &

mosses are frequent and commonly grow together. A total

Mazimpaka,

of 711 samples from 77 localities was studied. Basically,

Seceda, Bolsinos, cerca de la cascada, 700 m, 29TPH4519,

sobre Q. pyrenaica, Albertos,

28-10-1995;

Folgoso do

Garilleti &

Caurel,

Folgoso-

studies were carried out by light microscope in order to

sobre Q. pyrenaica, Albertos, Garilleti, Lara & Vergara,

find characters (preferably qualitative ones) that can be

06-01-1994;

used in routine identification work. In addition, SEM

29TPH3618, sobre Q. robur, Albertos, Garilleti, Lara &

Puebla

de

Brollon,

Covadelas,

700 m,

analyses of representative samples were made to support

Mazimpaka,

differences between the two taxa. Results were contrasted

Lara,

with those of Rosman-Hartog & Touw (1987) on Dutch

Fontela, 425 m, 20TPH6559, sobre Q. pyrenaica, Albertos,

and those of Smith & Proctor (1993) on British materials.

Garilleti, Lara & Mazimpaka, 02-01-1995; Pedrafita do

Cebreiro, Representative specimens studied

(When no indication is given, the materials are in the

authors' herbarium at Universidad Autonoma de Madrid).

27-10-1995;

02-01-1994;

hacia

Ibidem,

Navia

O

de

Albertos,

Suarna,

Portelo,

Garilleti

Munis,

&

Casa de

Valdepereas,

1200 m,

29TPH6432, sobre Q. pyrenaica, Garilleti, Lara & Mazim

paka, 06-12-1993. Ourense: Nogueira de Ramuin, Alber-

gueria-Parada, 630 m, 29TPG1193, sobre Q. pyrenaica, Garilleti, Lara & Mazimpaka, 13-05-1995; Parada de Sil, 480 m, 29TPG1992, sobre Q. pyrenaica, Garilleti, Lara &

Ulota bruchii

Mazimpaka,

13-06-1995;

Montederramo,

Sierra

de

S.

Mamede, Las Garbias (La Ferreria), 1200 m, 29TPG2575, SPAIN. Asturias: Degana, Cerredo, 950 m, 29TQH0258,

sobre Q. robur, Albertos & J.A. Lopez Rodriguez, 18-07-

sobre Q. pyrenaica, Albertos, Garilleti, Lara & Mazimpaka,

1997.

Pontevedra:

Forcarey,

Millerada,

800 m,

PERISTOMAL ORNAMENTATION IN ULOTA

Table 1.

275

Main peristomal differences between Ulota bruchii and U. crispa. Endostome Process

IPL ornamentation

Ulota bruchii

Linear, glaucous, opaque, delicate

Vertical or oblique lines with dispersed rough papillae

Ulota crispa

Triangular to subulate, hyaline,

Almost smooth or with low papillae; occasionally with

persistent

short lines

Exostome

Ulota bruchii

Configuration

OPL

PPL

Teeth tending to split and

Reticulations non-papillose

Papillose lines with papillae

irregularly reflexed

Cell areas convex

intercalated, sometimes longitudinally aligned

Ulota crispa

Teeth permanently fused in

Thick papillae and lines

Light striation and sparse papillae in

pairs and regularly recurved

Cell areas concave

the base, papillae in the upper two-thirds

29TNH5814,

sobre Q. pyrenaica, Albertos,

Garilleti &

robur,

Albertos

& J.A.

Lopez Rodriguez,

17-07-1997;

Lara, 21-07-1996; Fornelos de Monte, Moscoso, 350m,

Geres, a 3 km de Covide, 500 m, 29TNG62, sobre Olea,

29TNG4287, sobre Q. pyrenaica, Albertos, Garilleti &

Sim-Sim & Sergio, 28-10-1991 (LISU 161342); Serra do

Lara, 21-07-1996.

Geres, Ribeira da Lage, entrada para Leonte, 750 m, 29TNG72, en Acer, Sergio 5346 & R. Schumacker (LISU

PORTUGAL.

Minho:

Serra do

Gerez,

/.

Henriques,

154574).

junho 1885 (LISU 54110); Serra do Geres, Preguica, 200 m acima de Leonte, 850 m, 29TNG72, na base de Quercus, Sergio 2126, 30-08-1978 (LISU 154567).

Results and Discussion

Ulota crispa

Several peristomial characters afford an accurate discrimi nation of Ulota bruchii and U. crispa (Table 1). Firstly, the 450 m,

exostomes of the species differ in- the manner by which the

29TPH7562, sobre Q. pyrenaica, Albertos, Garilleti, Lara

SPAIN.

Asturias:

Ibias,

Santa

Comba,

teeth open for spore release: teeth of U. bruchii tend to

& Mazimpaka, 31-03-1996; Teverga, Fresnedo, cerca de

split into 16 processes (Rosman-Hartog & Touw, 1987,

Paramo, 800 m, 29TQH4077, sobre Q. pyrenaica, Alber

Figs 1 and 2; Smith & Proctor, 1993, Figs 1 and 5), reflex

tos,

do

irregularly when dry and the visible surface of the teeth

Caurel, Devesa da Rogueira, 1115 m, 29TPH5419, sobre

remains more or less concave. Teeth of U. crispa remain

Garilleti & Lara, 23-07-1996.

LUGO:

Folgoso

Q. robur, Albertos, Draper & Mazimpaka,

19-08-1998;

tightly fused in pairs (Rosman-Hartog, 1987, Figs 3 and

Puebla de Brollon, Covadelas, 700m, 29TPH3618, sobre

4), recurve regularly when dry and the visible surface of

Q. pyrenaica, Albertos, Garilleti, Lara & Mazimpaka, 27-

the teeth is plane.

10-1995.

Ourense:

29TNG7228,

Rodriguez,

sobre

Entrimo, Q.

17-07-1997;

robur,

Entrimo-Illa, Albertos

Blancos,

&

490 m,

J.A.

Pejeiros,

Lopez

800

m,

Other significant differences lie in the tooth ornamenta

tion. As quoted above, Rosman-Hartog & Touw (1987) pointed

out

differences in

the

ornamentation

of the

29TPG0248, sobre Q. pyrenaica, Garilleti, Lara & Mazim

exostomial PPL, but considered these characters difficult

paka,

to observe with the light microscope and therefore useless

11-03-1995;

Maceda,

A

Teixeira,

900 m,

29TPG2075, sobre Q. robur, Garilleti, Lara & Mazim

for the separation of U.

paka, 14-05-1995; Nogueira de Ramuin, Luintra, 630 m,

consistency

29TPG0496, sobre Q. robur, Garilleti, Lara & Mazim

substantiated by Smith & Proctor (1993), as well as by

paka, 13-05-1995; Chandreixa de Queixa, Queixa, 950 m,

the present study. Ornamentation of the exostomial PPL

of

this

bruchii and

differential

U.

crispa. The

ornamentation

was

29TPG2977, sobre Q. pyrenaica, Garilleti, Lara & Mazim

of U. bruchii is made of strong and papillose lines with

paka,

intercalated

14-05-1995.

Pontevedra:

Forcarey,

Millerada,

800 m, 29TNH5814, sobre Q. pyrenaica, Albertos, Garilleti & Lara, 21-07-1996.

papillae

that

frequently

appear

aligned.

Although these ornamentations seem to be irregularly

oriented, they commonly tend to be longitudinally linedup along the tooth (Fig. 3; Rosman-Hartog, 1987, Fig. 2;

PORTUGAL. Minho: Braga, Mata de Albergaria, Portela

Smith & Proctor, 1993, Figs 6 and 7). Under the light

do Homme, 770 m, 29TNG7228, sobre Q. robur, Albertos

microscope a pattern of fine lines, variously orientated,

& J.A. Lopez Rodriguez, 17-07-1997; Braga, campo do

and sparse papillae, is observed. In U. crispa the orna

Geres, hacia Albergaria, 740 m, 29TNG6724, sobre Q.

mentation is notably less marked: in the basal part of the

276

R. GARILLETI

Figures 3-8.

Comparison of the exostomes of U. bruchii and U. crispa. 3. SEM micrograph of PPL of U. bruchii, showing the marked

ornamentation of lines and papillae. 4. SEM micrograph of PPL of U. crispa, showing the light ornamentation consisting of lines and papillae in proximal cells, and only papillae in distal cells. 5. SEM view of OPL basal cells of U. bruchii; on the left side, a non-papillose reticulation giving a

convex profile to the persistent cell areas, can be observed. 6. Remains of OPL basal and middle cells of U. crispa; OPL has a concave profile and its ornamentation is dominated by thick papillae and lines; some lamellae can also be observed on the septae. 7. Light microscope view of the OPL in U. bruchii, showing the irregular ornamentation pattern, due to the prominent reticulation. 8. Light microscope view of the OPL in U.

crispa, showing its homogeneously papillose ornamentation.

tooth the ornamentation consists of a light longitudinal

(1993) found variations that are taxonomically signifi

striation with some sparse papillae; in the upper 2/3,

cant. In our opinion, the species show important differ

papillae

ences

are

predominant

(Fig.

4;

Rosman-Hartog

&

in

their

OPL

ornamentation

pattern.

When

Touw, 1987, Figs 3 and 4; Smith & Proctor, 1993, Figs 2

observed by SEM, cell areas of U. bruchii are convex,

and 3). Under the light microscope this ornamentation is

due to a high, non-papillose, reticulation (Fig 5; Smith &

hardly visible and the PPL appears smooth, or almost

Proctor, 1993, Fig. 8). Under the light microscope, the

so.

As for the external side of the exostome (OPL), neither Rosman-Hartog & Touw (1987) nor Smith & Proctor

ornamentation lines,

mainly

consists

of a very irregular pattern of

longitudinal

or

concentrically

orientated

(Fig. 7). In U. crispa, OPL cell areas are concave and

277

PERISTOMAL ORNAMENTATION IN ULOTA

Figures 9-12.

Comparison of the endostomes of Ulota bruchii and U. crispa. 9. General view of a process of U. bruchii. 10. General view of a

process of U. crispa. 11. Ornamentation of the internal side (IPL) of the proximal part of a U. bruchii process. 12. Ornamentation of the internal

side (IPL) of the proximal part of a U. crispa process.

the ornamentation is predominantly made of papillae,

is ornamented by fine but clear longitudinal or oblique

mixed with longitudinal lines, especially in the upper part

lines (Figs 11 and 13) which are always present in the

(Fig. 6; Smith & Proctor, 1993, Fig. 4); thus, under the

proximal part and often in the whole process; sparse

light microscope, the OPL appears homogeneously papil

thick

lose (Fig. 8).

predominant in the distal part. In

Although

these

exostomial

differences

represent

a

papillae

scope

endostome

predominantly

are

more

conclusive.

Like

the

also

observed,

being

sometimes

U. crispa, the IPL

appears smooth, or nearly so, under the light micro

useful tool for the discrimination of the two mosses, differences

are

and

has,

at of

most, small

a

very

papillae

light

ornamentation

(Figs

12

and

14;

exostome, the endostomes of the two mosses differ in

Rosman-Hartog

their

very short vermicular lines are intercalated, but these

configuration

and

ornamentation.

The

unique

problem of the use of endostomes is the fragility of

& Touw,

1987,

Fig.

4);

occasionally,

are never dominant.

processes, especially those of U. bruchii, which are occa sionally absent in poorly preserved specimens. As for the

endostome constitution, processes of U. bruchii are whit

Conclusion

ish and opaque, fragile, thin, linear and not wide at the

base (Fig. 9). Processes of U. crispa are hyaline, persistent

Peristomes of Ulota bruchii and U. crispa have a differ

and characteristically triangular (due to an enlarged base)

ential structure and ornamentation that affords an accu

or subulate (Fig. 10). In both taxa, processes are united

rate discrimination of the two mosses (Table 1). Among

by a thin connective membrane ornamented in a similar

the characters discussed, the ornamentation of the inter

way to the process base (Figs 9 and 10; Smith & Proctor,

nal side of the endostome (IPL) best discriminates the

1993, Figs 2 and 3).

taxa,

The character that best helps to discriminate the two taxa is the ornamentation of the endostome.

In both

since,

besides

its

ease

of use,

which

does

not

require long experience in the interpretation of peristome

structures,

we

have

not

found

intermediate

situations

mosses, the endostome external side (endostomial PPL)

that could lead to doubtful identifications. Comparison

is

of the two species on the basis of peristome morphology

smooth

(Figs

9

and

10)

and

only

(IPL) is differentially ornamented. The

the

inner

side

U. bruchii IPL

substantiates

the

specific

status

of

Ulota

bruchii,

as

278

R. GARILLETI £T,4L.

14

Figures 13-14.

Ornamentation of the endostomes of U. bruchii and U. crispa. 13. Light microscope view of a U. bruchii process, showing the

longitudinal striae. 14. Light microscope view of a U. crispa process, showing the smooth appearance of the IPL.

assessed by Rosman-Hartog & Touw (1987) and Smith & Proctor (1993).

References Albertos B, Lara F, Garilleti R, Mazimpaka V. 1999. Distribution and

abundance of corticolous species of the genus Ulota Mohr Musci,

Orthotrichaceae) in the NW Iberian Peninsula. Nova Hedwigia

Acknowledgements

70: 461^70. Rosman-Hartog N, Touw A. 1987. On the taxonomic status of Ulota

Financial

support

National

Institute

Ministry

was of

of Education

provided

Meteorology and

Culture,

by

the

and

the

grant no.

1111-CO2-01.

Spanish Spanish PB96-

bruchii Hornsch. ex Brid., U. crispa (Hedw.) Brid. and U. crispula Bruch ex Brid. Lindbergia 13: 159-164. Smith AJE, Hill MO. 1975. A taxonomic investigation of Ulota bruchii Hornsch. ex Brid., U. crispa (Hedw.) Brid. and U. crispula Bruch ex Brid. I. European material. Journal of Bryology 8: 423-433. Smith AJE, Proctor MCF. 1993. Further observations on the Ulota crispa complex. Journal of the Hattori Botanical Laboratory 74:

Taxonomic Additions and Changes: Nil.

171-182.

R. Garilleti, Departamento de Medio Ambiente, Facultad de Ciencias, Universidad Europea de Madrid, E-28670 Villaviciosa de Odon, Madrid, Spain. F. Lara, B. Albertos and V. Mazimpaka, Departamento de Biologia (Botanica), Facultad de Ciencias, Universidad Autonoma de Madrid, E-28049 Canto Blanco, Madrid, Espana.