How To Study The Use Of Moss In A Nativity Set

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1 Journal of Bryology (2006) 28: Mosses and other plants used in nativity sets: a sampling study in northern Spain F. LARA, E. SAN MIGUEL and V. MAZIMPAKA Universidad Autónoma de Madrid, Spain SUMMARY Bryophytes and vascular plants used in traditional home-made nativity sets were studied in an area of the Asturian Region, northern Spain. The results revealed a surprising plant diversity, with 66 bryophytes, three ferns and 37 flowering plants utilized. Most species, collected among more attractive mosses, were used only occasionally or accidentally, whereas only four large pleurocarpous mosses, Thuidium tamariscinum, Eurhynchium striatum, Hypnum cupressiforme and Pseudoscleropodium purum, were widely used, providing the moss base of all the sets. Additionally, eleven mosses and four native flowering plants were frequently selected. The diversity of the bryophytes used in nativity sets of different sizes is analysed, and the deliberate selection of moss species during the collecting is discussed. Finally, it is verified that the collection of certain showy mosses from forests and peat bogs could affect local populations of these mosses and entails the accidental removal of rare or endangered species. KEYWORDS: Nacimientos, crèches, bryophytes, ethnobotany, moss harvest impact, Asturias. INTRODUCTION The use of bryophytes for ornamental purposes is a widespread tradition among several cultures (Richardson, 1981; Glime & Saxena, 1991). One of the most representative examples of this use is the production of nativity sets, also known as nacimientos, crèches, presepi, etc. in different countries around the world. These scenes are among the most typical and outstanding ornaments in the Christmas celebration, consisting of a model representing the place of birth of Jesus. For this purpose, human and animal figures are placed in a setting built up with different natural and artificial materials around the stable of Bethlehem. The tradition with Christmas nativity scenes started in Europe (Díaz & Gómez, 1997). Their origin is attributed to St Francis of Assisi, at the beginning of the 13th century. Apparently, the Franciscan Order, based in southern France, was in charge of spreading this practice throughout the rest of Europe in the beginning of the following century. Nowadays this tradition is maintained to a greater or a lesser degree in various countries of western, central and southern Europe (e.g. France, Italy, Belgium, Switzerland, Austria, Germany and the Czech Republic). Regarding the introduction to Spain and subsequent dispersal to America, King Charles III is held responsible for spreading this tradition after his arrival from Naples, where it was a common practice. Even though in this first stage only noble and rich people used to make them (Díaz & Gómez, 1997), around the 18th century this practice became popular among the so-called lower classes (Aro et al., 1994). Currently, it is a widespread tradition in Spain and throughout Latin America. In Spain, as in many other countries, the use of moss in the preparation of nativity sets is generalized. They are only occasionally absent usually in the driest Mediterranean areas. Although in the last decades mosses have been frequently sold in local markets, mainly in the cities, they were traditionally collected from the natural or rural surroundings by the set creators themselves. Very little formal information on the species of bryophytes used for this purpose in different countries actually exists. Only a few data have been published referring to Central and North America. For Mexico, Rees (1976) mentions, among the mosses sold in Oxaca city, Campylopus sp., Dendropogonella rufescens (Schimp.) E.Britton, Dicranum sp., Hypnum sp. and Leptodontium sp.; Delgadillo & Cárdenas (1990) cite the use in that country of Hypnum, Thuidium, Leptodontium, Campylopus and Polytrichum to simulate grass in the nativity scenes. In # British Bryological Society 2006 Received 6 April Revision accepted 14 August 2006 DOI: / X152306

2 MOSSES IN NATIVITY SETS 375 Panama, Salazar Allen (2001) refers to the use of the mosses Thuidium delicatulum (Hedw.) Schimp., Hypnum sp., Leptodontium sp., Breutelia tomentosa (Sw. ex Brid.) A.Jaeger, Rhacocarpus purpurascens (Brid.) Paris, Sematophyllum cuspidiferum Mitt., and of some species of liverworts belonging to the genera Frullania and Lepidozia. Moss harvesting for commercial purposes at Christmas may entail risks for the conservation of the forests where they are collected, and has been denounced by several authors: Gómez Peralta & Wolf (2001) estimated that, each season, a single family could pick up from a natural reserve in Mexico nearly 50 tons of terrestrial moss to sell in Christmas markets. Delgadillo (2004) points out the frequent use in that same country of carpets of Thuidium delicatulum and Hypnum amabile (Mitt.) Hampe, and how, nowadays, species of Campylopus and Leptodontium are also used because of the gradual scarcity of the former. Arrocha (1996) and Salazar Allen (2001) explain how in Panama the mosses sold in markets come mainly from tropical mountain cloud forests around the Barú volcano, protected as a National Park. Each harvester collects up to 20 sacks of moss every year, each one containing 50 packets (30630 cm) filled with epiphytic bryophytes. So far, no study has been made either on the mosses used in traditional home-made nativity sets, or on the environmental effects potentially caused by their harvesting. Yet, thousands of families still use mosses to build nativity scenes every year in many countries. The present study tries to offer a first perspective on the use of bryophytes and other plants in traditional nativity scenes. The basic objectives of this analysis are to assess which species are preferred, and if their use causes any environmental damage. For this purpose, a rural area in the Atlantic area of northern Spain was chosen, since many traditions are still alive there (San Miguel, 2004) and bryophytes are very abundant. METHODS Bryophytes and vascular plants used in the building and decoration of home-made nativity sets were studied in different populations of Piloña township, Asturias Region (Fig. 1). This mountainous rural area is characterized by its Atlantic climate. The landscape is dominated by a mosaic of meadows and patches of oak or mixed deciduous forests, together with Alnus glutinosa and willows along the streams, and some Fagus sylvatica forests in the northern humid slopes, and is representative of northern Spain. The study took place in the Christmas period between the end of year 2001 and the beginning of The nativity scenes sampled were all those found in churches, private business and private residences in the villages and farms surrounding the town of Infiesto. A total of 26 scenes of various sizes, locations and levels of complexity (Table 1), were studied. Whenever possible, the creators of the scenes were interviewed about the plant elements found in the nativity sets (namely, the collecting site and the reasons for Figure 1. Location of Piloña township. the moss choice). In all cases, the total surface of the display was estimated, and the species and uses of vascular plants found inside were noted. As for bryophytes, with the owner s approval, samples were taken of all the species distinguished after a careful analysis of the display. In order to analyse the possible differences depending on the dimensions of the scenes, three size categories were established: the displays measuring 1 m 2 or less were Table 1. sizes List of the studied nativity sets, grouped according to their Set Locality Situation Size (m 2 ) S-1 Beloncio Commercial establishment 0,4 (bar) S-2 Espinaredo Commercial establishment 0,2 (bar) S-3 La Piñera Private home 0,3 S-4 Sevares Private home 0,3 S-5 Sevares Private home 0,1 S-6 Sevares Commercial establishment 0,2 (shop) S-7 Antrialgo Private home 0,6 S-8 Villamayor Private home 0,4 S-9 Villamayor Private home 0,8 S-10 Melarde Private home 0,4 M-1 Areñes de Beloncio Private home 3,0 M-2 Infiesto Commercial establishment 1,4 (bank) M-3 La Piñera Private home 1,5 M-4 Valles de San Román Private home 3,8 M-5 Villamayor Private home 1,5 M-6 Villamayor Private home 1,1 M-7 Villamayor Private home 1,5 M-8 Villamayor Private home 1,1 M-9 Villamayor Private home 2,2 L-1 Beloncio Church 10,0 L-2 Villamayor Neighbourhood association 39,0 L-3 Villamayor Church 6,0 L-4 Espinaredo Church 28,0 L-5 San Román Church 8,0 L-6 La Piñera Private home 5,3 L-7 Miyares Church 10,0

3 376 F. LARA ET AL. Figure 2. A nativity set (L4) in which mosses cover a large area of the display. considered small (S1 S10); those whose size ranged between 1 and 5 m 2 were considered medium (M1 M9), and those larger than 5 m 2 were considered large displays (L1 L7). The identification of the bryophytes was carried out in the Bryology Laboratory at Universidad Autónoma de Madrid, where the sample vouchers are kept. Hill et al. (2006) was followed for moss nomenclature and systematics, and Grolle & Long (2000) for liverworts. The nomenclature of vascular plants follows the criteria of Flora Iberica (Castroviejo, ) and of Aizpuru et al. (1999) for the groups still unpublished in the former. Bryophytes RESULTS In all the nativity sets studied, mosses were used to carpet a more or less extensive area of the scene (Fig. 2). They were particularly useful to cover the base and the elements that represented the mountains in order to simulate fields, scrubland or forests. In the most accurate representations where the arid scenery dominated, mosses were set along the rivers, shaping a lush riverside vegetation (Fig. 3). Mosses were also used secondarily to cover seams and ornate the roofs or other architectural elements. The section of the display covered with moss varied between 10 and 80% of the total surface and, in general, it was more important in the smaller sets. As a whole, the moss carpet covering the 26 sets studied added to a surface of about 30 m 2. As in most of the northern fringe of the Iberian Peninsula, obtaining moss is a very easy task in the studied area, a fact that has been confirmed by the majority of the nativity-set creators interviewed. Most of them (67%) affirmed that the mosses had been collected from the carpets covering artificial walls or along the paths surrounding their homes or villages. In other cases (22%) they reported to have walked a little further, looking for humid areas, but still not into the forests. Only a small percentage (11%) confessed to have obtained the bulk of the moss directly from the surrounding forests. Moss is harvested every year in almost all cases, and only two people stated that they had kept dry mosses from one year to the next. A total of 66 species of bryophytes were recorded (Table 2). The liverworts were represented by 12 species, all of them foliose, belonging to 10 genera and 8 families. Mosses were much more abundant, up to 53 species and one variety, belonging to 42 genera and 20 families. The acrocarpous mosses include 37% of the species whereas 63% are pleurocarpous. The best represented families are the Brachytheciaceae (13 species, 10 genera), the Hylocomiaceae (6, 4), the Pottiaceae (5, 4) and the Hypnaceae (4 species and 1 variety, 3 genera). Four species were the most frequent mosses in the sets: Thuidium tamariscinum (found in 77% of the nativity sets), Eurhynchium striatum (73%), Hypnum cupressiforme (69%) and Pseudoscleropodium purum (65%). These were followed by Polytrichastrum formosum (42%), Kindbergia praelonga, Homalothecium sericeum, Leucobryum juniperoideum and Rhytidiadelphus triquetrus (38%), Neckera complanata (35%) and Rhytidiadelphus loreus (31%). Other frequently used mosses were Loeskeobryum brevirostre (27%), Anomodon viticulosus, Ctenidium molluscum, Hylocomium

4 MOSSES IN NATIVITY SETS 377 Figure 3. A nativity set (L2) in which mosses are preferentially set along the simulated riverside. splendens (23%), Brachythecium rutabulum and Mnium hornum (19%). Considering the sizes of the scenes, the seven large sets (L1 L7) comprised 45 bryophytes in total, ranging from 10 to 19 species in each set, with an average of 14.4 species. In all of them the mosses Eurhynchium striatum and Thuidium tamariscinum were present, while Pseudoscleropodium purum was absent in only one of them. Other species recorded in more than half of the scenes were Brachythecium rutabulum, Ctenidium molluscum, Hypnum cupressiforme, Neckera complanata, Rhytidiadelphus loreus and Rhytidiadelphus triquetrus. The nine medium-sized sets (M1 M9) also comprised 45 species, although the number of species in each set varied from 7 to 15, and the average was only 10.4 species. Only five mosses were found in more than half of them, namely (in order of decreasing frequency): Thuidium tamariscinum, Hypnum cupressiforme, Leucobryum juniperoideum, Eurhynchium striatum and Polytrichastrum formosum. Finally, the 10 small nativity sets studied (P1 P10) only contained 29 species, ranging from 2 to 10 in each set with an average of 6.5. The only species used in at least half the cases were Eurhynchium striatum, Hypnum cupressiforme, Pseudoscleropodium purum and Thuidium tamariscinum. Other plants In most of the nativity sets, fragments of other plants were used for ornamental purposes (Table 3). In general, small twigs were used to resemble trees in the scenery; while sometimes bark was preferred to build up the stable and to simulate mountains. Only occasionally leaves or fruits were used as a decoration. Together with the mosses, many of these elements are collected every year from the surroundings of the houses, although the non-decaying bark is frequently kept for several years. Some species, such as Quercus suber and Limonium sinuatum are invariably bought, since they do not grow in the area. In other cases, such as some ferns and small flowering plants, the whole plant is collected and included in the carpet of mosses. On the whole, 40 species of vascular plants were identified (Table 3), including 3 ferns, 5 conifers and 32 flowering plants. Only a few of them reappeared with some constancy in the sets studied: oak trees (Quercus robur and Q. petraea) were the most used (35 % of the sets), followed by ivy (Hedera helix, 31%), Butcher s broom (Ruscus aculeatus, 27%), statice (Limonium sinuatum, 23%), and Quercus suber and Polypodium sp. (19%). The remaining species were recorded in fewer than five sets. Regarding lichens, small colonies of Cladonia were found in three of the sets, in some cases picked up among the moss carpets, and occasionally selected for their attractive appearance. DISCUSSION In Spain, apart from local traditions like that of moss men in Béjar (Martínez Abaigar & Núñez Oliveira, 2001), the use of bryophytes for ornamental purposes is centred on the display of nativity sets, which is a very popular practice throughout the whole country. In Piloña, where the present study took place, the tradition of setting up a nativity scene is fully alive

5 378 F. LARA ET AL. Table 2. Distribution of the bryophyte species among the nativity sets Taxa/set L1 L2 L3 L4 L5 L6 L7 M1 M2 M3 M4 M5 M6 M7 M8 M9 S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 n Calypogeia fissa x 1 Diplophyllum albicans x 1 Frullania tamarisci x x 2 Lejeunea cavifolia x x x 3 Lophocolea bidentata x x x 3 Plagiochila porelloides x 1 Porella arboris-vitae x 1 Porella obtusata x 1 Porella platyphylla x x x x 4 Radula complanata x x 2 Saccogyna viticulosa x x 2 Scapania nemorea x 1 Anomodon viticulosus x x x x x x 6 Atrichum undulatum x 1 Barbula convoluta x 1 Brachythecium albicans x 1 Brachythecium rutabulum x x x x x 5 Brachythecium salebrosum x x 2 Brachytheciastrum velutinum x 1 Bryum capillare x x 2 Calliergonella cuspidata x x x x 4 Cirriphyllum piliferum x x 2 Ctenidium molluscum x x x x x x 6 Dicranodontium denudatum x 1 Dicranum scoparium x x 2 Kindbergia praelonga x x x x x x x x x x 10 Eurhynchiastrum pulchellum x x x 3 Eurhynchium striatum x x x x x x x x x x x x x x x x x x x 19 Funaria hygrometrica x 1 Grimmia trichophylla x 1 Homalothecium sericeum x x x x x x x x x x 10 Hylocomium splendens x x x x x x 6 Hypnum andoi x 1 Hypnum cupressiforme x x x x x x x x x x x x x x x x x x 18 Hypnum cupressiforme var. lacunosum x 1 Isothecium myosuroides x x x x 4 Leucobryum juniperoideum x x x x x x x x x x 10 Leucodon sciuroides x 1 Loeskeobryum brevirostre x x x x x x x 7 Mnium hornum x x x x x 5 Neckera complanata x x x x x x x x x 9 Neckera crispa x x x x 4 Orthotrichum anomalum x 1 Oxyrrhynchium hians x 1 Oxyrrhynchium pumilum x 1 Plagiomnium rostratum x x 2 Plagiomnium undulatum x x 2 Plagiothecium curvifolium x 1 Plagiothecium undulatum x x 2 Pleurozium schreberi x 1 Polytrichastrum formosum x x x x x x x x x x x 11 Pseudoscleropodium purum x x x x x x x x x x x x x x x x x 17 Pseudotaxiphyllum elegans x 1 Rhynchostegium confertum x 1 Rhytidiadelphus loreus x x x x x x x x 8 Rhytidiadelphus squarrosus x x x x 4 Rhytidiadelphus triquetrus x x x x x x x x x x 10 Schistidium crassipilum x 1 Sphagnum quinquefarium x 1 Sphagnum subnitens x x 2 Thamnobryum alopecurum x x x 3 Thuidium tamariscinum x x x x x x x x x x x x x x x x x x x x 20 Tortella tortuosa x x 2 Trichostomum brachydontium x 1 Trichostomum crispulum x 1 Weissia controversa x 1 Total

6 MOSSES IN NATIVITY SETS 379 nowadays, and is practised in different public buildings and private homes (Table 1): (1) they are present in all churches, where their size is generally quite large; (2) sometimes they are also built in the rooms of certain neighbourhood associations, where they can achieve amazing complexity and extension; (3) in some commercial establishments (banks, bars, shops), generally of medium or small size; and (4) in private homes, by far the commonest situation, where the sets are small or medium sized and only occasionally large. However, the local elders recall how 50 years ago nativity sets were only made in churches (San Miguel, 2004), and this was substantiated for the neighbouring region of Cantabria (Pardo de Santayana, 2003). In general, local nativity scenes are quite lax and imaginative recreations, where mosses are used extensively and other vegetal elements appear more or less abundantly. They make up a scene that resembles more the characteristic green landscape of the Atlantic region than that of the arid Palestine where the emulated events really happened. Species diversity and selection The results of this study reveal the use of a surprisingly high number of local bryophytes, although not all of them are used in the same way or with similar frequencies. During the interviews conducted, most of the set owners affirmed not to distinguish between moss species, with statements like moss is all the same thing. However, some of them did select certain moss forms because of their special characteristics. Such is the case with Leucobryum juniperoideum, attractive for the shape, size and colour of its large cushions, to the point that some of the informants were able to describe the habitat and substrate where they grow: dead chestnut tree logs in forested areas. In a similar Table 3. List of the vascular plants encountered, the parts of the plant used and the number of nativity sets where they were displayed Taxa Part used No. of sets Acacia dealbata Twigs 1 Aloysia citrodora Twigs 1 Asplenium trichomanes subsp. quadrivalens Whole plant 3 Buxus sempervirens Twigs 1 Castanea sativa Bark 3 Chamaecyparis lawsoniana Twigs 1 Corylus avellana Twigs 3 Crataegus monogyna Twigs 1 Cupressus sempervirens Twigs 2 Daboecia cantabrica Twigs with leaves 2 Erica spp. Twigs with leaves 4 Eucalyptus globulus Bark 1 Fagus sylvatica Dried leaves 3 Fragaria vesca Whole plant 1 Fraxinus excelsior Twigs 1 Gallium aparine Stems 2 Hedera helix Twigs 8 Ilex aquifolium Twigs 2 Laurus nobilis Twigs 1 Limonium sinuatum Dried inflorescence 6 Malus domestica Fruits 1 Oxalis acetosella Whole plant 1 Pinus radiata Bark 1 Twigs 1 Polypodium spp. Whole plant 5 Polystichum setiferum Fronds 1 Prunus avium Twigs 1 Prunus persica Twigs 1 Pseudotsuga menziesii Twigs 1 Pyracantha crenulata Fruits 1 Quercus petraea, Q. robur Bark 3 Twigs 4 Dried leaves 2 Quercus suber Bark 5 Rosmarinus officinalis Flowering twigs 3 Ruscus aculeatus Twigs 7 Thuja plicata Twigs 1 Thymus praecox Twigs 1 Trachycarpus fortunei Leaf portions, fibres 1 Ulex europaeus Twigs 1 Umbilicus rupestris Whole plant 3 Viola alba Whole plant 3 Viscum album Twigs 2

7 380 F. LARA ET AL. way, the frequently used acrocarpous moss Polytrichastrum formosum was selected for its size and resemblance to small trees. Finally, species of the genus Sphagnum, called white moss or beautiful moss by some owners, were used exceptionally, and were especially appreciated in the composition of the scene. Thus, some moss species are consciously preferred, distinguished and selected, but still many more are selected in a more instinctive way. This is most probably the case for the four most frequent species (.65%), which have their large size and attractiveness in common: Thuidium tamariscinum, Pseudoscleropodium purum, Hypnum cupressiforme and Eurhynchium striatum. These species are used in large quantities and they make up the bulk of the moss in all the compositions. At least one of them, and often more, appears in every set studied. They are very frequent in the area, and they are selected during harvest because of their size, showiness and the extent of their carpets. Significantly, in Mexico and Panama the genera Thuidium and Hypnum were also especially chosen for these same purposes (Salazar Allen, 2001; Delgadillo 2004). Nelson & Carpenter (1965) pointed out that in USA mosses of these genera are the most frequently used for decoration. According to Arrocha (1996) moss collectors for Christmas markets in Panama also select them for their colour and shape, and consistently use species from only eight genera. Among the generally selected species, together with Leucobryum, Polytrichastrum and the four most common pleurocarpous mosses, the rest of the large, showy, pleurocarpous species commonly used are Kindbergia praelonga, Homalothecium sericeum, Rhytidiadelphus triquetrus, Neckera complanata, Rhytidiadelphus loreus, Loeskeobryum brevirostre, Anomodon viticulosus, Ctenidium molluscum and Hylocomium splendens. The fact that some of these were individually selected for some special place in the composition (edges, rivers, gardens, etc.) confirms this preference. All of these bryophytes are distinguished and selected by a good number of collectors. Only a few vascular plants can be considered to be generally selected: the species of Quercus and Ruscus aculeatus are the only indigenous examples, and Limonium sinuatum is frequently bought. Hedera helix is sometimes chosen, but the high frequency of appearance in the nativity sets is mostly due to the presence of fragments of the plant embodied in the moss carpets. Some other species were collected only occasionally, but they seem to have been actively chosen because they dominate the harvested fragments. These are less common or less attractive mosses, and were selected only by a limited number of nativity set designers. For example, the liverworts of genus Porella, the acrocarpous mosses Dicranum scoparium, Mnium hornum and Plagiomnium spp., as well as Sphagnum spp. and many pleurocarpous species (Brachythecium rutabulum, Isothecium myosuroides, Neckera crispa, Plagiothecium spp., Rhytidiadelphus squarrosus, Thamnobryum alopecurum, etc.). In total, this category of occasionally selected plants can sum up to 30% of the recorded mosses. This is also the case for most of the vascular plants and the lichens of genus Cladonia. The remaining plants found in the displays can be considered as accidental, since they were collected randomly, mixed in between the carpets of the selected bryophytes. They represent nearly 44% of the bryophyte catalogue, and among them are almost all the liverworts, most acrocarpous mosses and some pleurocarpous ones, such as the smaller members of Brachytheciaceae, and Calliergonella cuspidata or Pseudotaxiphyllum elegans. Some vascular plants belong to this category as well: the ferns Polypodium spp., and Asplenium trichomanes subsp. quadrivalens, and the flowering plants Fragaria vesca, Oxalis acetosella, Umbilicus rupestris, and Viola alba. Possible impacts of moss harvesting The set up of nativity scenes is a traditional activity, that is repeated every year for Christmas, and a more or less important mass of bryophytes is collected for this purpose. Up to date, it has not been possible to assess the moss volume extracted annually because of the lack of studies on the number of families that use them, or on the quantity of moss harvested. In addition, it has been found that a small proportion of the families keep some or all the mosses from one year to the next one, while in other cases a higher quantity of moss than needed is collected and afterwards thrown away. This is particularly the case of the largest and most elaborate scenes. As a rough estimate, the individual harvesting of moss by numerous families from each village could add up to a substantial quantity of bryophyte cover being removed: at least several tens of square metres, according to the data obtained in this study. The impact of such a collection could be more or less severe depending on the area of harvest, whether it is a previously altered environment or a natural, sensitive habitat. Most of the nativity-set makers claim to have picked up the moss only from the carpets covering walls and paths near their homes. However, in many of the sets species characteristic of forested areas (i.e. Leucobryum juniperoideum, Plagiomnium spp., Plagiothecium undulatum) or peat bogs (i.e. Sphagnum spp.) were present. In fact, the results from the analysis of the bryophyte composition of each set point out that in the smaller displays (S) the mosses come almost exclusively from anthropogenic habitats; on the contrary, in the larger scenes (M and L) it seems common that at least some of the mosses come from less disturbed habitats or, occasionally, exclusively from forests or especially damp soils. As mentioned above, the generally preferred mosses belong to abundant species in the area, most of them from ruderal environments. The only exception to this pattern is Leucobryum juniperoideum, sought in forested areas because of its very attractive appearance. In spite of this, this species is still common in the forests of Piloña, and although its harvest could potentially threaten its local populations, no studies have been carried out to provide evidence on this matter. In general, the harvest of occasionally selected species does not seem to cause a heavy environmental hazard. Such

8 MOSSES IN NATIVITY SETS 381 species are collected less frequently and in smaller quantities. Nevertheless, a number of them are picked up from especially sensitive environments and exceptionally, in the case of Sphagnum, they can be collected in great quantities. The major risk of their harvesting is the accidental collection of rare or endangered companion species. In the present study, two rare, accidentally harvested mosses were found; both of them were unknown from the Asturian region before this study. The first one, Plagiothecium curvifolium, is rare in the Iberian Peninsula (Sergio et al., 1994), and is only known from a small number of localities in the provinces of Burgos, Santander, León and Gerona. It was found in a small home-made nativity set (S9, one of the most diverse small sets), but the creator of the scene could not give details on the moss collecting site. The second one is Dicranodontium denudatum, a more widespread species in the north of the country (La Coruña, Lugo, Guipuzcoa, Navarra, Lérida and Gerona) but equally rare on the Iberian scale. According to the owners of the nativity set where it was spotted (L4, one of the largest and most complex in the study) it was collected from Espinaredo Valley, a specially damp area in the township, where some peat bog areas are conserved. CONCLUSIONS The diversity of plants used in Asturian nativity sets is high. More than half of the bryophytes and most of the vascular plants are selectively harvested, although only 15 species of mosses and 3 of flowering plants are preferred by.20% of the creators of the sets. Only the pleurocarpous mosses Thuidium tamariscinum, Eurhynchium striatum, Hypnum cupressiforme and Pseudoscleropodium purum are used widely, representing the basic plant ornamentation of all the displays. The complexity and plant composition of the different types of nativity sets is very variable. The smaller ones incorporate few species and scarce moss biomass. They are generally composed of plants from walls and pathways, so they rarely contain ecologically demanding mosses. For the larger displays, large quantities of moss are used, frequently harvested from forests and peat bogs: the proportion of species from sensitive habitats can reach considerable importance. Although the harvesting is basically carried out in anthropogenic environments, and the impact generated by this activity could be relatively low, the search for selected material by some of the collectors could threaten the populations of some species, particularly some rare bryophytes that are accidentally extracted. As for some flowering plants in Spain (i.e. Holly, Ilex aquifolium), the harvest of mosses for ornamental purposes should be regulated, including legislation against collecting from forests and damp soil. ACKNOWLEDGEMENTS Clotilde Arocha, Elena Aguirre, Claudio Delgadillo and Janice Glime are gratefully acknowledged for helping with literature. We are also very grateful to Lars Hedenäs and two anonymous referees for their suggestions on a previous draft. This work was partly funded by the Spanish Ministry of Education and Science, grants CGL and AP TAXONOMIC ADDITIONS AND CHANGES: Nil. REFERENCES Aizpuru I, Aseginolaza C, Uribe-Echevarría PM, Urrutia P, Zorrakin I Claves ilustradas de la Flora del País Vasco y territorios limítrofes. Vitoria-Gasteiz: Servicio Central de Publicaciones del Gobierno Vasco. Aro E del, González C, Padilla C, Timón MP España: fiesta y rito. Fiestas de invierno. Madrid: Ediciones Merino. Arrocha C Impacto ambiental de la tradición de usar briofitos en los nacimientos de la Navidad. Briolatina 38: 4. Castroviejo S, ed Flora Iberica. Madrid: Real Jardín Botánico de Madrid, CSIC. Delgadillo MC Editorial. Briolatina 51: 1. 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MAZIMPAKA, Departamento de Biología (Botánica), Facultad de Ciencias, Universidad Autónoma de Madrid, c/darwin 2, E Madrid, Spain. francisco.lara@uam.es