Reproductive Success and Variation in Floral Traits in The

Biologia 64/2: 271—278, 2009 Section Botany DOI: 10.2478/s11756-009-0033-7

Reproductive success and variation in ﬂoral traits in the Iberian Peninsula endemic white campion Silene marizii (Caryophyllaceae)

Mónica García-Barriuso1,EvaM.Ávila1,M.AngelesSánchez-Anta1, Antonio L. Crespí2,SoniaBernardos1 &FranciscoAmich1

1Evolution, Taxonomy and Conservation Group (ECOMED), Department of Botany, University of Salamanca, E-37008 Salamanca, Spain; e-mail: [email protected] 2Herbarium/Botanic Garden, Environment and Life Technological Studies Center (CETAV), University of Trás-os-Montes eAltoDouro,P-5001-911 Vila Real, Portugal

Abstract: Silene marizii (Caryophyllaceae) is a schizoendemism of the west Iberian Peninsula. The correlation between the evolution of reproductive success (as measured in terms of fruit set and seed production) and five floral traits (peduncle length, calyx length, calyx width, petal limb length, and petal limb width) was investigated in five populations of S. marizii, taking into account both intra-populational and inter-populational variability. The populations studied represented the different habitats of S. marizii over its area of distribution. None of the five traits examined was significantly and positively correlated with the number of seeds produced by the flower. An analysis was also made of how floral morphology varies with the position of the flower in the inflorescence in the five populations. The populations from higher altitudes (Caramulhino, Puerto de Menga and Peña de la Cruz) had larger peduncles, calices and petal limbs than those living at lower altitudes (Sabugal and Mangualde) All five morphometric traits, plus the number of ovules per ovary, varied significantly between flower positions on the same plant and among populations. Key words: Silene marizii; Dioecius; floral morphology; ovule number; phenotypic variability; reproductive success; Por- tugal; Spain

Introduction patterns of variability found can be interpreted within the set of selective pressures that pollinators exert. Given the strong association between the evolution of One of the most common ways of measuring re- entomophilous plants and their pollinators, it is rea- productive success in angiosperms is fruit set (Zimmer- sonable to suppose that variation in floral morphology man & Aide 1989; Proctor & Harde 1994). Over the should be reflected by variation in individual repro- last few decades, different authors have followed vari- ductive success, which might lead to evolutionary di- ous approaches to study the variation in floral morphol- vergence and speciation. Variable morphological traits ogy and its effect on reproductive success (Schlichting that have no effect on reproductive success are un- 1986; Herrera 1990; 1993; Wolfe 1993; Johnson et al. likely to lead to evolutionary change (Herrera 1990). 1995; Diggle 1995; García-Cruz & Sosa 2007). In many plant species, the size and number of repro- In this work we investigated within-population ductive structures and the components of female re- variation in a number of floral characters of Silene ma- productive success show marked among-flower within- rizii Samp., an endemic of the western Iberian Penin- inflorescence variation (e.g. Ashman & Hitchens 2000). sula. We also assessed the variability of the charac- Floral variation may occur at several hierarchical levels ters among populations and among flowers at different (e.g. Williams & Conner 2001) including among flowers positions in the inflorescence. Studies of this type on within plants, among individuals that live in the same plants such as S. marizii (Guitián et al. 1997) are of site, or among plants in different populations. The rela- particular interest because they address the immediate tive contribution of individuals and populations to over- practical concerns of species conservation, and because all variability has evolutionary implications and can they may contribute to a better understanding of the give an insight on how inclined to local differentiation phenomenon of endemism (Kruckeberg & Rabinowitz is that particular plant species. 1985). The intraspecific variability of rare species (sensu Most of the studies that have evaluated reproduc- Rabinowitz 1981) has immediate evolutionary implica- tive success in angiosperms have included information tions (Primack 1980; Stebbins 1980). The study of flo- for only one or two species, in a reduced geographic ral characteristics of potential importance in the plant- area, and have only evaluated one o two floral traits pollinator relationship offers the advantage that the (García-Cruz & Sosa 2007). In the present study, five

c 2009 Institute of Botany, Slovak Academy of Sciences 272 M. García-Barriuso et al.

Fig. 1. Populations studied of Silene marizii in the Iberian Peninsula. morphological traits of this endemism of the western Silene marizii belongs to the section Elisanthe (Fenzl) Iberian Peninsula were studied in populations repre- Fenzl. It is a perennial herb, (15)20–60(70) cm high, densely senting its entire Iberian distribution. glandular and fetid, and has a pauciflorate dichasium. The The aims of this work, the first to be undertaken female flowers have a hardly noticeable carpophorus, much on the reproductive biology and ecology of this Iberian shorter than the capsule. Pollination is by insects, bee endemic member of the Caryophyllaceae, were: 1) to in- flies (Bombyliidae: Bombyliflorus fuliginosus), were cap- tured during the present fieldwork. Flowering starts in vestigate the variation of five floral morphological traits (April)-May and finishes at the beginning of July. Silene among flowers at different positions in the inflorescence, marizii, described by Sampaio (1909) from Mangualde and within populations, and among populations, and 2) to Serra do Caramulo (Portugal: Beira Alta Province), is en- determine whether these traits are related to reproduc- demic of the central western Spain and north-western Por- tive success, measured in terms of fruit set and seed tugal (Prentice 1977; Talavera 1990), where it occurs in a numbers. few populations. The species appears in the 2000 and 2007 issues of the Spanish Red List of Vascular Plants (Listas Ro- jas de la Flora Vascular Española) (VV.AA. 2000, Moreno Material and methods 2008) under the categories ‘Vulnerable’ (VU: B1 + 2b, D2) and “Critically Endangered” (CR: B2ab(ii,iii,iv,v)c(iv)) re- Study system and field sites spectively. Change of category is due to a continuing decline The nomenclature used and the boundaries of the species of area of occupancy, numbers of locations and mature in- recognised were those employed by Talavera (1990). The dividuals, and extreme fluctuations of number of mature syntaxonomic nomenclature followed was that suggested by Rivas-Martínez et al. (2001, 2002). The five study sites that individuals. were home to S. marizii belonged to the following phyto- Historical records of Silene marizii in the Iberian geographical units described by Rivas-Martínez (2005): Peninsula have been documented on the basis of a review Eurosiberian Region, Atlantic European Province, of the specialised scientific literature, and consulted docu- Galaico-Portugués sector (Montemouro-Caramulo District, mentation in several herbaria (BRESA, Technical Institute population 2 and 3). of Bragan¸ca, Portugal; COI, University of Coimbra, Portu- Mediterranean Region, Mediterranean West Iberian gal; HVR, University of Trás-os-Montes e Alto Douro, Vila Province, Estrellense Sector (Guardense District, popula- Real, Portugal; LISI, Instituto Superior de Agronomía, Lis- tion 1), Bejarano-Gredense Sector (Bejarano and Paramero- boa, Portugal; LISE, Esta¸cao Agronómica Nacional, Oeiras, Abulense Districts, populations 4 and 5, respectively). Portugal; LISU, Museu Nacional de História Natural; MA, Dioecy has been correlated with different ecological fac- Royal Botanic Garden of Madrid, Spain; MAF, Faculty of tors (Bawa 1980; Renner & Ricklefs 1995), suggesting that Pharmacy, University Complutense of Madrid; PO, Univer- these have favoured the evolution of dimorphism (Weller sity of Porto, Portugal; SALA, University of Salamanca, et al. 1995). However, in the genus Silene this seems un- Spain); abbreviations follow Holmgren et al. 1990 and Holm- likely since very similar ecological factors have been respon- gren & Holmgren 1993), where possible with direct exami- sible for the evolution of dioecy in all three sections of the nation. All sites with reports of S. marizii populations were genus (Desfeux et al. 1996). In any event, further studies visited to check for the presence of this species, as well a are needed to determine the influence of ecological factors number of other sites at which it might potentially occur. in the evolution of dioecy in Silene. When the species was detected, we recorded geographical lo- Reproduction and variation in floral traits in edemic Silene marizii 273

Table 1. List of populations and number of plants of Silene marizii used for morphometric analyses.

Taxa/ Localities UTM coordinates Altitude Temperature Precipitation N◦ individuals Date of N◦ population (m) ( ◦C) (mm) sampling

Silene marizii Population 1 PO: Beira Alta, Guarda, 29TPE5671 835 10.5 1195 22 25.5.2007 Sabugal Population 2 PO: Beira Alta, Mangualde 29TPE0696 605 No data No data 24 28.5.2006 Population 3 PO: Beira Alta, Caramulo 29TNE6788 1045 12.3 2166 33 1.6.2006 Population 4 SPA: Salamanca, Béjar 30TTK6372 1410 No data No data 35 3.6.2006 Population 5 SPA: Ávila, Sierra de la 30TUK3084 1475 9.6 1344 24 1.6.2007 Paramera, Puerto de Menga Total: 138

PO – Portugal; SPA – Spain.

Table 2. List of characters measured and scored for morphometric analyses of Silene marizii in Iberian Peninsula.

Morphological character Character states

1 Peduncle length (P) (mm) 2 Calyx length (CL) (mm) 3 Calyx width (CW) (mm) 4 Petal-limb length (PL) (mm) 5 Petal-limb width (PW) (mm) 6Numberofovules(NO) – Fig. 2. Dichasium of Silene marizii, showing the central (1) and lateral flowers (2 and 3). cation (a Garmin e-map Global Positioning System was used for geographically locating the taxa using 1 × 1kmUni- Peña de La Cruz, were marked; i.e., at least one plant out versal Transverse Mercator and geographical coordinates), of every three or four in each population was selected. The habitat and phenological data (i.e. number of reproductive following characteristics were measured in the field using an plants, number of vegetative plants, state of flowering, and electronic digital ruler (which allowed good precision): pe- state of fruiting). duncle length, calyx length, calyx width, petal limb width, Bioclimatic data (Temperature and Precipitation) have and petal limb length. These traits can potentially affect been obtained from Rivas-Martínez (2007) and Rivas- features such as the presentation of the flower to pollina- Martínez & Rivas y Sáenz (2007). tors, their potential to attract pollinators, and insect access Five populations of S. marizii were sampled for mor- to the nectar etc. The mature capsules (with seeds) of these phometric data. The study populations were situated in sev- plants were colleted immediately before dehiscence (always eral provinces of Portugal and Spain (Fig. 1, Table 1). Pop- within 4–5 weeks of marking). The number of seeds per cap- ulations of Mangualde and Puerto de Menga belong, respec- sule was later determined in the laboratory. At the same tively, to the classical sites of Melandrium viscosum (Mariz time, the length and width of the capsules were recorded. 1887) and M. glutinosum (Rouy 1894). Field sampling was The second data set was collected with the aim of in- performed between 15 May and 15 June 2006 and 2007. vestigating among-population and among-position variation Every attempt was made to coincide with the time of max- in floral morphology and their relationship with reproduc- imum flowering and fruiting for each population sampled. tive success in Silene marizii. In May 2006, 20 flowers at Table 1 show the differences in the flowering and fruiting inflorescence positions 1 and 2 (Fig. 2) were collected from times of the different populations. The sampling method a total of 10 plants belonging to each of the studied popu- used was designed to avoid the substantial differences in lations (Table 1) (i.e., 20 flowers per population and a total the number of individuals in each population having an ad- of 100 flowers. These numbers were deliberately low since S. verse influence on the results (see below). The states of five marizii is a catalogued, threatened species (VV.AA. 2000, macromorphological characters and one micromorphologi- Moreno 2008) and because some of the studied populations cal character were recorded and coded (Table 2). Vouchers were very small. The following characteristics were then de- for each population were prepared in the field and typically termined: peduncle length, calyx length, petal limb length, deposited at the Herbarium of the University of Salamanca, and the number of ovules per ovary. Spain (SALA). Analyses of morphological traits Data set design Morphological characters were scored from plants in natural The first data set was collected with the aim of investi- populations. The traits examined were selected according to gating the within-population variation in floral morphology those reported in previous studies (i.e. Guitián et al. 1997; and reproductive success in Silene marizii. In May of 2006 García-Cruz & Sosa 2007) and our initial field observations. and 2007, 22 randomly selected members of the Portuguese To evaluate correlation between fruit set and both in- population of S. marizii at Sabugal, and 24 and 35 mem- florescence and floral attributes, a least-square regression bers of the Spanish populations of Puerto de Menga and was carried out. To examine floral traits affecting fruit and 274 M. García-Barriuso et al.

Table 3. Mean ± standard deviation of the morphometric variables scored from the 81 ﬂowers (49 that set fruit and 32 that did not).

Localities Fruit/Not fruit Morphometric variables (see Tab. 2)

PCLCWPLPW 11.73 ± 5.27 13.14 ± 1.30 6.65 ± 0.67 6.70 ± 1.19 5.71 ± 0.88 Puerto de Menga Fruit (13) (7.43–21.24) (11.58–15.03) (5.8–7.26) (5.42–8.15) (4.24–6.8) 12.77 ± 4.75 14.21 ± 1.66 7.46 ± 1.06 8.20 ± 1.36 6.37 ± 1.10 Bejar, Pe˜na de la Cruz Fruit (23) (7.28–19.97) (11.63–15.8) (6.04–8.86) (6.43–9.93) (4.91–7.69) 11.19 ± 5.0 13.51 ± 0.98 6.93 ± 0.78 6.94 ± 0.70 5.34 ± 0.54 Sabugal Fruit (13) (4.96–18.17) (11.96–14.33) (6.09–8.17) (5.88–7.71) (4.61–6.07) PCLCWPLPW 14.28 ± 6.03 13.81 ± 0.94 7.41 ± 0.74 7.20 ± 0.88 5.72 ± 0.66 Puerto de Menga Not fruit (11) (7.61–21.26) (12.76–14.66) (6.5–8.04) (6.38–8.39) (5.34–6.08) 13.92 ± 4.45 14.64 ± 1.95 7.91 ± 0.77 8.68 ± 1.40 6.40 ± 0.94 Bejar, Pe˜na de la Cruz Not fruit (12) (9.84 ± 7.92) (12.6 ± 17.34) (7.07 ± 8.67) (7.65 ± 10.12) (5.39–7.48) 18.19 ± 6.41 14.07 ± 1.30 7.15 ± 0.87 8.08 ± 0.78 5.41 ± 0.97 Sabugal Not fruit (9) (10.31–32.74) (12.33–16.1) (6.21–9.11) (6.74–9.01) (4.02–6.44) PCLCWPLPW Fowers that 11.90 13.62 7.01 7.28 5.81 Total populations set fruit (49) (4.96–21.24) (11.58–15.8) (5.8–8.86) (5.42–9.93) (4.24–7.69) Flowers that 15.46 14.17 7.49 7.99 5.84 Total populations did not (32) (7.61–32.74) (12.33–17.34) (6.5–9.11) (6.38–10.12) (5.3–7.48)

seed production, a multiple regression analyses was used. 16 A forward elimination stepwise multiple regression was per- 14 formed with fruit set as the dependant variable, and ﬂo- 12 ral traits as independent variables. Analysis of variance de- 10 scribed the inﬂuence of the factors population and position 8

(in the inflorescence) on morphometric variables, and the 6 descriptive representation per class was performed by box- 4 plots. Relationships between variables were investigated by 2 Mean morphometric variables morphometric Mean calculation of Spearman‘s rank correlation coefficients, using 0 P Capsule the data from the second sample series. Relative variabili- CL CW Not capsule PL ties of the different morphometric traits were evaluated by Morphometric variables PW calculation of coefficients of variation, in order to displaying differences between populations analysed (Daniel 1999). Fig. 3. Variation (mean) of the morphometric variables (P: pe- Morphometric analyses were done by using the SPSS duncle length, CL: calyx length, CW: calyx width, PL: petal-limb length, and PW: Petal-limb width) from the flowers that set fruit version 11.5 (SPSS 2002) and STATISTICA version 7.0 and the flowers that did not. (StatSoft 2004).

Results nificant variations were also observed both within and among plants, but within-plants variation was greater Study group that among-plants variation. Silene marizii grows in low to middle elevations (600– Of the 81 flowers marked, 49 (60.5%) set fruit and 1500 m), in wide fissures of the large granitic “bolos” 32 (39.5%) did not (Table 3). Logistic regression showed common in the central western Iberian Peninsula. These that none of the five morphological variables examined communities belong to Rumici indurati-Dianthion lusi- had a significant effect on the probability of flowers pro- tani alliance (Bernardos et al. 2004). In the Table 8 ducing fruit. Neither did these traits have any effect on shows 3 relevés of these communities. the number of seeds per capsule (p > 0.01) (Fig. 3, Table 4). Floral traits and fruit set At the two flower positions all of the morphological No S. marizii hermaphrodite plants were found in the variables measured, and the number of ovules per ovary present study; in agreement, hermaphrodite plants of varied considerably among populations (Table 5). The S. dioica and S. latifolia are very rare (Desfeux et al. most variable characteristic was the size of the pedun- 1996). cle, while the least variable was the length of the calyx The results show significant variation in all plant (coefficients of variation 30.2% and 8.7% for position 1, traits within plants, among plants and among regions and 25.5% and 9.5% for position 2, respectively) (Fig. 4, (Tables 3, 5). All floral traits showed significant among- Table 5). At both flower positions the number of ovules region variation. The populations from higher altitudes per ovary was independent of the other variables anal- (Caramulhino, Puerto de Menga and Peña de la Cruz) ysed, as shown by the results of principal components had larger peduncles, calices and petal limbs than those analysis (Fig. 5). living at lower altitudes (Sabugal and Mangualde). Sig- Analysis of variance showed that the factor flower Reproduction and variation in floral traits in edemic Silene marizii 275

Table 4. Results of multiple regression to investigate the eﬀects of the three morphometric variables on number of seeds per ﬂower (n = 49).

Variable S.E. tp-value coeﬃcient

P −0.10285 0.299333 −0.34497 0.742476 CL 0.147783 0.293915 0.516778 0.63596 PL −0.15356 0.29536 −0.52649 0.5925

Table 5. Mean ± standard deviation of the variables (see Tab. 2) studied in the ﬁve populations of Silene marizii (position 1 and 2).

Population P1 P2 CL1 CL2 PL1 PL2 NO1 NO2

Mangualde 11.2 ± 3.3 6.7 ± 2 12.6 ± 1.4 12 ± 0.8 5.3 ± 0.5 4.8 ± 0.7 173 ± 26.1 178 ± 22.5 Puerto de Menga 17.5 ± 7.1 10.1 ± 3.7 13.3 ± 1.3 13 ± 25.7± 1.4 5.7 ± 0.7 132 ± 38.8 182 ± 36 Sabugal 151 ± 3.1 7.8 ± 0.8 11.6 ± 0.6 11.3 ± 0.8 5.1 ± 0.7 5 ± 0.5 206 ± 38.1 220 ± 30.2 Caramulinho 20.4 ± 5.7 10.1 ± 3.1 13.4 ± 1.5 12.7 ± 1.4 6.7 ± 1.8 5.6 ± 0.8 163 ± 31.9 180 ± 32 Béjar, Pena de la Cruz 18.6 ± 5.8 9.3 ± 1.5 15.5 ± 114± 17± 0.9 6.4 ± 1.1 169 ± 20 168 ± 27.3 All populations 16.5 ± 48.8± 2.22 13.3 ± 1.16 12.6 ± 1.2 5.9 ± 1.06 5.5 ± 0.76 168 ± 31 186 ± 1.6 Variation range 8.1–29.4 4.3–15.8 10–17.7 9.7–15.5 4.1–9.7 4.2–8.3 95–241 118–248 Varlation coeﬃcient 30.2 25.2 8.7 9.5 17.8 13.8 18.4 15.9

Fig. 4. Variation in three morphological traits (P: peduncle length, CL: calyx length, and PL: petal-limb length) of Silene marizii. Rectangles show 25th and 75th percentiles, circles indi- cate medians and whiskers 10th to 90th percentiles.

Fig. 5. Principal Components Analysis of eigth morphological variables of Silene marizii, based on 100 flowers of 50 individuals position had a significant effect on peduncle size, while of five populations. the factor population had no effect on any variable (Ta- ble 6). Each of the eight variables was significantly correlated with each of the other variables, as determined rare species (i.e. Rabinowitz 1981) such as S. ma- using a Spearman correlation matrix (p < 0.001) (Ta- rizii, a narrow endemic of the western Iberian Penin- ble 7). sula. However, the present results for this species suggest this hypothesis should be rejected; the in- Discussion dividuals and populations studied showed consider- able variation in terms of all the floral traits exam- In small populations that are adapted to a reduced ined. Both intra- and inter-populational components range of environmental conditions, the rapid fixa- thus make important contributions to overall variabil- tion of genes due to genetic drift has sometimes led ity. With respect to peduncle length and petal limb to genetic impoverishment (e.g. Babbel & Selander length, the variability recorded actually surpassed that 1974; Kruckeberg & Rabinowitz 1985). Reduced phe- shown by other members of the genus Silene from notypic variability might therefore be expected in the same territories and with wider distributions (i.e. 276 M. García-Barriuso et al.

Table 6. Results (F-value) of analysis of variance to investigate the eﬀects of the factor population and the factor position on the variables studied.

Factor Peduncle length Cáliz length Petal-limb length Number ovules/Ovary

Population 0.5 n.s.0.4n.s.0.1n.s.0.8n.s. Position 5*** 0.7 n.s.0.9n.s.1.4n.s. n.s.= not signiﬁcant; *** = p < 0.001

Table 7. Spearman’s correlations between all variables (position 1 and 2) studied (see Table 2). All correlations, positive or negative, are signiﬁcant (p < 0.001).

CL1 CL2 P1 P2 PL1 PL2 NO1 NO2

CL1–––––– – – CL20.90––––– – – P1 0.80 0.60 – – – – – – P2 0.50 0.60 0.70 – – – – – PL1 1.00 0.90 0.80 0.50 – – – – PL2 0.80 0.90 0.70 0.70 0.80 – – – NO1 −0.60 −0.70 −0.60 −0.90 −0.60 −0.60 – – NO2 −0.70 −0.60 −0.20 −0.20 −0.70 −0.30 −0.10 –

Table 8. Relevés of Rumici indurati-Dianthion lusitani al- rizii and its lack of special mechanisms for the dissem- liance (Phagnalo-Rumicetalia order, Phagnalo-Rumicetea in- ination of seeds, the genetic flow between the studied durati class). populations must be practically non-existent and the Numberofrelevés 123 colonisation of new areas very rare. Under such cir- Area (m2) 505060 cumstances the founder effect would be very important Coverage(%) 704030 ◦ in determining the characteristics of each population. Inclination ( ) – 10 60 Thus, under these conditions in which the founder ef- Altitude (m) 1045 605 1475 Exposure – NW N fect is strong and genetic flow between populations is reduced, the variation seen between the populations Characteristics of alliance, order and class might be expected. Silene marizii 322 Dianthus lusitanus 411 Umbilicus rupestris 211 Within-plant and population variation Digitalis thapsi .21 Numerous studies have suggested that variation in re- Sedum hirsutum 22. productive success is related to variation in floral char- Phagnalon saxatile 11. acters, and corolla size is an essential feature in the re- Rumex induratus .1. Anarrhinum duriminium .2. productive biology of plants (i.e. Herrera 1993, 2005). Polypodium cambricum 31. Typically, flower size is a continuously varying charac- Scrophularia herminii 1.. ter, and thus a reasonable candidate for analysis us- Silene acutifolia 1.. ing the methods of quantitative genetics. In the case of Sedum brevifolium 2.. Digitalis purpurea 1.. a dioecious species, such a Silene marizii,thereisan added dimension that there are two types of flowers, Accompanying species male and female, occurring on two types of plants. Asplenium billotii 112 All of the floral traits examined are potentially im- Ranunculus ollisiponensis 1.. Asplenium adiantum-nigrum .1. portant in the relationship of S. marizii with its pol- Parietaria lusitanica .1. linators since they govern flower presentation, the at- Corydalis claviculata 1.. traction of pollinators, and their access to nectar. Until Dryopteris oreades 1.. now, no data have been available on the identity of the Asplenium trichomanes 1.. pollinators of S. marizii; the present observations sug- Localition of relevés gest the main agents are bee flies (Bombyliidae: Bom- 1. Portugal, Beira Alta, Caramulo, Serra Caramulo, 29TNE6788, bylius fuliginosus). These insects, however, visit a wide 2.6.2007 range of flowers in the regions where the study popula- 2. Portugal, Beira Alta, Mangualde, Nuestra Senhora do Castelo, 29TPE0696, 2.6.2007 tions grow, and cannot be considered specific pollina- 3. Spain, Ávila, Mengamuñoz, Puerto de Menga, 30TUK3084, tors. We therefore consider that the selective pressures 1.6.2007 exerted by pollinators on the floral morphology of S. marizii, if they exist at all, are unlikely as significant as other factors that have much more important effects S. dioica and S. latifolia, Amich et al. unpublished on reproductive success. None of the five morphological data). variables studied appear to have any significant effect Given the use of non-specific pollinators by S. ma- on the probability that a flower will produce fruits, nor Reproduction and variation in floral traits in edemic Silene marizii 277 on the number of seeds that might be found in a cap- Bernardos S., Crespí A., Aguiar C., Fernández J. & Amich sule. Each floral feature of S. marizii examined varied F. 2004. The plant communities of the Rumici indurati- independently of all the others, suggesting an absence Dianthion lusitani alliance in the Lusitan Duriensean bio- geographical sector (NE Portugal and CW Spain). Acta Bot. of trends that might lead to the development of an inte- Gallica 151: 147–164. grated floral phenotype (Schlichting 1986). Reproduc- Daniel W.W. 1999. Biostatistics: a foundation for analysis in the tive success in this species appears not to be influenced health sciences. Wiley Series in Probability and Statistics: by the simultaneous effect of these floral traits. Applied Probability and Stattistics Section, 7th edition. John Wiley & Sons, Inc. New York. Delgado P., Pinero D., Chaos A., Perez-Nasser N. & Alvarez- Among-population variation Buylla E.R. 1999. High population differentiation and genetic The studied populations grow in relatively similar soils, variation in the endangered mexican pine Pinus rzedowskii 86: enjoyed similar conditions of exposure, and lived at sim- (Pinaceae). Am. J. Bot. 669–676. Desfeux C., Maurice S., Henry J.-P., Lejeune B. & Gouyon P.-H. ilar altitudes, etc. The distances between them (Fig. 1) 1996. 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Received November 20, 2007 Accepted June 16, 2008