Fig 1.
Geographic origin of the studied specimens.
(a) California and Nevada, (b) the Canary Islands, (c) Tenerife. Numbers indicate specimens included both in morphometric and phylogenetic analyses (see S1 and S2 Appendices). ** = original locality of O. shevockii, *** = original locality of O. kellmanii.
Fig 2.
Plant habit and dry capsule characteristics of specimens from the different geographic areas.
(a-d) Orthotrichum shevockii from Western North America; (e-g) samples from Tenerife; (h-i) O. kellmanii from California. (a, c, f and i) capsule detail; (b, d, e, g and h) habit; (e) two different habits from the same voucher. Scale bars: a, c, e and i = 0.5 mm, b, d, f, g and h = 1 mm. Vouchers: a-b, Shevock 13404 (CAS 958716, paratype); c, Shevock 21948 (CAS 1040048); d, Shevock 21802 (UC 1754431); f, Losada-Lima, León & Díaz s.n. (TFC-Bry 15904); e-g, Losada-Lima s.n. (TFC-Bry 17428); h, Shevock 32935 (MAUAM 5097); i, Shevock 32935 (NY 1140598).
Fig 3.
Leaf thickness variation and leaf cross-sections of specimens from the different geographic areas.
(a) Orthotrichum shevockii from western North America; (b) samples from Tenerife, (c) O. kellmanii from California. (a,b) from left to right: bistratose leaf (except base), leaf with a bistratose upper part and bistratose bands, leaf with dispersed bistratose bands in the upper part, leaf almost unistratose with bistratose patches around the apex. (c) top: bistratose leaf (except base), bottom: leaf with bistratose upper part and bistratose bands. Each leaf belongs to a separate individual. Cross-sections belong to a different leaf of the same individual. Arrowheads indicate bistratose strands or margins; in (c) they indicate the tristratose margins. Scale bars: leaves = 0.5 mm, cross sections = 100 μm. Vouchers: a, Shevock & Anderson 16754 (UC 1754230), Lara, et al. s.n. (MAUAM-Brio 3289), Shevock & York 13404 (CAS 958716, paratype of O. shevockii), Shevock 21802 (UC 1754431); b, J.M.B., J.G.M. & J.L.P s.n., (TFC-Bry 15957), Losada-Lima s.n. (TFCBry-17428), Losada-Lima, León & Díaz s.n. (TFC-Bry 15861), Losada-Lima, León & Díaz s.n. (TFC-Bry 15904); c, Shevock 32935 (NY 1140598).
Fig 4.
Capsule and peristome ornamentation of specimens from different geographic areas.
(a-d) Orthotrichum shevockii from western North America; (e-h) samples from Tenerife; (i-k) O. kellmanii from California. (a, e and, i) capsules with stomata mostly restricted to the neck; (b, f and j): exostome structure, showing the teeth lacunosity; (c, g and k) endostome internal layer (IPL) papillose ornamentation; (c and k) exostome internal layer (PPL), black arrows indicate striae at base; (d, h and l) endostome external layer (PPL) ornamentation; white arrows indicate lines or striae, sometimes forming plaques. Scale bars: a, e and i = 200 μm; b-c, f-g, j-l = 20 μm; d-h = 10 μm. Vouchers: a, Lara, et al. s.n. (MAUAM-Brio 3289); b, d, Shevock 13404 (CAS 958716, paratype), c, Shevock 21802 (UC 1754431); e, Losada-Lima s.n. (TFC-Bry 15567); f, Losada-Lima, León & Díaz s.n. (TFC-Bry 15904); g, Losada-Lima s.n. (TFC-Bry 17406); h, Losada-Lima, León & Díaz s.n. (TFC-Bry 15952); i-j, Shevock 32935 (MAUAM 5097); k-l, Shevock 32935 (NY 1140598).
Fig 5.
Principal component analysis (PCA) representing the first two components.
The percentage of variance explained by each component is given between brackets. Arrows represent the variables included in the analyses. cos2 represents the squared loadings for variables. ! = samples originally identified as Orthotrichum kellmanii.
Fig 6.
Beanplots of the quantitative variables for Orthotrichum shevockii.
Yellow = Tenerife (Canary Islands), blue = California (western North America, including O. kellmanii isotype materials). Individual observations are represented by small horizontal lines (in the case of multiple observations with the same values, the corresponding number of lines were merged), mean per group is shown by a bold long line and the mean for all data by a dotted line. Estimated density of the data distribution is displayed by the density shape in grey (for details see [48]). Stars indicate ANOVA significance values: * 0.05.
Table 1.
Quantitative characters evaluated for specimens of each geographic region, and results of quantitative morphometric analyses.
Fig 7.
Majority-rule consensus tree obtained in the Bayesian analysis.
Bayesian posterior probabilities (≥ 0.90) and maximum likelihood bootstrap values (≥ 70%) are shown above and below branches, respectively. Sequence labels of Orthotrichum shevockii are followed by identification number, geographical origin, and number identification between brackets as in Fig 1 and S1 and S2 Appendices. ** = paratype material of O. shevockii, *** = isotype material of O. kellmanii.
Table 2.
Characteristics of the four sequenced DNA regions and the resulting combined matrix used for phylogenetic analyses.
Fig 8.
Molecular dating and biogeographic analyses.
Maximum clade credibility tree from the relaxed molecular-clock analysis of the four loci in BEAST with an absolute nucleotide substitution rate (analysis I, mean = 4.453E-4, stdev = 1.773E-6subst./site/ma). Asterisks (*) at nodes refer to highly supported nodes (PP >0.95). Sequence labels are followed by identification number and geographical origin. In the case of Orthotrichum shevockii, sequence labels are also followed by an identification number between brackets as in Fig 1 and S2 Appendix (*** = isotype material of O. kellmanii). For the Orthotrichum group, letters in colored boxes in each node show the area or combination of areas with the highest probability of being ancestral, according to the reconstructions based on the DEC model implemented in BioGeoBEARS. Letters correspond to the following ancestral areas or combination of areas: W = western North America; E = eastern North America; N = Neotropics; M = Macaronesia; U = Europe; A = Asia. The complete probabilities of each biogeographical region are presented in S3 Fig.
Table 3.
Performance of competing models of ancestral-area estimation according to BioGeoBEARS.