Seed-Coat Microsculpturing and Its Systematic Application in Isatis (Brassicaceae) and Allied Genera in Iran Hamid Moazzenia, Shahin Zarrea,Ã, Ihsan A

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Seed-coat microsculpturing and its systematic application in Isatis (Brassicaceae) and allied genera in Iran Hamid Moazzenia, Shahin Zarrea,Ã, Ihsan A. Al-Shehbazb, Klaus Mummenhoffc aDepartment of Botany, School of Biology, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran bMissouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166-0299, USA cUniversita¨t Osnabru¨ck, Spezielle Botanik, Barbarastrasse 11, 49076 Osnabru¨ck, Germany

Received 2 June 2006; accepted 19 October 2006

Abstract

In order to examine the systematic application of seed-coat microsculpturing in Isatis, seed surfaces of 23 species (41 populations) in four genera of tribe Isatideae were examined using scanning electron microscopy (SEM). Eight types of basic ornamentation patterns were recognized among the studied specimens. Of these, the reticulate–areolate type was the most common and was found in the genera Isatis, Pachypterygium, Samerari and Tauscheria and 15 species (e.g., I. cappodocica, I. kotschyana and I. tinctoria). The reticulate type, the second most frequent, occurred in 7 species while other types each were represented by only one or 2 species. Although different populations of a given species show similar seed-surface sculpturing in most cases, in some polymorphic species like I. cappadocica and I. kotschyana these patterns were variable among populations. To some extent the variation corresponds to infraspeciﬁc taxa for some species, but the differences are not signiﬁcant enough to be useful in the delimitation of the subspecies recognized by previous workers. Moreover, seed-coat characters do not support the separation of genera Isatis, Pachypterygium, Sameraria and Tauscheria. r 2007 Published by Elsevier GmbH.

Keywords: Brassicaceae; Isatis; Sameraria; Intraspeciﬁc classiﬁcation; Seed-coat microsculpturing; Iran

Introduction even in fruits, which provide the most valuable diagnostic characters (Davis, 1965; Hedge, 1968; Jafri, Isatis L. comprises approximately 79 species (Al- 1973). This pattern of variation might suggest that Shehbaz et al., 2006) and the genus is distributed hybridization may have played a role in the evolution of primarily in the northern hemisphere, especially in the the genus. Notes on intermediate morphological char- Irano-Turanian region where nearly 90% of its species acters of Isatis specimens have been frequently made, grow (Appel and Al-Shehbaz, 2003; Davis, 1965). Isatis even among some taxa that are morphologically distinct species are sometimes highly polymorphic morphologi- (e.g., in the case of I. buschiana Schischik. which can be cally and morphological differences are often obscure, erroneously determined as I. tinctoria L. and I. lusitanica L., Davis, 1965; Hedge, 1968), and thus numerous ÃCorresponding author. Tel.: +98 21 61112482; specimens have to be analyzed for the delimitation of fax: +98 21 66405141. species. Very closely related to Isatis are Pachypterygium E-mail address: [email protected] (S. Zarre). Bunge, Tauscheria Fisch. ex DC., Sameraria Desv. and

0367-2530/$ - see front matter r 2007 Published by Elsevier GmbH. doi:10.1016/j.ﬂora.2006.10.004

Please cite this article as: Moazzeni, H., et al., Seed-coat microsculpturing and its systematic application in Isatis (Brassicaceae) and allied genera in.... Flora (2007), doi:10.1016/j.flora.2006.10.004 ARTICLE IN PRESS 2 H. Moazzeni et al. / Flora ] (]]]]) ]]]–]]] the Central Asian Chartoloma Bunge (not reported thus not congruent with the traditional classification of far from Iran). Most of these genera are placed in the Schulz (1936) based on fruit form. Several lineages in tribe Isatideae by De Candolle (1821), but transferred the molecular tree include Thlaspi species with diverse into Arabideae subtribe Isatidinae by Hayek (1911) and fruit types, whereas species with the same fruit type subsequently into Lepidieae subtribe Isatidinae by belong to different clades, thus providing strong Schulz (1936). The differences between these genera evidence for convergence in fruit traits. Vaughan and are often based on single fruit characters. For example, Whitehouse (1971) investigated the seed-coat anatomy Sameraria differs from Isatis by its distinct (instead of of 200 species of Brassicaceae, but only a few Isatis obsolete) style. The thickened (vs. thin) fruit margin is species have been studied using the scanning electron used to separate Pachypterygium from Isatis (Hedge, microscopy (SEM). 1968). However, some botanists (e.g., Jafri, 1973; The present study is the first to investigate the seed Rechinger, 1958; Sajedi et al., 2005) reduce Pachypter- surface of Isatis and its allies in a taxonomic context. It ygium to synonymy of Isatis and consider the thickened deals with 41 populations of 23 species in four genera of fruit margin not a reliable character to separate these the tribe Isatideae sensu Al-Shehbaz et al. (2006). genera apart. Based strictly on the overall morphology, it is highly likely that the Isatideae sensu Al-Shehbaz (Al-Shehbaz Material and methods et al., 2006) also include the genera Pachypterygium (3 spp.), Sameraria (9 spp.) and the monotypic Boreava Information on the species analyzed, collection data Jaub. & Spach, Chartoloma, Glastaria Boiss., Schimpera and the vouchers used are given in Table 1. Seeds were Hochst. & Steud. ex Endl., Spirorrhynchus Kar. & collected from living plants whenever possible, otherwise Kir. and Tauscheria. Both Myagrum L. and Tauscheria from herbarium specimens. The species belong to Isatis were placed by De Candolle (1821) with Isatis (inclu- (15 of 17 species in Iran), Sameraria (4 of 5 species in ding Sameraria) in the Isatideae. This morphologically Iran), Pachypterygium (all 3 species) and Tauscheria well-defined group of primarily central Asian genera (monotypic, distributed in Iran and neighboring coun- is characterized by having indehiscent, 1- or 2-seeded, tries). Iranian species which are not included in this primarily angustiseptate fruits, yellow or rarely whitish analysis were previously recorded as doubtfully occur- flowers, sessile and often auriculate cauline leaves, ring in Iran, or they are rare or known only from the and simple or no trichomes (Appel and Al-Shehbaz, type collections that possess no seeds. 2003). Preliminary molecular data (Beilstein et al., For the SEM studies, clean seeds were fixed on 2006) show that Isatis and Myagrum (1 sp.) form aluminum stubs using double-sided adhesive and were a monophyletic group (93% bootstrap support), coated with a thin layer (ca. 25 nm) of gold-palladium. sister to a clade including the tribes Brassiceae, The SEM micrographs were taken in a Zeiss SEM-960A Schizopetaleae and Sisymbrieae. However, the (Germany) (Figs. 1–6) or Leo SEM-4401 (England) phylogenic relationships and the delimitation of the (Figs. 7–15) from the middle of the seed, mostly at a Isatideae are still awaiting a comprehensive molecular magnification of 100–700 . At least four seeds from analysis. each specimen were scanned to ensure the consistency of Some of the published accounts on the seed coat of seed-coat characters. For recording gross morphology Brassicaceae (e.g., Barton, 1967) dealt with the species and size parameters, at least 10 seeds were measured. of economic importance (e.g., Brassica L., Sinapis L. Although the terminology of Barthlott (1981) was and Raphanus L.) and were primarily concerned with based on SEM observations of epidermal and seed-coat species identification. Other studies used the ultra- surface in 5000 species of seed plants and has been used structural pattern as a reliable approach for assessing in several studies, we found those of Murley (1951) and phenetic relationships and resolving taxonomic pro- Koul et al. (2000) to be more applicable to the patterns blems in the Brassicaceae (Barthlott, 1981; Bengoechea in Isatis and its relatives: and Go´ mez-Campo, 1975; Bouman, 1975; Buth and Roshan Ara, 1983, 1987; Cˇernohorsky` , 1950; Francois, Colliculate: having small hill-like eminences or 1937; Koul et al., 2000; McCugan, 1948; Meyer, 1973, rounded broad elevations, closely spaced, covering 1979, 1991; Murley, 1951; Musil, 1948; Vaughan and throughout the seed coat (Fig. 4); Whitehouse, 1971). For Thlaspi L., it was clearly Lineolate: marked with broken fine lines (Fig. 7); demonstrated that molecular data (Koch and Mum- Ocellate: having eye-like depressions, each with a menhoff, 2001; Mummenhoff and Koch, 1994; Mum- raised circular border (Figs. 14 and 15); menhoff et al., 1997a, b; Zunk et al., 1996) provide Reticulate: with a reticulum or net and interspaces strong support for the recognition of several segregates characterized with raised walls. The interspaces can as proposed by Meyer (1973, 1979, 1991) based on seed- be distinct (Fig. 8) and relatively large or more or less coat anatomy. The molecular phylogeny of Thlaspi is indistinct and small (Fig. 10);

Table 1. List of taxa, voucher and some characteristic seed features of Isatis and its allies used in the present study

Taxon Place of origin and herbarium Voucher Seed Seed-surface number length pattern (mm)

I. buschiana Kordistan, Bijar to Zanjan, 5 km up to Bianlou 973-KOHa 3.1270.25 Reticulate village I. buschina E Azarbaijan, Zanjan to Tabriz, 20 km to Tabriz 35380-TUH – Reticulate I. kotschyana W Azarbaijan, Sardasht to Mahabal, 65 km to 36098-TUH 4.270.97 Reticulate–areolate Mahabad I. kotschyana Tehran, road of Chalus 35807-TUH – Reticulate–areolate I. kotschyana Kordistan, Saghez, Chehel Cheshmeh mts. 1702-KOH – Reticulate–areolate I. kotschyana Khorassan, Piozhen, Ghar-e Kohneh 23401-FUMH – Reticulate–areolate I. kotschyana W Azarbaijan, 57 km to Uromieh, Qushchi pass 35790-TUH – Reticulate–areolate I. kotschyana Lorestan, Arak to Borojerd, 10 km to Borojerd, 35794-TUH – Reticulate–areolate Hirab I. kotschyana Hamadan, Aqbulaq 15662-IRAN – Reticulate–areolate I. kotschyana W Azarbijan, Maku, Kaveh-ghalij dagh 15662-IRAN – Reticulate–areolate I. campylocarpa Esfahan, 10 km to Golpayegan from Khansar 33754-TUH 2.370.34 Scalariform–areolate I. campylocarpa Esfahan, 10 km to Golpayegan from Khansar 33754-TUH – Undulate I. cappadocica ssp. E Azarbaijan, Mianeh to Gharehchaman, 20 km 35797-TUH 4.570.5 Reticulate–areolate cappadocica to Ghareh-chaman I. cappadocia ssp. Kordistan, Sanandaj to Kamyaran, Awalan mt. 6896-KOH 5.570.82 Reticulate–areolate macrocarpa I. cappadocica ssp. Kordistan, W Sanandaj, Abbydar mt. 1251-KOH 4.570.50 Reticulate–areolate stenophylla I. cappdocica ssp. Kordistan, SW Sanandaj, Dulab pass 6663-KOH 4.570.50 Reticulate–areolate subradiata I. cochlearis E Azarbaijan, Marand, Jolfa, 7 km from Duzhal 5990-TARI 2.770.52 Reticulate–areolate to Asheghlu, margin of Aras river I. cochlearis E Azarbaijan, Marand, Jolfa, 7 km from Duzhal Without – Reticulate–areolate to Asheghlu, margin of Aras river herbarium number-IRAN I. emerginata Khorassan, SW Tabas, Nayband road 24858-FUMH 3570.51 Reticulate–areolate I. gaubae Tehran, Firuzkuh, Shormast spring 35781-TUH 3.170.42 Reticulate–areolate I. gaubae Mazandaran: Versek 38492-IRAN – Reticulate I. leuconeura Khorassan: Shirvan, Hamanlou, Mountain 15687-IRAN 3.070.35 Colliculate Goloul I. lusitanica Markazi, Arak, Emarat 12340-TUH 3.670.39 Ocellate I. minima Semnan, Shahrud to Mayamei, 20 km to Mayamei 35787-TUH 2.870.32 Reticulate–areolate I. minima Kerman, NE Bazman mt. 35765-TUH Reticulate–areolate I. pachycarpa Kerman, Jebal Barez Without 3.770.25 Reticulate herbarium number-IRAN I. raphanifolia Yassuj, 5 km from Dehdasht to Behbahan 20309-TUH 2.370.32 Ocellate I. rugolosa Yazd, Marvest 20720-TUH 2.070.22 Reticulate I. tinctoria Kerman, Laleh Zar mt. 35827-TUH 3.070.28 Reticulate–areolate I. tinctoria Gorgan, Golestan National Park, road of Almeh 5884-TUH – Reticulate–areolate I. tinctoria Kerman, Jebal Barez 35785-TUH – Reticulate–areolate I. tinctoria Khorassan, NE Bojnord, Raz 35779-TUH – Reticulate–areolate I. trachycarpa Semnan, Shahrud to Sabzevar, 147 km to 35754-TUH 2.7570.33 Reticulate Sabzevar I. trachycarpa Khorassan, Torbat-e Jam to border of Harirud 28466-TUH – Reticulate–areolate P. stocksii Khorasan, Sarakhas to Sangerd 15060-FUMH 2.770.3 Reticulate–areolate P. brevipes Tehran, Alborz mountains, Meigum toward 35785-TUH 2.2170.136 Lineolate Shahrestanak P. brevipes Kerman, mts. Jupar 35788-TUH – Lineolate P. multicaule Kerman, Kuhpayeh 35784-TUH 1.9770.136 Lineolate S. armena Khorassan, Torbat-e Jam to border of Harirud 28450-TUH 4.270.63 Reticulate–areolate

Table 1. (continued )

Taxon Place of origin and herbarium Voucher Seed Seed-surface number length pattern (mm)

S. elegans Semnan, Shahrud to Sabzevar, 147 km to 35752-TUH 3.9370.49 Scalariform Sabzevar S. nummularia Tehran, on the road of Chalus, before Tunel 27999-TUH 4.2570.95 Reticulate Kandavan S. stylophora Tehran, Darakeh mts. 29348-TUH 4.7170.99 Reticulate–areolate T. lasiocarpa Khorassan, NE Bojnord, Raz 35793-TUH 2.7270.56 Reticulate–areolate

When the data are lacking due to unavailability of material, it is noted by a dash. aKordestan Herbarium.

Reticulate–areolate: intermediate between reticulate followed by reticulate (7 species) and scalariform–areo- and areolate (composed of circular or polygonal late, lineolate and ocellate pattern (each type with 2 areas separated by grooves) (Fig. 12); species). The remaining four types were represented each Scalariform: small cross-band markings resembling only by a single species (Table 1). the steps of a ladder. Among our specimens, we Although a network of raised lines is a common characterized a type of reticulate pattern consisting of feature of the reticulate type, the species vary in the regular rows of spaces and the raised walls oriented alignment and shape of the network and in the straightly (Fig. 6); architecture of the interspaces enclosed by the raised Scalariform–areolate: intermediate between scalari- walls (Table 2). Similarly, distinct differences in the fine form and areolate (not shown); structure are found among the species with reticula- Undulate: having a wave-like pattern of walls te–areolate type. For example, the cells are larger, separating irregular interspaces (Fig. 5). arranged more regularly, and with much thicker and more elevated walls in I. kotschyana (Table 2) than in either I. cappadocica subsp. cappadocica (Fig. 11) and I. cappadocica subsp. subradiata (Rupr.) Davis (for more Results details see Table 2). Similar differences were observed in I. buschiana showing reticulate type with 7 straight and We found three basic seed shapes: oblong (Fig. 1); narrow walls (Fig. 8; Table 2) compared to I. pachycarpa flattened oblong (Fig. 2) and ellipsoid (Fig. 3). The first (Fig. 9; Table 2) with undulated and thicker cell walls. and third shapes were most common, and the flattened Such structures in S. nummularia (Fig. 10) can also be oblong type was characteristic for and unique to Isatis used for its separation from I. buschiana (Fig. 8). raphanifolia Boiss. Although two subspecies of I. cappadocica subsp. The spectrum of seed length ranges from 1.97 to subradiata and I. cappadocica subsp. macrocarpa (Jaub. 5.50 mm in Pachypterygium multicaule (Kar. & Kir.) & Spach) Davis show the reticulate–areolate type of Bunge and I. kotschyana Boiss. & Hohen., respectively. seed coat, they differed in the alignment and nature of The seed-surface sculpturing pattern is classified in the cells (see Table 2). eight types (Figs. 4–15; Table 1): The most common is the Tauscheria lasiocarpa Fisch. ex DC. (Fig. 13) has the reticulate–areolate type, for example in Isatis kotschyana, same type of seed coat as I. kotschyana. Thus, it cannot I. cappadocica subsp. cappadocica (Fig. 11), I. tinctoria, I. be separated by characters of the seed-coat surface. gaubae Bornm., I. minima Bunge (Fig. 12), and I. Pachypterygium shows two types of seed-coat pattern: emarginata Boiss. The reticulate type occurs in species P. brevipes (Fig. 7)andP. multicaule have lineolate such as I. pachycarpa Rech.f., Aellen & Esfand. (Fig. 9), surfaces, while P. stocksii (Boiss.) Hedge belongs to the I. trachycarpa Trautv. and I. rugulosa Bunge ex Boiss. reticulate–areolate type. The first two are indistinguish- The other types are the lineolate, as in Pachypterygium able by seed-coat traits. In Sameraria, the common seed- brevipes Bunge (Fig. 7); scalariform–areolate, as in I. coat type is reticulate–areolate, but the species show cochlearis Boiss. and I. campylocarpa Boiss.; ocellate, as differences in cell alignment and shape (see Table 2). in I. lusitanica (Fig. 14)andI. raphanifolia (Fig. 15); Sameraria armena (L.) Desv. differs from S. stylophora scalariform, as in Sameraria elegans Boiss. (Fig. 6); (Jaub. & Spach) Boiss. in having regularly arranged and undulate, as in I. campylocarpa (Fig. 5), colliculate, as in thick-walled cells, and in S. armena the cells are less I. leuconeura Boiss. & Buhse (Fig. 4). The majority (15) of regularly arranged compared to S. elegans (Fig. 6; see the species studied show the reticulate–areolate pattern, also Table 2).

Fig. 1–3. Basic seed shape types: (1) Isatis cappadocica subsp. subradiata as oblong. (2) I. raphanifolia, as ﬂattened oblong and (3) Pachypterygium multicaule, as narrowly elliptic. 4–15. SEM micrographs of seed-coat microsculpturing of Isatis and allied genera. (4) Isatis leuconeura,(5) I. campylocarpa,(6) Sameraria elegans, (7) Pachypterygium brevipes,(8) I. buschiana,(9) I. pachycarpa,(10) S. nummularia,(11) I. cappadocica subsp. cappadocica,(12) I. minima,(13) Tauscheria lasiocarpa,(14) I. lusitanica,(15) I. raphanifolia,(1) scale bar ¼ 1 mm; (2 and 3) scale bar ¼ 0.4 mm; (4–6) scale bar ¼ 40 mm; (7, 9–15) scale bar ¼ 20 mm; (8) scale bar ¼ 30 mm.

Discussion (Barthlott, 1981; Koul et al., 2000; Murley, 1951; Vaughan and Whitehouse, 1971), and such studies were Seed-coat sculpturing patterns and seed-coat anatomy lacking on Isatis and its allies. Only I. tinctoria was have been shown to provide valuable characters in recorded to have puncticulate to rough surfaces delimitation of taxa in selected groups of Brassicaceae (Murley, 1951) based on gross morphology of the seeds.

Table 2. Some microsculpturing features in taxa of Isatideae studied here showing the reticulate and reticulate–areolate types of seed coat pattern

Taxa Microsculpturing features

Reticulum Reticulum wall

Compact Lax 5–6 side Sharply angled Narrow Undulated Smooth Broken

Isatis buschiana (No. 973-KOH) + ++ I. buschiana (No. 35380-TUH) 7 + + + I. campylocarpa ++ + + I. cappadocica subsp. cappadocica 7 + ++ I. cappadocica subsp. macrocarpa ++ + I. cappadocica subsp. stenophylla ++ + I. cappadocica subsp. subradiata ++++ + I. cochlearis + + + I. gaubae (No. 35781-TUH) + ++ I. gaubae (No. 38492-IRAN) ++ I. gaubae (No. 38492-IRAN) + + + I. kotschyana (No. 35807-TUH) + + I. kotschyana (No. 1702-KOH) + + + I. kotschyana (No. 23401-FUMH) + + + I. kotschyana (No. 35790-TUH) + ++ I. kotschyana (No. 35794-TUH) + + + I. kotschyana (No. 15662-IRAN) + + I. minima (No. 35787-TUH) + ++ + I. minima (No. 35765-TUH) + ++ + I. pachycarpa + ++ I. rugulosa + + I. tinctoria (No. 35827-TUH) + + + I. tinctoria (No. 5884-TUH) + + + I. tinctoria (No. 35785-TUH) + + ++ I. tinctoria (No. 35779-TUH) + + ++ I. trachycarpa (No. 35754-TUH) + + + I. trachycarpa (No. 28466-TUH) + + Pachypterygium stocksii + + + Sameraria armena + + S. elegans + + S. nummularia + + + S. stylophora + ++ Tauscheria lasiocarpa ++ ++ +

If several specimens were studied, they are indicated by herbarium number and the herbarium abbreviation (see Table 1) after the name of taxon.

However, the ultra-structural studies presented here Isatideae sensu Al-Shehbaz et al. (2006). Vaughan revealed that its surface is reticulate–areolate. Although and Whitehouse (1971) showed that aspects of seed- the reticulate–areolate type of seed-surface sculpturing is coat anatomy did not reﬂect phylogenetic relationships more common among the species studied, it cannot be and, therefore, they are homoplasious just as the considered as a characteristic feature of Isatis and its morphological characters referred to by Al-Shehbaz allies, because it is also frequently present in many et al. (2006). unrelated genera including Brassica (Koul et al., 2000). Microsculpturing of the seed surface, however, reveals Moreover, some rare sculpturing types like the ocellate clear differences among several taxa studied here. Based type, known in few taxa of Brassicaceae, e.g., Brassica on the eight main types of seed-coat patterns it is gravinae Ten. (Koul et al., 2000) and Conringia orientalis possible to distinguish the species. Furthermore, the ﬁne (L.) Andrz. (Murley, 1951), are also present in certain structure of the seed surface is almost constant among species studied here. Therefore, it seems that seed- different populations of a given species and shows little surface sculpturing does not provide reliable characters variation. Interestingly, all four different subspecies of useful for the delimitation of the genera within the the highly polymorphic Isatis cappadocica (Davis, 1965;

Hedge, 1968) examined here uniformly show the (Al-Shehbaz et al., 2006) and not as a member of the reticulate–areolate type of seed surface. Euclidieae (Schulz, 1936). The ocellate type is found in Isatis lusitanica (Fig. 14) In conclusion, seed-coat morphology provides strong and I. raphanifolia (Fig. 15) which are closely related support for the delimitation of several taxa in the based on both morphological and molecular analyses Isatideae, especially at the specific level, but the (Moazzeni et al., unpublished data). As another significance of these characters in delimitation of natural characteristic sculpturing type, the colliculate one is groups at the generic or subgeneric level remains unclear observed in I. leuconeura (Fig. 4). However, I. cochlearis, and awaits further studies that include additional taxa its closest relative as suggested by Hedge (1968) and distributed outside of Iran. Moreover, the evaluation of Sajedi et al. (2005), shows the reticulate–areolate phylogenetic significance of micromorphological seed- surface. Therefore, the present grouping of species based coat characters in Isatis and allies by a molecular on seed-coat variation is inconsistent with earlier phylogenetic approach, as has been done successfully in morphological studies. Thlaspi, is currently under study. Among all species of Pachypterygium is characterized by having a thick- Isatis, only I. tinctoria has been previously considered in ened fruit rim and small habit, though these characters the molecular phylogeny of Brassicaceae (Beilstein et al., are also shared by some annual species of Isatis like I. 2006). A more detailed analysis including several species trachycarpa. Judged from characters of the seed surface, of Isatis will clarify the systematic relationships within P. brevipes (Fig. 7) and P. multicaule are lineolate, a this interesting genus. type not shown by any Isatis species. However, Pachyperygium stocksii and I. trachycarpa, which show considerable morphological similarities, have the reticulate–areolate type. This perhaps supports the retention Acknowledgments of P. stocksii as a species of Isatis rather than placing it in Pachypterygium, as was done by Jafri (1973). Species The authors are indebted to anonymous referees for of Pachypterygium have the smallest seeds among the their substantial revising and improving of the text. taxa studied here, but some annual species of Isatis like Special thanks go to A.R. Khossravi (Shiraz University) I. rugulosa and I. campylocarpa show almost a similar for his valuable suggestions and comments on the seed size. manuscript. We are grateful to M. Mirtajedini (Kerman The 4 species of Sameraria studied here can be University), M. Joharchi (Mashahd University) and H. classified in three types by seed-surface sculpturing Maroofi (Research Institute of Forests and Rangelands patterns. Sameraria armena and S. stylophora have two of Kordestan) for providing herbarium material of very different silicle types: with two or four wings, several species, to S. Sajedi (Research Institute of Pests respectively, but both show the reticulate–areolate type and Diseases, Tehran) for her valuable suggestions and of seed surface. Sameraria elegans (Fig. 6) has the to S.M.H. Hashemi (University of Tehran) and Mrs. scalariform type, and S. nummularia (Fig. 10) has the Eshghi (Azad Islamic University) for their assistance in reticulate type of seed surface. Based on fruit morphol- preparing SEM micrographs. The study was supported ogy (presence of two or four wings), S. armena is related in part by the Research Council of Tehran University. to S. elegans, and S. nummularia to S. stylophora. Therefore, the seed-surface sculpturing in Sameraria does not confirm the affinities among species based on References fruit morphology and petal size. The petals are 2.54 mm long in the former species, while 4.56mm Al-Shehbaz, I.A., Beilstein, M.A., Kellog, E.A., 2006. Sys- in the latter. Based on fruit types also in both former tematics and phylogeny of the Brassicaceae (Cruciferae): an species the silicles are two winged, but in the latter they overview. In: Koch, M.A., Mummenhoff, K. (Eds.), are four winged. However, it is confirmed that there are Evolution and Phylogeny of Brassicaceae. Pl. Syst. Evol. often other character types superior to fruit characters Special Vol. Springer, Berlin, Heidelberg, pp. 89–120. in Brassicaceae. A convincing example is Meyers’ (1973, Appel, O., Al-Shehbaz, I.A., 2003. Cruciferae. In: Kubitzki, K. 1979, 1991) works on seed-coat anatomy in Thlaspi, (Ed.), Families and Genera of Vascular Plants, Vol. 5. contradicting the systems based on fruit characters and Springer, Berlin-Heidelberg, pp. 75–174. strongly corroborated later on by the molecular analyses Barthlott, W., 1981. Epidermal and seed surface characters of plants: systematic applicability and some evolutionary (Koch and Mummenhoff, 2001). aspects. Nord. J. Bot. 1, 345–355. Although Tauscheria is unique in the Isatideae by Barton, L.V., 1967. Bibliography of Seeds. Columbia Uni- having fruits with curved beaks and distinctly convex versity Press, New York, London. lower side, its reticulate–areolate seed surface is the Beilstein, M.A., Al-Shehbaz, I.A., Kellogg, E.A., 2006. most common in the tribe. Our results agree with Brassicaceae, phylogeny and trichome evolution. Am. J. the placement of Tauscheria within the Isatideae Bot. 93, 607–619.

Bengoechea, G., Go´ mez-Campo, C., 1975. Algunos ca´ racteres Meyer, F.K., 1973. Conspectus der ‘‘Thlaspi’’-Arten Europas, de la similla en la tribu Brassiceae. Ann. Inst. Bot. Afrikas und Vorderasiens. Feddes Repert. 84, 449–470. Cavanilles 32, 793–841. Meyer, F.K., 1979. Kritische Revision der ‘‘Thlaspi’’-Arten Bouman, F., 1975. Integument initiation and testa develop- Europas, Afrikas und Vordersaiens I. Geschichte, Mor- ment in some Cruciferae. Bot. J. Linn. Soc. 70, 213–299. phologie und Chorologie. Feddes Repert. 90, 129–154. Buth, G.M., Roshan Ara, N.A., 1983. Seed coat anatomy of Meyer, F.K., 1991. Seed-coat anatomy as a character for a new some cultivated Brassica. Phytomorphology 31, 69–78. classification of Thlaspi. Fl. Veg. Mundi 9, 9–15. Buth, G.M., Roshan Ara, N.A., 1987. Seed and seed coat Mummenhoff, K., Koch, M, 1994. Chloroplast DNA restric- anatomy of the some members of tribe Arabideae tion site variation and phylogenetic relationships in the (Brassicaceae). Phytomorphology 37, 341–348. genus Thlaspi sensu lato (Brassicaceae). Syst. Bot. 19, ˇ Cernohorsky` , Z., 1950. Anatomie des graines des espe´ ces 73–88. tche´ ques du genre Thlaspi L. Bull. Int. Cl. Sci. Math. Nat. Mummenhoff, K., Franzke, A., Koch, M., 1997a. Molecular Med. Acad. Tche´ que Sci. 47, 5–10. phylogenetics of Thlaspi (Brassicaceae) based on chloro- Davis, P.H., 1965. Isatis. In: Davis, P.H. (Ed.), Flora of plast DNA restriction site variation and sequences of the Turkey and the East Aegean Islands, Vol. 1. Edinburgh internal transcribed spacers of nuclear ribosomal DNA. University Press, Edinburgh, pp. 1–567. Can. J. Bot. 75, 469–482. De Candolle, A.P., 1821. Prodromus Systematis Naturalis Mummenhoff, K., Franzke, A., Koch, M., 1997b. Molecular Regni Vegetabilis, Vol. 1. Sumptibus Victoris Masson, data reveal convergence in fruit characters used in the Parisiis, pp. 131–236. classification of Thlaspi s.l. (Brassicaceae). Bot. J. Linn. Francois, L., 1937. Semences et junes plantes des vegetaux Soc. 125, 183–199. messicoles; famille des Crucife´ res. Ann. Epiphyt. 3, 8–21. Murley, M.R., 1951. Seeds of the Cruciferae of the North Hayek, A.V., 1911. Entwurf eines Cruciferen-Systems auf Eastern America. Am. Midl. Nat. 46, 1–81. phylogenetischer Grundlage. Beih. Bot. Centralbl. 27, Musil, A.F., 1948. Distinguishing the species of Brassica by 127–335. Hedge, I.C., 1968. Lepidieae. In: Rechinger, K.-H. (Ed.), Flora their seeds. US Dept. Agric. Misc. Publ. no. 643. Iranica, Vol. 57. Akademische Druck- und Verlagsanstalt, Rechinger, K.H., 1958. Cruciferae. In: Køeie, M., Rechinger, K.H. Graz, pp. 63–122. (Eds.),SymbolaeAfghanicaeIV.Biol.Skr.Dan.Vid.Selsk, Jafri, S.M.H., 1973. Brassicaceae. In: Nasir, E., Ali, S.I. (Eds.), Vol. 10, pp. 13–54. Flora of West Pakistan, Vol. 55. University of Karachi, Sajedi, S., Sharifnia, F., Assadi, M., 2005. A study of the genus Karachi, pp. 1–308. Isatis in Iran. Rostaniha 6, 47–66 (In Persian). Koch, M., Mummenhoff, K., 2001. Thlaspi s.str. (Brassica- Schulz, O.E., 1936. Cruciferae. In: Engler, A., Prantl, K. ceae) versus Thlaspi s.l.: morphological and anatomical (Eds.), Die natu¨ rlichen Pflanzenfamilien, 17b. W. Engel- characters in the light of molecular data. Plant Syst. Evol. mann, Leipzig, pp. 227–685. 227, 209–225. Vaughan, J.G., Whitehouse, J.M., 1971. Seed structure and the Koul, K.K., Nagpal, R., Raina, S.N., 2000. Seed coat taxonomy of Cruciferae. Bot. J. Linn. Soc. 64, 383–409. microsculpturing in Brassica and allied genera (subtribe Zunk, K., Mummenhoff, K., Koch, M., Hurka, H., 1996. Brassicinae, Raphaninae, Moricandiinae). Ann. Bot. 86, Phylogenetic relationships of Thlaspi s.l. (subtribe Thlaspi- 385–397. dinae, Lepidieae) and allied genera based on chloroplast McCugan, J.M., 1948. Seeds and seedlings of the genus DNA restriction site variation. Theor. Appl. Genet. 92, Brassica. Can. J. Plant Res. 26, 520–587. 375–381.