Acta Botanica 1-2017 - za web.indd ACTA BOT. CROAT. 76 (1), 2017 27 Acta Bot. Croat. 76 (1), 27–31, 2017 CODEN: ABCRA 25 DOI: 10.1515/botcro-2016-0052 ISSN 0365-0588 eISSN 1847-8476 A morphological study on the dioecious endemic Erodium somanum H. Peşmen (Geraniaceae), critically endangered in Turkey Dilek Oskay* Celal Bayar University, Faculty of Science and Arts, Department of Biology, Manisa, Turkey Abstract – Morphological features of the endemic Erodium somanum are investigated based on the speci- mens collected from natural populations from Soma in Manisa. Almost all morphological characteristics are expanded and some morphological characteristics are fi rstly determined in this study. E. somanum is a dioe- cious species and in this study drawings of male and female individuals are given for the fi rst time. An umbel is 3–5 fl owered in female plants and 6–11 fl owered in male plants, pedicels accrescent to 20–25 mm in fruit. Flower morphology was identifi ed in detail and drawings are given for the fi rst time. Stigma color ranges from yellow to red in populations. The fruit is long-beaked 4.8–8 cm, stout and adpressed pilose, glandular below. Mericarp morphology investigated for fruit characters has a special diagnostic value for systematic studies. The mericarp micromorphology and seed micromorphology were determined for the fi rst time. Meri- carp size 9–12 mm, mericarps have two apical shallow pits (foveoles) without furrow beneath. Mericarp sur- face ornamentation is foveate with crowded bristles of dissimilar size, some longer and others shorter. Meri- carp pit is crowded with eglandular hairs and some sparse, long-stalked glands which are also at the start of the awn. Seed size is 4.5–6×1.5–2 mm, seed type is narrowly ovate, seed surface is ruminate. Keywords: dioecious plant, endangered endemic plant, Erodium somanum, fl ower morphology, micromor- phology. * Corresponding author, e-mail: dilek.oskay@cbu.edu.tr Introduction Geraniaceae have fi ve genera characterized by their fl ower features, Erodium, Geranium, Monsonia, Sarcocau- lon, Pelargonium (Takhtajan 1997). A sixth genus, Califor- nia, has been segregated from Erodium primarily because of the absence of staminodes (Aldasoro et al. 2002). The genus Erodium is distributed across all continents. A major center of diversity is in the Mediterranean region (63 spe- cies), whereas in other regions only a few native species have been observed; North America (1), South America (1), Australia (5), and Asia (4) (Fiz et al. 2006). The fi rst revi- sion of Erodium species in Turkey and the East Aegean Is- lands was made by Davis who recognized 27 taxa (Davis 1967). Since then, fi ve new species have been described (Davis et al. 1988, Güner et al. 2000, Yıldırımlı and Doğru- Koca 2004) and the total has now reached 32 taxa. Sixteen of these Erodium taxa are endemic in Turkey. Erodium somanum H. Peşmen is an endemic species known from Soma in Manisa, west of Turkey (Davis et al. 1988). It was reported that E. somanum, in terms of general appearance is similar to Erodium sibthorpianum Boiss. sub- sp. sibthorpianum and Erodium absinthoides Willd. subsp. absinthoides. But E. somanum is clearly different from E. sibthorpianum subsp. sibthorpianum in that it has less ca- nescent leaves, lilac petals and a shorter (3.5–4.5 cm) beak to the fruit; also E. somanum is clearly different from E. absinthoides subsp. absinthoides in that it has lax rosettes, white petals and a longer (2–2.8 mm) sepal mucro (Davis et al. 1988). Then, it was seen that a new combination had been made as Erodium sibthorpianum Boiss. var. somanum (Peşmen) El-Oqlah (El-Oqlah 1989). Moreover, it was seen that a new name Erodium chrysanthum subsp. somanum had been given but the new name of the author was not pro- vided (Fiz et al. 2006). As shown there are contradictions in the nomenclature of this species. To overcome confusion in this regard, it seems that a detailed study about the species mentioned is needed. In this study, E. somanum was used because of the fi rst name given to the type specimen. This species was fi rst classifi ed into the Endangered (En) catego- ry based on IUCN criteria (Ekim et al. 2000) and later clas- sifi ed as Critically Endangered (CR) according to data ob- tained from population studies and based on IUCN criteria (Oskay and Altan 2015). OSKAY D. 28 ACTA BOT. CROAT. 76 (1), 2017 E. somanum naturally grows in rocky habitats, above 800 m, after the tree line. Total distribution area of popula- tions is approximately 5 km2, in the surroundings of the east-west extension of Güllük Mountains in Soma. Distri- bution soils are slightly alkaline, without salt and a gener- ally limey structure, adequately ferrous but poor in phos- phor. Climate type is semi-arid upper Mediterranean where the winters in particular are cool (Oskay and Altan 2015). Studies on its morphology are limited. Pollen features and chromosome numbers of E. somanum have been inves- tigated (Oskay et al. 2011). The present study is aimed at expanding morphological descriptions of this endemic spe- cies, including its detailed fl oral features. Mericarp surface is a very important diagnostic character for Erodium spe- cies; mericarp and seed surface have been investigated and scanning electron microscopy (SEM) photos are given fi rst time in this study. Material and methods E. somanum was collected from natural populations during a project supported by Scientifi c Research Projects from Celal Bayar University. The specimens are dried ac- cording to standard herbarium techniques and stored at Celal Bayar University Science and Education Faculty. The taxonomical description of the plants was made ac- cording to E. somanum in “Flora of Turkey Vol. 10” by Da- vis et al. (1988). For the morphological studies, dried sam- ples were used. Specifi c characters were measured at least twenty times. Photographs and drawings with general views of the male and female individuals, fl ower parts and fruit have been added to the study because it is a dioecious species. All measurements with fruit and seed were made at least thirty times. Fruit and seed were also directly placed on prepared stubs and covered with gold for micromorpho- logical features by SEM. Photographs are taken with a Jeol JSM 6060. For fruit terminology the following literature was consulted (Davis 1967, Fiz et al. 2006). Seed terminol- ogy from the following literature was consulted (Stearn 1996). Results Morphology of vegetative parts E. somanum is a dioecious perennial plant (Fig. 1, On- line Suppl. Fig. 1, On-line Suppl. Fig. 2). Plant populations consist of female and male individuals. Plants are very wide hard cushions up to 60 cm diameter. Rootstock is vertical, woody and black colored. Basal leaves are bipinnatisect, oblong elliptic, 6–16×15–37 mm with 4–20 mm petiole. Leaves are 3–5 segments, linear, acute, adpressed eglandu- lar pubescent with stipules. Stems are erect, 1.3–19.5 cm (excluding peduncules) and simple or scarcely branched, covered with folded mixed villi, bearing 2–4 peduncules. Peduncules are 12–70 mm eglandular hirsute and have stip- itate glands. The umbel infl orescences have 3–5 fl owers in female plants and 6–11 fl owers in male plants. Umbels are multibracteate and bracts are pale grey. Pedicels are very slender, 8–20 mm (accrescent to 20–25 mm in fruit) and glandular pubescent. Morphology of reproductive parts There are two types of fl owers in E. somanum. Female plants have only female fl owers while male plants have only male fl owers. The fl owers are medium size, actino- morphic corolla and borne in bracteate umbels. E. soma- num have pentamerous fl owers consisting of fi ve sepals, fi ve petals, fi ve antipetalous nectaries and fi ve staminodes. Five fertile stamens and fi ve staminodes enclose the vesti- gial gynoecium in male fl owers while fi ve vestigial stamens and fi ve staminodes enclose a gynoecium with fi ve carpels in female fl owers (On-line Suppl. Fig. 3). Petals are pale sulphur yellow in colour, broadly obovate, 3–8×6.5–12 mm, pilose towards base. Petal veins are usually darker than the rest of the petal (Fig. 2). Sepals appearance is transparent, sepal veins are usually green and darker than the rest of the sepal (Fig. 2). Sepal shape is oblong-elliptic, 2–5×4–8 mm (accrescent to 4–8×10–14 mm in fruit), obtuse with 0.5–1.5 mm mucro (On-line Suppl. Fig. 4). Dorsal part of sepal is covered with dense stipitate glands and eglandular villose. The sepals are not deciduous after fruit formation. The syn- Fig. 1. General appearance of Erodium somanum in nature. Fig. 2. Reproductive parts of Erodium somanum: (A, B) Female fl owers; (C) Nectaria and pistil in female fl owers; (D, E) Male fl owers; (F) Nectaria and stamens in male fl owers. A MORPHOLOGICAL STUDY ON ERODIUM SOMANUM ACTA BOT. CROAT. 76 (1), 2017 29 carpous ovary has fi ve carpels, with each chamber having a single ovule with basal placentation. The long style is ter- minated by fi ve furcated stigmas. Stigma color ranges from yellow to red in populations. The stamens are antisepalous, extrorse and versatile. Anthers are two-celled and opened longitudinally. Fruit type is a schizocarp and it is divided into fi ve mericarps (Fig. 3, On-line Suppl. Fig. 4). Fruit is long- beaked with beak 4.8–8 cm long, stout and adpressed pi- lose, glandular below. The outer part of the style separates into fi ve long awns that usually remain attached to the meri- carps. Awns are spirally twisted below and rarely decidu- ous. Mericarp is sized 9–12 mm and is light brown with whitish bristles (Fig. 3). Mericarps have two apical shallow pits (foveoles) without a furrow beneath. Mericarp awn is not plumose. Mericarp surface ornamentation is foveate with crowded bristles of dissimilar size, some longer and others shorter (Fig. 4). Mericarp pit is crowded with eglan- dular hairs and some sparse, long-stalked glands which are also at the start of the awn (Fig. 4). Seed is glabrous, light brown-dark green brown (Fig. 5A). Seed is 4.5–6 mm long and 1.5–2 mm wide, seed shape is oblanceolate, almost terete, dorsal section of the seed is plain, ventral section of the seed is slightly swollen. Apex of the seed is rounded. Hilum not recessed and is clearly evident. Hilum is linear and sub basal, in other words extending upwards from the base of the seed. When SEM photographs of seed surface are examined, it is deter- mined to be ruminate (Figs. 5B, C) according to the follow- ing literature (Stearn 1996). Discussion E. somanum, a critically endangered endemic species in Turkey, was investigated morphologically in the present study in order to contribute to the description and to eluci- date some morphological details. The taxonomical descrip- tion was carried out according to E. somanum in “Flora of Turkey” by Davis et al. (1988). Almost all morphological characteristics are expanded and some morphological char- acteristics, such as mericarp micromorphology, seed micro- morphology and fl ower morphology are determined for the fi rst time. Mericarp morphology investigated for fruit char- acters has a particular diagnostic value for systematic stud- ies. Some differences were found in the morphological characteristic from the description of the taxon in “Flora of Turkey” by Davis et al. (1988). These differences are shown in Table 1. The differences in this study occur because of the goal behind the assessment, the number of samples in- vestigated, the greater time devoted to the task and spent on the related fi eld work. In addition, climatic conditions vary from year to year and may affect the adaptation of plants. This plant is an example of dioecious species, so female and male fl owers morphology were identifi ed in detail and drawings are given for the fi rst time. Some differences were found (Tab. 1) in the fl ower characters from the description of the taxon (Davis et al. 1988). Some characteristics are new fi ndings: there are fi ve fertile stamens and fi ve stami- nodes that enclose the vestigial gynoecium in male fl owers and fi ve vestigial stamens and fi ve staminodes that enclose a gynoecium with fi ve carpels in female fl owers; the petal veins are usually darker than the rest of the petal; sepals are transparent; sepal veins are usually green and darker than the rest of the sepal; dorsal part of sepals covered with dense stipitate glands and are eglandular villous; the sepals Fig. 3. Fruit (A) and mericarp (B) of Erodium somanum. Fig. 4. Scanning electron microscopy photographs of Erodium so- manum mericarps: (A) mericarp surface; (B) long and short bris- tles; (C) glandular hairs; (D) foveoate surface ornamentation. Fig. 5. Seeds of Erodium somanum: (A) General view; (B, C) Scan ning electron microscopy photographs of seed surface at dif- ferent magnifi cation. OSKAY D. 30 ACTA BOT. CROAT. 76 (1), 2017 are not deciduous after the fruit formation; stigma color ranges from yellow to red in populations. The phylogenetic relationships and evolution in Erodi- um have been described according to gene sequences by Fiz et al. (2006). This work is very important in the sense that 74 Erodium taxa have been collected from all over the world. The morphological characters used in the phyloge- netic analyses of authors are noteworthy because about half of these characters are mericarp features. We have benefi ted from this work and from the “Flora of Turkey” when evalu- ating the characters of the mericarp. It was reported that mericarps were hispid, not foveolate, in the “Flora of Tur- key” (Davis et al. 1988). In contrast, the results of this study show that mericarps are hispid but there are two quite shal- low apical pits (foveoles) and these pits are densely hispid (Tab. 1). Approximately 32 Erodium taxa are distributed in Tur- key; however the micromorphology of most species has not been investigated. Micromorphological investigations on the mericarp of some annual taxa of Erodium were con- ducted by Oskay and Eş (2015) who ascertained the meri- carp micromorphology of E. hoefftianum C.A. Meyer, E. botrys (Cav.) Bertol, E. malacoides (L.) L’Hérit, E. mos- chatum (L.) L’Hérit, E. cicutarium (L.) L’Hérit, sub sp. ci- cutarium, E. ciconium (L.) L’Hérit taxa. Authors investi- gated several fruit characters of Erodium species, such as fruit type, length of fruit, length of mericarp, form of meri- carp apex (presenting pits, ridges or furrows), and glandu- lose structures (glands, glandular hairs and papilles) and found signifi cant differences between species. In a study by Coşkunçelebi et al. (2012) E. hendrikii, a closely related taxon to E. malacoides, was compared with respect to char- acters of basal leaves, stem indumentum, trichome type on mericarp surface, petal colour, sepal length, beak of fruit and mericarp. And so these two closely related taxa were separated thanks to the new fi ndings. There is no detailed information about seed microsculp- turing in Erodium species. Seed macro and micro morpho- logical characters of 19 taxa belonging to the family Gera- niaceae were investigated by Ather et al. (2012). They found data that could be useful in providing additional in- formation for taxonomic delimitation at various levels. Also they stated that the morphological and phylogenetic rela- tionship of the taxa within the family Geraniaceae corre- lates well with seed morphological data. The fi ndings of seed characteristics in this study are compared with the fi ndings of seed characteristics by Ather et al. (2012), and it is seen that E. somanum has its own distinct characters. In conclusion, in this study we aimed to introduce mor- phological details of the endemic E. somanum, a perennial dioecious plant species. The morphological features of the investigated taxon were quite similar to those reported by Davis et al. (1988) in “Flora of Turkey”. However, morpho- logical fi ndings concerning the reproductive parts of E. so- manum are, with some exceptions, presented for the fi rst time. Acknowledgements I would like to thank Scientifi c Research Projects from Celal Bayar University (Project Number: FEF–2007–12) for the fi nancial support. I also would like to thank Dr. Cem Azeri for illustrations. Tab. 1. Comparison of plant characters of Erodium somanum. 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