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ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Sendtnera = vorm. Mitt. Bot. Sammlung München Jahr/Year: 1994 Band/Volume: 2 Autor(en)/Author(s): Akhani Hossein, Förther H. Artikel/Article: The genus Heliotropium L. (Boraginaceae) in Flora Iranica Area 187-276 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/;187 www.biologiezentrum.at The genus Heliotropium L. (Boraginaceae) in Flora Iranica Area by H. Akhani & H. Further Abstract: Akham, H. &. Further, H.: The genus Heliotropium L. (Boraginaceae) in Flora Iranica Area. Sendtnera2: 187-276. 1994. ISSN 0944-0178. A revision of the genus Heliotropium L. {Boraginaceae) in Flora Iranica Area based on examination of rich herbarium material and intensive field studies in Iran is presented. Taxonomic characters, an identification key for all accepted taxa, descriptions of species including reference to synonyms and types, enumeration of studied material, notes on taxonomy and variability in morphology, and in most cases illustrations of the flowers and partly entire plants are given. Altogether 37 species with 4 subspecies are accepted for that area. Two new combinations [H. aucheri DC. subsp. carmanicum (Bunge) Akhani &. Förther and H. dasycarpum Ledeb. subsp. transoxanum (Bunge) Akhani & Förther] are established. Most of the taxa are typified. In spite of two recently published new species the total number of species is reduced to about half of the formerly reported within Flora Iranica. Zusammenfassung: Eine Revision der Gattung Heliotropium L. (Boraginaceae), basierend auf der Untersuchung umfangreichen Herbarmaterials und auf Feldstudien im Iran, wird für das Flora Iranica-Gebiet vorgelegt. Taxonomische Merkmale, ein Bestimmungsschlüssel für alle akzeptierten Sippen, Beschreibungen der Taxa mit Angabe von Synonymic und Typen, eine Auflistung des untersuchten Materials, Anmerkungen zur Taxonomie und morphologischen Variabilität, zum Teil Zeichnungen von Blütendetails und vom Habitus der Arten werden präsentiert. Insgesamt werden 37 Arten mit 4 Unterarten für das Gebiet unterschieden. Zwei neue Kombinationen [H. aucheri DC. subsp. carmanicum (Bunge) Akhani & Förther, H. dasycarpum Ledeb. subsp. transoxanum (Bunge) Akhani & Förther] werden erstellt. Die meisten Taxa werden typifiziert. Obwohl erst vor kurzem zwei neu beschriebene Arten hinzukamen, konnte die Gesamtzahl auf etwa die Hälfte der bisher in der Flora Iranica genannten Arten reduziert werden. 1. Introduction The genus Heliotropium is the largest and most complex genus of Boraginaceae in Flora Iranica Area. Most of the species are growing in arid and semi-arid habitats. The treatment of this genus in Flora Iranica (RiEDL 1967) has not sufificently solved the difficult taxonomic situation. Some of the species dealed there were reported only on base of literature and misidentified herbarium specimens. Most of the previously described species were uncritically accepted without consideration of their correct taxonomical position. Therefore the reported number of 74 Heliotropium species from Flora Iranica Area is liiglily exaggerated. Since publication of Flora Iranica more than 12 additional species were described or shown from that area (Riedl 1968; Kazmi 1970; PONERT 1973; Rechinger 1976; RiEDL & ESFANDIARI 1976; © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/;188 www.biologiezentrum.at ESFANDIARI 1977; Kunkel 1977; RECHINGER & WENDELBO 1977; RIEDL 1977; LEONARD 1984; RECHINGER & WENDELBO 1985; Nasir 1987; Akhani 1991a; AKHANI& Riedl 1991). The presented study is based on intensive field studies in Iran and examination of a large amount of herbarium and type material fi-om various European and Iranian herbaria. In order to typify the genus and its sections most of the original type material has been examined. Consulted herbaria are abbreviated according the S^h edition of Index Herbariorum (HOLMGREN & al. 1990): B, BM, BP, BR, FR, G, GOET, H, HAL, HOH, IRAN, JE, K, KAS, L, LE, M, MEL, P, PR, PRC, STU, TARI, TEH, TUB, TUH, W, WAG, WU, *MMTT (Natural History Museum of Iran), *MUH (Mashahd University Herbarium), *SBUH (Shahid Beheshti University Herbarium), and private Herbarium of Prof PODLECH (München) and Akhani. Those Iranian herbaria which are not yet included in Index Herbariorum are marked above with an asterisk (*). Additional information by the authors to the cited herbarium material is given in brackets [..]. Working in the fields many of the complex groups were studied in their natural habitats, in some very critical cases additionally at the original type localities. According to this investi- gation a lot of species are recognized only as synonyms for others or reduced in rank of infi-a- specific taxa. This account is presenting the taxonomic characters, a new identification key of all accepted taxa, descriptions including declaration of type specimens. Additionally a Hst of synonyms, a selection of studied material, notes on taxonomy, typification and the habitats of the species, and many detailed illustrations of flowers and partly plant habits are given. 2. Taxonomic characters One of the biggest problems in taxonomy of the genus Heliotropium is the large variability in morphological characters. Many of them are strongly influenced by ecological conditions as well as by individual life cycles of the plants. The presented analysis led the authors to the conclusion that a lot of taxonomic characters formerly used by the two main works on this genus in Flora Iranica Area (BUNGE 1869; RiEDL 1967) seem to have much less importance in distinguishing of species and infi-ageneric classification of the genus. A good example of morphological variabilities inside this genus has been given by BRUMMITT (1971) for the few European species. The mainly used taxonomic characters of this work result fi'om examination of rich herbarium material and intensive field experiences. Their importance, variability and applicability is subsequently discussed. 2.1. Life cycle and life forms The Heliotropium species of the presented area are either annuals or perennials (hemicryptophytes and chaemphytes). Distinction of life forms is sometimes only possible with presence of root stock or existence of last year remainings in herbarium specimens. There are three species that may occur as well in an annual, a biennial or perennial form, H. biarmulatum, H. noeanum and H. remotißorum. The first one is growing in East Afghanistan and in the adjacent area of Pakistan. It is usually a perennial, but sometimes annual specimens were observed. H. dichcophorum was separated only based on that special variability of habit. H. noeanum is a common annual in Zagros foothills extending in Southwest of Iran, but it is becoming biennial to perennial in its more southern populations of southern Fars. H. remotiflorum is found in Southeast of Iran as far as Baluchestan part of Pakistan and South Afghanistan. Clearly annual and perennial forms exist next to each other without geographical separation. Such a variabihty in life forms is probably a result of favourable climate and a long life cycle. © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/;189 www.biologiezentrum.at Normally Heliotropium species have a long flowering period which is in most parts of Iran disrupted by the cold winter. In southern parts of Pars province as well as in Baluchestan due to its warmer climate there is no rigorous climatic disruption of growing and flowering season. Therefore some individuals of basically annuals may continue their life cycle under those opti- mal conditions for more than one season as biennial or even perennial forms. 2.2. Branching and habit Most species are erect, ascending with divaricately branches or sometimes branched fi^om the base. Due to variability of habits and branching modi there are no taxonomically important differences between species. Worthy to remark seems the always prostrate habit of//, supinum and H. curassavicum. H. mahfolium may be prostrate, ascending or erect. 2.3. Indument The quite common double indument of many species consists of short and long hairs. The dominant shorter ones are dense and mixed with scattered long hairs of about 1.5-2 times the length of the short ones. Hairs subtending by a tuberculate base varying in size and density. Usually there is a direct relation between tubercle size, thickness and length of hairs. With respect to general view of indument the species could be categorized as following: - villose indument is common in many species (e.g. H. europaeum s.l., H. bovei, H. noeanum, etc.), - densely tomentose species (e.g. H. biannulatum, H. brevilimbe, H. crassifolium and H. kaserunense), - perennial species with long scabrous hairs on large tubercles (e.g. //. bacciferum s.l. and psammophytic populations of//, dasycarpum subsp. transoxanum), and - glandulose hairs mixed with simple ones appear in the two related species H. agdense and H. suaveolens as well as H. biannulatum, H.fragillimum, H. macrolimbe and H. zeylanicum. - Multicellular hairs were found in two related species H. griffithii and //. buchahcum. - Furtheron H. buchahcum has pannose-floccose whitish hairs which are unique for Heliotropium in this area. - H. curassavicum is the only glabrous species. Usually there is a relationship between altitude of location and indument: at lower places with warmer climate plants have patent hairs, in contrast to that are appressed hairs at plants of