Orobanche Clausonis Pomel (Orobanchaceae) in the Iberian Península
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OROBANCHE CLAUSONIS POMEL (OROBANCHACEAE) IN THE IBERIAN PENÍNSULA by MICHAEL JAMES YATES FOLEY* Resumen FOLEY, MJ.Y. (1996). Orobanche clausonis Pomel (Orobanchaceae) en la Península Ibérica. Anales Jard. Bot. Madrid 54:319-326 (en inglés). Orobanche clausonis Pomel fue descrita sobre plantas recolectadas en Argelia, donde parasi- taba a Asperula hirsuta (Rubiaceae). Desde entonces, ha sido colectada ocasionalmente en va- rias localidades del sudoeste de Europa, especialmente en la Península Ibérica. Sin embargo, es aún mal conocida. En este trabajo se estudian la morfología y la taxonomía de la especie y se propone que las plantas europeas queden cobijadas bajo el trinomen O. clausonis subsp. hes- perina (J.A. Guim.) MJ.Y. Foley, comb. & stat. nov. Palabras clave: Spermatophyta, Orobanchaceae, Orobanche, taxonomía, Península Iberica, Argelia. Abstract FOLEY, MJ.Y. (1996). Orobanche clausonis Pomel (Orobanchaceae) in the Iberian Península. Anales Jard. Bot. Madrid 54:319-326. Orobanche clausonis Pomel was first described frorn Algeria where it was thought to be para- sitic upon Asperula hirsuta (Rubiaceae). Since then, germine records have been scarce and al- though occasionally collected from various localities in south-westera Europe (especially the Iberian península), where it is mainly parasitic upon members of the Rubiaceae, its identity and taxonomy have been poorly understood. Based principally on the limited number of preserved specimens available, the general morphology and taxonomy of O. clausonis has been investi- gated. As a result, it is proposed that the European plants be separated as Orobanche clausonis subsp. hesperina (J.A. Guim.) MJ.Y. Foley, comb. & stat. nov. Key words: Spermatophyta, Orobanchaceae, Orobanche, taxonomy, Iberian Península, Algeria. INTRODUCTION AND HISTORY of this results from the scarcity of subsequent records and the dearth of specimens retained Since first described by POMEL (1874:107) in herbaría. In the present work an attempt has based upon material collected in 1858 by been made to reassess the taxonomic status of Clauson and growing on Asperula hirsuta at the plant based mainly upon the relatively Mouzaia, Algeria, there has been much con- limited quantity of preserved material avail- fusion regarding the identity and taxonomic able. Only one present-day locality has so far status of Orobanche clausonis, a holoparasite been definitely identified for the plant, but mainly on members of the Rubiaceae. Much such apparent scarcity may be a result of mis- * Institute of Environmental and Biological Sciences, División of Biological Sciences, University of Lancaster. Lancaster, LA14YQ (United Kingdom). 320 ANALES JARDÍN BOTÁNICO DE MADRID, 54.1996 identification and under-recording rather than O. clausonis, although it was included in the a reflection of extreme rarity, although it is subsequent supplement (WILKOMM, 1893: undoubtedly uncommon. 188) based on BECK'S (1890:235) verification In his original description of O. clausonis, of the Granada specimen. Later, when Gui- POMEL (1874: 107) remarked on several im- maraes published his monograph on Portu- portant characters: the rather dense inflores- guese Orobanche he included under O. luco- cence, the tubular to campanulate corollas, rum A. Braun (GUIMARAES, 1904: 85) a new the calyx divided into four shortly lanceolate, variety hesperina based on plants from four subequal divisions, and the insertion of the fil- collections by Welwitsch and by Daveau. aments in the lowest quarter of the corolla These were parasitic upon Rubia spp. and in tube, the filaments themselves being slightly one case upon Quercus pseudococcifera and pubescent at their base. Of these characters, it were collected from a rather limited área of is the shape of the broad, relatively short, div- central Portugal. From elsewhere in his mono- ided calyx as evidenced in the type specimen graph it is clear that Guimaraes was aware of (Mouzaía, 1858; Clauson, MPU), which es- the principal characters of Pomel's O. clauso- pecially separates O. clausonis from similar nis since he occasionally quotes such charact- taxa. ers in comparison to other taxa and he placed it Following Pomel's diagnosis, there appe- cióse to O. mauretanica Beck (grex Minores). ars to be no mention of O. clausonis until a However he did not consider O. clausonis to be a Portuguese plant ñor did he refer to it in dismissive comment by BATTANDDER & TRA- BUT (1890: 661) that it was merely a glabres- relation to his O. lucorum var. hesperina. His cent form of O. galii Vaucher var. atlantica attribution of the Welwitsch and Daveau spe- having more hispid filaments and hairy ant- cimens to O. lucorum is intriguing and a pos- hers. This latter taxon, apparently parasitic sible explanation may lie in a combination of upon Galium tunetanum, is a small-flowered factors. True O. lucorum, parasitic on Berberis variant of the widespread European O. caryo- spp., has a narrow distribution in central Eur- phyllacea Sm., a very different and distinctive ope, occurring essentially over a limited área plant to O. clausonis, again apparently restric- of the eastern Alps. It is readily separated from ted in its host to members of the Rubiaceae. It Guimaraes' Portuguese var. hesperina on is not clear whether Battandier & Trabut's calyx shape alone - the lobes of O. lucorum comments were based upon actual experience being much longer and narrower that in var. of O. clausonis, but any affinities between hesperina. On the relatively limited informa- it and variants of O. caryophyllacea can be tion available at the time, it is possible that dismissed upon morphological grounds. In Guimaraes associated his var. hesperina with O. lucorum based on similar colouration (yel- the same year, BECK (1890: 234) included O. clausonis in his monograph of the genus low). Also, a variant or segregate of O. luco- Orobanche, listing Clauson's Algerian loca- rum from south-eastern France parasitic upon lity, although not having seen the original spe- Rubus spp. had been described as O. rubi cimen. He also added a record of Boissier's (DUBY, 1828:350). This, together with the fact and Reuter's from Granada, Spain, in 1849 that Welwitsch had annotated one of his sheets (specimen now in LE - corolla dissections in "O. rubii", may have led to a possible misin- PRC!) which at that time appeared to be the terpretation of their respective hosts and there- first and only European record for the plant. fore to the connection with O. lucorum. Ne- He surprisingly placed O. clausonis cióse to vertheless, Guimaraes did indícate that the taxa of the O. minor group (i.e. in his grex Mi- specimens of Portuguese "O. rubi Duby" nores) despite its very different calyx shape, which he had seen differed from typical O. lu- which contrasts with the elongated, tapering corum in several respects and for that reason calyces of members of his grex Minores. he gave them the varietal rank hesperina. In Prodromus Florae Hispanicae, WlL- In Flore de Portugal, COUTINHO (1913: KOMM & LANGE (1870) made no reference to 569) took a different view and accepted M.J.Y. FOLEY: OROBANCHE CLAUSONIS 321 O. clausonis as a Portuguese plant. This was been contacted for the loan of material. From presumably based upon the same specimens the response it is evident that collections are considered by Guimaraes under his O. luco- very scarce and this possibly reflects the plant' s rum var. hesperina, since he usted the locali- overall rarity in nature. Loan specimens and ties and hosts of Welwitsch's collections, an- specimen photographs have been obtained notated some of the sheets and added a taxo- from the following herbaria: E, COI, FI (pho- nomic description. He did not include O. lu- to), G, LISE, LISU, LTR, MPU, PRC, RNG. corum for Portugal. This stance has been A range of quantitative morphological maintained subsequently for Portugal (COU- characters which are considered to be of taxo- TINHO, 1939:673; SAMPAIO, 1946:498; FRAN- nomic significance within the genus were CO, 1984:280) but O. clausonis is excluded in examined on these specimens and where ap- works covering Algeria and Morocco (SAU- propriate single detached corollas were sof- VAGE, 1961; NÉGRE, 1962; QUEZEL & SANTA, tened prior to dissection by soaking for five 1963) and most regions of Spain (COSTA, minutes in boiling water containing a small 1864; FERNÁNDEZ-GALIANO & HEYWOOD, amount of surfactant. Measurements in- 1960; VALDÉS & al., 1987; ROMO, 1989; cluded: plant height, inflorescence length, in- BOLOS & al., 1990; SANZ, 1990, 1992). Ho- florescence height, corolla length, corolla wever, in eastern Andalucía there is a single width, overall calyx length, calyx length to record by SAGREDO (1987: 421) of plants the división of the teeth, and typical height of parasitic upon Galium verrucosum at Barran- filament insertion above the corolla base. co del Caballar, Almería and another by MU- Estimates have also been made of inflores- ÑOZ-MEDINA (1944:121) from near Lanjarón, cence density, corolla shape, calyx shape and Granada province. Two collections from Gal- of filament pubescence. The results are shown do, north-west Spain, and mentioned by ME- in Table 1. It should be borne in mind that di- RINO (1906: 45) under O. lucorum, may also mensions of width are likely exceed to those be O. clausonis. FRANCO (1984: 280) recently found in living material. extended the Portuguese range of O. clauso- nis to include the Atlantic off-shore Ilhas Ber- lengas. RESULTS AND DISCUSSION In Flora Europaea, CHATER & WEBB From the results shown in Table 1 it is clear (1972: 292) listed it as present in Spain, Por- that the specimens possess many of the main tugal and Malta, based upon information gi- characters indicated by POMEL (1874: 107- ven in BECK'S monographs (1890: 235; 1930: 108) in his original diagnosis of O. clausonis, 218). However, the solé Maltese record ap- viz: corollas tubular to campanulate, calyces pears to be that of Sommier's collection (FI) divided into four, short, subequal divisions, which Beck named f.