Tooth racks
| Tooth racks | ||||||||||||
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Yellow tooth rust ( Odontites luteus ) |
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| Odontites | ||||||||||||
| Ludw. |
The tooth rusts ( Odontites ) are a genus of plants within the family of summer root plants (Orobanchaceae). All tooth grates are semi-parasitic in that they grow into the roots of neighboring plant specimens with suction organs ( haustoria ) and receive water and nutrients from them via this connection. The main distribution area of the approximately 26 species is in the western Mediterranean , many species are endemic in a very limited area, only three species colonize a larger area.
description
Vegetative characteristics
Dental consolation species are mainly annual , herbaceous plants , a few species are short-lived perennial and woody . They can parasitize neighboring plants through root halls . Most representatives grow upright, only a few species such as Odontites corsicus , Odontites maroccanus and Odontites violaceus form shoots lying on the ground, on which only the inflorescences grow upright.
The constantly against the stem arranged distributed leaves are sessile. In the bud , the halves of the leaf blade are rolled up (revolut). The leaf blades are undivided. Since many species only partially unroll the leaves, the leaf margin is often bent downwards. About two thirds of the species have narrow-lanceolate to linear leaf blades that often look like heather due to the bent leaf edges . The remaining species have wider leaf blades that are lanceolate to oval-lanceolate. In most species, the leaf margin has entire margins or only one to three small teeth, only the species of the Odontites vernus group, as well as Odontites cebennensis and Odontites lanceolatus, have leaves with four to eight clearly defined teeth.
Tooth rust species are hairy with both simple and glandular trichomes . The simple trichomes are unicellular and more or less stiff-bristled; length, arrangement and density vary depending on the species. The glandular trichomes come in different forms. In addition to the taxonomically insignificant trichomes of the shield-shaped gland or short gland type that occur in all species, the various forms of the stalk gland trichomes (long-stalked head trichomes) are an important feature of the taxonomic classification of the genus. These can be absent, few-celled and broadly elliptical (lanceolatus type), multicellular and spherical-elliptical (pyrenaeus type) or multicellular and conical (viscosus type). The length of the stalk glands is usually between 150 and 700 μm, rarely they are only 50 μm long. The shield-shaped glands are built flat from a single-celled stalk, which is sunk into the epidermal tissue, and a flat arched shield made of narrow, parallel cells. The short glands are 20 to 90 µm long and their heads consist of one to four cells.
The root system consists of only a few, very large main roots, from which a weak network of finer roots emerges. The xylem of the roots is very well developed, in contrast to the phloem . Root hairs are usually only found on young seedlings and in the immediate vicinity of the haustoria.
The perennial species Odontites squarrosus , Odontites bocconii and Odontites linkii are usually only about four years old. The partially sterile side shoots that sprout annually at the base create a shrubby growth habit. The wood of these species has scattered to semi-ring pores in cross section, the pores being arranged in loose, radial rows. Due to the formation of multi-row layers of thick-walled latewood cells with only a few pores, annual rings can be discerned. The rays consist of radially short cells that are elongated in many rows and square in a few rows. The rays are usually surrounded by three to five rows of vaginal cells.
Inflorescences and flowers
In the many-flowered, strongly branched, racemose , inflorescences , the main axes of the tooth rust species do not end in a flower (polytelia). Depending on the species, the flowering zones of the inflorescences are short, compact and densely flowered or loose and stretched already at flowering time. Often the inflorescence elongates considerably during fruit ripening, so that it consists of elongated, rigid and slightly woody axes. The inflorescences are both at the main and at the side shoots, wherein the main inflorescence with a basal, up to 22 nodes extensive inhibition zone begins. In this inhibition zone are the so-called intercalary leaves (leaf-like bracts of strongly inhibited, non-blossoming flowers). The bracts become smaller towards the tip of the inflorescence and are always shorter than the leaves; the transition zone between foliage and bracts is different depending on the species. The flowers are usually in pairs in the nodes of the inflorescence. They bloom sequentially from bottom to top in most species, but the reverse order has been observed for some species.
The flowers are zygomorphic and very rich in shape within the genus: the organs often appear in variously modified forms. The length of the flowers varies between 6 and 12 millimeters. The calyx consists of four fused sepals that form two lips with a total of four whole-edged, broad to narrow triangular lobes. The calyx is often covered with stalk glands, which, like the entire calyx, often enlarge after the flowering period. The crown , which consists of five intergrown petals, is yellow or reddish-purple, with different shades and brightnesses of the two color groups. The crown consists of a more or less curved corolla tube and a two-lipped coronet. The upper lip, made up of two petal tips, forms a flat helmet. The spread out lower lip is three-lobed and the lateral corolla lobes are whole, the middle corolla lobe is outlined.
The four stamens come in two different forms, the two lower ones being longer than the two upper ones. They are either covered by the upper lip helmet or protrude more or less far beyond the crown. In all modes except the Odontites luteus group and Odontites corsicus the stamens tend together, so that the dust bag on the upper ends blunt entangled with each other by spirally twisted hair. The lower ends are pointed to a granny shape. The pollen grains are built uniformly in almost all species: in the equatorial cross-section they are almost triangular, the pollen grain wall (exine) is strongly thinned between the germinal crevices (mesocolpi). At the poles as well as at the edges of the Colpen the reticulum is wider meshed than on the Mesocolpen. Only Odontites hollianus , Odontites corsicus and Odontites rigidifolius deviate more or less strongly from this structure. The two-sheeted ovary contains four to forty ovules , the obliquely from the placenta hang down. The scar is head-shaped.
Fruits and seeds
The fruits of the tooth rust species are stiff-haired capsule fruits in the upper half or in the upper third . They open up in fissures by tearing the carpels along the midrib from top to bottom. The largest capsule fruits have Odontites hollianus with about 9.1 millimeters in length, the shortest Odontites viscosus and Odontites maroccanus with about 3.5 millimeters in length each. The fruits contain many seeds. The seeds are spindle-shaped, 1.2 to 2.8 millimeters long and ribbed. The wings of the seeds are cross-grooved.
ecology
development
The seeds germinate in the spring after an obligatory winter rest (cold induction). The germination takes place epigeal . The small cotyledons are up to 1.5 millimeters long; they are elliptical and have entire margins. In the leaf axils on the main shoot, side branches form in the course of development, which can branch out one more time. Like the main shoot, they also form racemose inflorescences. Most species of the genus shed their leaves before or at the latest during the flowering period, the bracts are usually shed later, so that the fruits stand on the completely leafless sprouts.
Parasitism
If a tooth rust root touches the root of another plant, it tries to establish a connection to this root via simple contact organs, the haustoria . Other parts of the plant, such as above-ground shoot axes or rhizomes, are rarely attacked. Upon successful entry of the haustoria into the host, a connection is established between the xylem of both plants. Through this connection, the tooth racks remove water from their hosts, as well as the organic compounds and inorganic nutrient ions dissolved therein. A prerequisite for the transport of nutrients in the direction of the tooth grid is a high level of water being released by the leaves. This is achieved through the glands, which occur in large numbers in almost all types of tooth rust, through guttation and, above all, through perspiration during the day. Only in species such as the yellow tooth rust ( Odontites luteus ), which grow in particularly sunny locations, are fewer glands present.
Within the summer root family, the parasitism of the tooth racks is regarded as a very simple form. The root systems are only slightly remodeled, the haustoria are pronounced as simply structured secondary hausoria (which do not yet arise at the beginning of the seedling development). Tooth racks are not host-specific, which means that they infect almost all plants in their vicinity. It often happens that they also attack plants of their own species. The host plants are obviously not affected by the infestation. Since the plants have their own chlorophyll , they can develop without a host ( autotrophic ) ( facultative parasitism ). However, vitality, degree of branching and also fertility are strongly dependent on the parasitized hosts; Plants that grow purely autotrophically are much weaker and often cannot develop seeds . Grasses in particular are suitable as host plants because their numerous fiber roots offer good attack opportunities for the haustoria.
pollination
Two types of pollination mechanisms can be distinguished within the genus. In the homogamous and necessarily autogamous (self-fertilizing) type, which occurs, for example, in Odontites powellii , Odontites corsicus and Odontites vulcanicus , self-fertilization already takes place in the bud ( Kleistogamy ). The anthers pop open before they even open up; the stylus, which is then bent back, lies in such a way that the scar is located exactly between the anthers and is thus dusted. In the open flower, the stylus usually does not protrude from the flower, but is hidden in the helmet.
The protogynous (pre-female) type usually promotes cross- pollination : the ready-to-receive stylus already protrudes from the not yet opened bud, while the stamens are still closed inside. These spring up two days later at the earliest, when the flower has already opened. There are various variants of this type of pollination, some of which enable subsequent self-pollination (weak protogyny), while others prevent it completely (strong protogyny). Depending on the order of the inflorescence, fertilization is promoted by pollen from the same inflorescence ( geitonogamy , if the inflorescence sequence is from bottom to top) or by pollen from other inflorescences or individuals ( xenogamy , if the inflorescence is from top to bottom).
Usually bees and bumblebees (Apiformes) are the pollinators of the protogynous flowers ( melittophilia ). The main pollinators differ depending on the size of the flowers: on the smaller flowers up to about 7 millimeters in length, mainly honeybees ( apis ) can be observed, while the larger flowers over 9 mm in length are almost exclusively visited by bumblebees ( bombus ). The tooth rust sawhorn bee specializes in the predominant visit of summer root plants ( oligolecty ), in addition to tooth rust , it occasionally collects nectar from eye rust ( Euphrasia ) and quail wheat ( melampyrum ).
Spread
The seeds of the tooth grates are not adapted to a particular form of expansion and are therefore usually only spread in the immediate vicinity of the plant. Although they are very small, the weight of the seeds is too high for wind propagation ( anemochory ). Spread by animals ( epizoochory ) is also very unlikely, since the seeds are not winged, such as those of the Bartsia , and so do not stick to smooth and moist surfaces. Limited distribution by being dragged along in hay is only possible for a few species ; These include above all the various clans of the Odontites vernus group.
Predators
The caterpillars of the Spannerart Perizoma bifaciata feed oligophagous (only accepting a few food plants) among other things on the immature seeds of the yellow tooth rust ( Odentites luteus ) and the spring tooth rust ( Odontites vernus ). In addition, the caterpillars of the gamma owl ( Autographa gamma ) from the owl butterfly family (Noctuidae) were found on the spring tooth rust ( Odontites vernus ).
Distribution and locations
Most of the species in the genus are native to the western Mediterranean . Two priority areas, each with six species, are located in northwest Africa , one in the central Atlas Mountains in Morocco , and another in eastern Algeria and Tunisia . Another focus with a total of five species is in north-east Spain , four of the species occurring there are endemic . This local demism is widespread within the genus, many species are only known from small populations in mountains or on islands, around a third only occur in residual populations and are threatened with extinction. Only three species have a larger distribution area: Odontites viscosus, with its main distribution center on the southern slope of the Pyrenees, extends in the north to the western and central Alps ; the yellow tooth rust ( Odontites luteus ) also inhabits the driest areas of summer in Central Europe and extends from northeastern Spain to the Volga plateau and scattered to the Caucasus , the Crimea and the eastern Taurus Mountains ; the spring tooth rust ( Odontites vernus ) extends north to southern Scandinavia and over large parts of the temperate areas of Eurasia to East Asia .
The locations are at altitudes between 0 and 2500 meters. Most species are adapted to dry, often rocky and stony bristles and steppe lawns or light stone oak , downy oak and pine forests . In contrast, the spring tooth rust ( Odontites vernus ) occurs mainly in fresh to wet and nutrient-rich lawn communities and can even colonize the salt marshes of the East and North Sea coasts. Almost all species have a very high light requirement, only a few, for example Odontites viscosus , Odontites cebennensis and Odontites powellii , also grow in partially shaded locations.
Systematics
External system
The genus Odontites belongs to the tribe Rhinantheae within the family of Orobanchaceae . The relationships within the tribe Rhinantheae have not yet been clearly clarified and are discussed controversially.
The first molecular biological study that included a tooth rust species was published by Jonathan Bennett and Sarah Mathews in 2006. The following cladogram shows the suspected relationships based on this investigation (simplified to). Representatives of the genera Bartsia and the common root ( Lathraea ) could not be clearly classified, and the genera Bartsia and Parentucellia could not be clearly distinguished either. The genera Macrosyringion , Odontitella , Bornmuellerantha and Bartsiella , which are occasionally classified as Odontites , and the genera Hedbergia and Nothobartsia , which are probably also closely related , were identified by Bennet et al. 2006 not yet included in molecular genetic studies.
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Scheunert et al. Were able to clarify the family relationships somewhat better. 2012, but many questions remained open.
Internal system
According to the monograph by Markus Bolliger (1996), the genus Odontites comprises the following 26 species. Some phenetically very similar species were combined into species groups in this work; other taxa previously described as species were only recognized with the status of a subspecies.
Habit, opposite leaves and flowers of Odontites hollianus
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Taxonomy, Botanical History and Etymology
The genus name Odontites goes back to Pliny the Elder . He names a plant species that probably belongs to this genus with the name odontītis , which is probably derived from the Greek word όδούς ( odous for tooth; plural: Odontes). In part, it is assumed that this name is due to the alleged effectiveness of this plant species against toothache . It is more likely, however, that the name refers to the tooth-shaped jagged edges of the sepals. On the other hand, it is also conceivable that the analogy between the teeth of the leaves and the teeth of humans led to the plant being assigned a corresponding effectiveness. The use of the bitter-tasting extract known as Herba Euphrasiae rubra was described as "long out of use" as early as the early 19th century. This plant species is also said to have been used to relieve menstrual cramps ; for this purpose, crushed plants were placed in the shoes.
The genus Odontites was established in 1757 by Christian Gottlieb Ludwig . Type species is Odontites vulgaris Moench . Although Carl von Linné published some of the types that today belong to the tooth rusts, he assigned them to the eye rusts ( Euphrasia ). As a result, the species were repeatedly listed either as an independent genus, in some cases individual groups of species were separated out as their own genera, or the species were optionally assigned to the eyebright or the Bartsia . The reason for this is the morphological independence of many tooth rust species, which suggests a placement between the two large genera Euphrasia and Bartsia . Various concepts were also presented for the breakdown within the genre, none of which are generally accepted.
Synonyms for Odontites Ludw. are: Odontites sect. Orthantha Benth. , Dispermotheca Beauverd , Macrosyringion Rothm. , Odontitella Rothm. , Orthantha (Benth.) A. Kern. , Orthanthella Rauschert .
A first subdivision of the genus into the sections Lasiopera , Orthantha and Euodontites comes from George Bentham from the year 1846. Later, however, he deviated from this concept himself and in 1876 assigned the species to the genus Bartsia , whereby he only the sections Orthantha and Euodontites used. In 1888 Anton Kerner von Marilaun separated the species around Odontites luteus into the genus Orthantha . This concept was also adopted by Richard Wettstein in 1891 and later by his student Josef Hoffmann . From 1897 Hoffmann published a multi-part monograph on the European species of the genus known to him under the title “Contribution to the knowledge of the genus Odontites ”. Its subdivision within the genus into five unnamed groups is mainly due to the characteristics of the flowers. The species group around Odontites viscosus was separated out in 1911 by Gustave Beauverd as the genus Dispermotheca , he recognizes the Orthantha with the status of a subgenus of Odontites . He also suggests placing the species Odontites aucheri in its own genus or section, but does not undertake this rearrangement himself. The most recent classification of the species within the genus was made by Werner Rothmaler in 1943, who divided the tooth grates into the sections Euodontites , Orthantha and Dispermotheca . At the same time he implements Beauverd's proposal and divides Odontites aucheri into the genus Bornmuellerantha that he has newly established . In addition, he established the genera Macrosyringion and Odontitella and thus separated two further species from Odontites . Not until 1996 was another monographic treatment of the genre by Markus Bolliger . He does not divide the genus into sections, but recognizes the genres established by Rothmaler and divides Odontites rameauanus into a further independent and monotypical genus Bartsiella .
Regardless of which species concept has been used, the types of today's genre were Odontites traditionally the family of Figworts attributed (Scrophulariaceae). In 1907 Raffaello Bellini established a subdivision of the family in which he separated all parasitic from non-parasitic genera. The parasitic genera, including Odontites , he assigned to the subfamily Rhinanthoideae. The natural composition of this subfamily was subsequently confirmed primarily by morphological and later also by molecular biological studies. Since the early 1990s, however, it has become more and more apparent that the classic family concept of figwort plants does not represent natural relationships. As a result, Nelson D. Young et al. proposed that the genera of the previous subfamily Rhinathoideae be assigned to the family of summer root plants (Orobanchaceae). This classification was made in 2001 by Richard Olmstead et al. carried out and in 2003 also included in the systematics of the Bedecktsamer according to APG II .
swell
Individual evidence
Most of the information in this article has been taken from the sources given under literature; the following sources are also cited:
- ↑ a b data sheet in Flora Vascular .
- ↑ a b c d e Zhi-Yun Zhang, Nikolai N. Tzvelev: Odontites Ludwig , p. 96 - online with the same text as the printed work , In: ZY Wu, PH Raven (ed.): Flora of China , Volume 18: Scrophulariaceae through Gesneriaceae. Science Press, Beijing and Missouri Botanical Garden Press, St. Louis, 1998, ISBN 0-915279-55-X .
- ↑ a b R. N. Govier et al .: Hemiparasitic Nutrition in Angiosperms. II: Root Haustoria and Leaf Glands of Odontites verna (Bell.) Dum. and their relevance to the abstraction of solutes from the host. In: New Phytologist , Volume 67, 1968. pp. 963-972.
- ↑ Hans Christian Weber: About host plants and parasitism of some Central European Rhinanthoideae (Scrophulariaceae). In: Plant Systematics and Evolution , Volume 125, 1976, pp. 97-107. doi : 10.1007 / BF00986775
- ↑ Hans Christian Weber: On the evolution of parasitism in the Scrophulariaceae and Orobanchaceae. In: Plant Systematics and Evolution , Volume 136, 1980, pp. 217-232. doi : 10.1007 / BF01004627
- ↑ Denis Michez, Connal Eardley: Monographic revision of the bee genus Melitta Kirby 1802 (Hymenoptera: Apoidea: Melittidae). In: Ann. soc. entomol. Fr. (ns) , Volume 43, Issue 4, 2007. pp. 379-440. PDF; 6.6 MB
- ↑ Axel Hausmann: Sterrhinae. In A. Hausmann (Ed.): The Geometrid Moths of Europe 2. Apollo Books, Stenstrup 2004, ISBN 87-88757-37-4 .
- ↑ Compare HOSTS - a Database of the World's Lepidopteran Hostplants , query of September 27, 2008.
- ^ A b c Jonathan R. Bennet, Sarah Mathews: Phylogeny of the parasitic plant family Orobanchaceae inferred from Phytochrome A. , In: American Journal of Botany , Volume 93, Number 7, 2006. pp. 1039-1051. Abstract.
- ↑ Agnes Scheunert, Andreas Fleischmann, Catalina Olano-Marín, Christian Bräuchler, Günther Heubl: Phylogeny of tribe Rhinantheae (Orobanchaceae) with a focus on biogeography, cytology and re-examination of generic concepts. In: Taxon , Volume 61, Issue 6, 2012, pp. 1269-1285. JSTOR 24389112
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj Karol Marhold, 2011: Scrophulariaceae : Datasheet Odontites In: Euro + Med Plantbase - the information resource for Euro-Mediterranean plant diversity.
- ↑ a b Ridha El Mokni, Houcine Sebei, Mohamed Hédi El Aoun: Rediscovery of a rare North African endemic Odontites (Orobanchaceae): first record and variability from Tunisia. , In: International Journal of Advanced Research , Volume 3, Issue 2, 2015, pp. 376–382. Full text PDF.
- ^ A b Salvatore Brullo, Valeria Tomaselli, Robert Philipp Wagensommer: A new species of Odontites (Orobanchaceae) from southern Italy , In: Phytotaxa , Volume 213, Issue, 3, June 17, 2015, pp. 271–281. doi : 10.11646 / phytotaxa.213.3.7
- ↑ Odontites in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved August 4, 2015.
- ↑ Helmut Genaust: Etymological dictionary of botanical plant names. 3rd, completely revised and expanded edition. Birkhäuser, Basel / Boston / Berlin 1996, ISBN 3-7643-2390-6 (reprint ISBN 3-937872-16-7 ).
- ^ Martin Krampen: plant reading book: plant study - plant use - plant poetry. Georg Olms Verlag, 1994, ISBN 978-3-487-09829-6 .
- ^ Carl Ferdinand Graefe: Encyclopaedic Dictionary of Medicinal Sciences . tape 11 . Verlag von Veit et Comp., 1834 ( limited preview in Google book search).
- ↑ August Johann Georg Carl Batsch: Attempt at a guide to the knowledge and history of plants designed for academic lectures and provided with the necessary illustrations . Part 2. Johann Jacob Gebauer, 1788 ( limited preview in the Google book search).
- ^ Heinrich Gottfried Mattuschka: Flora Silesiaca or Directory of Plants Growing Wild in Silesia , Part 2, Verlag Wilhelm Gottlieb Korn, Breslau and Leipzig, 1777.
- ^ Christian Gottlieb Ludwig: Institutiones Historico-Physicae Regni Vegetabilis , Verlag JF Gleditsch, Leipzig, 1757.
- ↑ Linnaeus described Euphrasia odontites (= Odontites vulgaris ), Euphrasia linifolia , Euphrasia lutea (both = Odontites luteus ) and Euphrasia viscosa (= Odontites viscosus ); compare: Carl von Linné: Species Plantarum , Lars Salvius Verlag, Stockholm, 1753. Page 604f.
- ↑ George Bentham: Odontites. In: Alphonse de Candolle (ed.): Prodromus systematis naturalis regni vegetabilis , Volume 10, 1846. pp. 549-552. scanned at botanicus.org .
- ↑ George Bentham: Genera plantarum: ad exemplaria imprimis in Herberiis Kewensibus servata definita , Volume 2, Part 2, Reeve & Co., Williams & Norgate , London 1876. Scanned at botanicus.org .
- ↑ Josef Hoffmann: Contribution to the knowledge of the genus Odontites. In: Österreichische Botanische Zeitschrift , Volume 47, Number 4, April 1897. Pages 113–117. doi : 10.1007 / BF01795149
- ^ Werner Rothmaler: The splitting of Odontites Hall. ex. Tin. In: Communications of the Thuringian Botanical Association , New Series, Issue 50: Festschrift for the 80th birthday of Joseph Bornmüller . Verlag Gebr. Knabe KG, Weimar, 1943. Pages 224-230.
- ↑ Nelson D. Young et al .: The evolution of parasitism in the Scrophulariaceae / Orobanchaceae: plastid gene sequences refute an evolutionary transition series. In: Annals of the Missouri Botanical Garden , Volume 86, 1999, pp. 876-893. scanned at botanicus.org .
- ^ Richard Olmstead et al .: Disintegration of the Scrophulariaceae. In: American Journal of Botany , Volume 88, Issue 2, 2001. pp. 348-361.
- ^ Angiosperm Phylogeny Group: An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. In: Botanical Journal of the Linnean Society , Volume 141. pp. 399-436. doi : 10.1046 / j.1095-8339.2003.t01-1-00158.x
literature
- Markus Bolliger: Monograph of the genus Odontites (Scrophulariaceae) and the related genera Macrosyringion, Odontitella, Bornmuellerantha and Bartsiella. In: Willdenowia: Annals of the Botanic Garden and Botanical Museum Berlin-Dahlem , Volume 26, 1996. pp. 37-168. (Online: Part 1 (PDF; 2.4 MB), Part 2 (PDF; 1.2 MB), Part 3 (PDF; 1.2 MB), Part 4 ; PDF; 2.1 MB)
- Agnes Scheunert, Andreas Fleischmann, Catalina Olano-Marín, Christian Bräuchler, Günther Heubl: Phylogeny of tribe Rhinantheae (Orobanchaceae) with a focus on biogeography, cytology and re-examination of generic concepts. In: Taxon , Volume 61, Issue 6, 2012, pp. 1269-1285. JSTOR 24389112
- Daniel M. Joel, Jonathan Gressel, Lytton J. Musselman: Parasitic Orobanchaceae: Parasitic Mechanisms and Control Strategies . Springer Science & Business Media, 2013, ISBN 978-3-642-38146-1 , p. 513 ( limited preview in Google Book search).
Web links
- Look for "Odontites" on the IUCN Red List of Endangered Species .
Map with all linked sites: 