Category Archives: Botany

Friday Fellow: Flat-Leaved Scalewort

by Piter Kehoma Boll

Time and again, if we want to understand all the nuances of life on Earth, we have to look to the small things that live close to the ground or on the bark of the trees. And one of this small creatures is the flat-leaved scalewort, Radula complanata.

Growing on rocks or trees, the flat-leaved scalewort is quite common in the northern hemisphere, especially in North America and Eurasia, and belongs to the diverse but hidden group of the liverworts.

36401_orig

Radula complanata growing on the trunk of an ash tree (Fraxinus excelsior) in England. Credits to BioImages – the Virtual Fieldguide (UK).*

In Europe, the flat-leaved scalewort occurs in dense forests, where it finds shelter to the direct exposure to the sun. In this forests, it shows a clear preference for growing on broad-leaved trees and shrubs, such as the goat willow Salix caprea and its hybrids. It usually grows friendly with other epiphytic liverworts on the same tree, although not much clustered.

Although usually harmless, the flat-leaved scalewort can cause skin irritation (more precisely, allergenic contact dermatitis) when handled, which seems to be related to the presence of certain alcaloids, such as bibenzyls, in its tissues.

– – –

References:

Asakawa, Y.; Kusube, E.; Takemoto, T.; Suire, C. (1978) New Bibenzyls from Radula complanataPhytochemistry, 17: 2115–2117. https://dx.doi.org/10.1016/S0031-9422(00)89292-4

Heylen, O.; Hermy, M. (2008) Age structure and Ecological Characteristics of Some Epiphytic Liverworts (Frullania Dilatata, Metzgeria Furcata and Radula Complanata). The Bryologist, 111(1): 84-97. https://doi.org/10.1639/0007-2745(2008)111[84:ASAECO]2.0.CO;2

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License.

Advertisements

Leave a comment

Filed under Botany, Friday Fellow

The history of Systematics: Plants in Systema Naturae, 1758 (Part 6)

by Piter Kehoma Boll

Finally a new post in the History of Systematic series. This is the sixth part of Linnaeus’ classification of plants. See parts 1, 2, 3, 4 and 5. Here, I’ll present two more classes which are characterized by having the stamens arising from a common base in the flower.

16. Monadelphia (“single brothers”)

“Husbands, or brothers, arising from one base”, i.e., the filaments of the stamens are fused in a single body.

16.1 Monadelphia Pentandria (“single brothers, five males”), five stamens fused into a single structure: Waltheria (gray mallows), Hermannia (hermannias), Bombax (cotton trees), Melochia (melochias).

1758Linnaeus_monadelphia_pentandria

These 5 species belonged Linnaeus’ Monadelphia Pentandria (from left to right): sleepy morning (Waltheria indica), three-leaved hermannia (Hermannia trifoliata), chocolateweed (Melochia corchorifolia), red cotton tree (Bombax aculeatum, now Bombax ceiba). Credits to J. M. Garg (sleepy morning), C. E. Timothy Paine (hermannia), Jeevan Jose (chocolatewed), Dinesh Valke (cotton tree).

16.2 Monadelphia Decandria (“single brothers, ten males”), ten stamens fused into a single structure: Connarus (Indian zebrawood), Geranium (geraniums), Hugonia (a species of doubtful identity).

1758Linnaeus_monadelphia_decandria

The above species were put by Linnaeus in the order Monadelphia Decandria: Indian zebrawood (Connarus monocarpus, left) and bigroot geranium (Geranium macrorhizum, right). Credits to Dinesh Valke (zebrawood) and Wikipedia user Hardyplants (geranium).

16.3 Monadelphia Polyandria (“single brothers, many males”), many stamens fused into a single structure: Stewartia (silky camellia), Napaea (glade mallow), Sida (fanpetals), Adansonia (baobabs), Pentapetes (gojikas), Gossypium (cottons), Lavatera (tree mallows), Malva (mallows), Malope (mallow worts), Urena (caesarweeds), Alcea (hollyhocks), Hibiscus (hibiscuses), Althaea (marshmallows), Camellia (camélia).

1758Linnaeus_monadelphia_polyandria

Linnaeus classified the above species as Monadelphia Polyandria (from left to right, top to bottom): common baobab (Adansonia digitata), arrowleaf fanpetal (Sida rhombifolia), glade mallow (Napaea dioica), common marshmallow (Althaea officinalis), common hollyhock (Alcea rosea), common mallow (Malva sylvestris), garden tree mallow (Lavatera thuringiaca), common caesarweed (Urena lobata), Levant cotton (Gossypium herbaceum), Chinese hibiscus (Hibiscus rosa-sinensis), gojika (Pentapetes phoenicea), silky camellia (Stewartia malacodendron), common camellia (Camellia japonica). Credits to Jeevan Jose (fanpetal), Pablo Alberto Salguero Quiles (marshmallow), Stan Shebs (hollyhock), Joanna Voulgaraki (mallow), Bob Peterson (caesarweed), H. Zell (cotton), Andrew Fogg (hibiscus), Frank Vicentz (camellia), Wikimedia users Atamari (baobab), Botaurus stellaris (tree mallow), Melburnian (silky camellia), flickr users peganum (glade mallow), Lalithamba (gojika).

17. Diadelphia (“two brothers”)

“Husbands originating from a double base, as well as a double mother”, i.e., the filaments of the stamens are gathered in two bodies.

17.1 Diadelphia Pentandria (“two brothers, five males”), two structures formed of five fused stamens: Monnieria (monnieria).

17.2 Diadelphia Hexandria (“two brothers, six males”), two structures formed of six fused stamens: Fumaria (fumitories).

17.3 Diadelphia Octandria (“two brothers, eight males”), two structures formed of eight fused stamens: Polygala (milkworts), Securidaca (safeworts).

1758Linnaeus_diadelphia_hexandria_octandria

The plant to the left, the common fumitory (Fumaria officinalis) was in the order Diadelphia Hexandria, while the plant to the right, the common milkwort (Polygala vulgaris), was in the order Diadelphia Octandria. Credits to Isidre Blanc (fumitory) e Radio Tonreg (milkwort).

17.4 Diadelphia Decandria (“two brothers, ten males”), two structures formed of ten fused stamens: Amorpha (false indigo), Ebenus (ebonies), Erythrina (coral trees), Spartium (brooms), Genista (more brooms), Lupinus (lupins), Anthyllis (kidney vetches), Aeschynomene (jointvetches), Piscidia (), Borbonia (cape gorses), Aspalathus (more cape gorses), Ononis (restharrows), Crotalaria (rattlepods), Colutea (bladder sennas), Phaseolus (beans), Dolichos (longbeans, lablab bean), Orobus (vetchlings), Pisum (peas), Lathyrus (more vetchlings), Vicia (vetches), Astragalus (milkvetches), Biserrula (more milkvetches), Phaca (even more milkvetches), Psoralea (some trefoils), Trifolium (clovers or trefoils), Glycyrrhiza (licorices), Hedysarum (sweetvetches), Coronilla (more vetches), Ornithopus (bird’s-foot), Scorpiurus (scorpion’s-tails), Hippocrepis (horseshoe vetches), Medicago (alfalfas), Trigonella (fenugreek and allies), Glycine (soybeans), Clitoria (pigeonwings), Robinia (locusts, caraganes, riverhemps), Indigofera (indigos), Ulex (gorses), Cicer (chickpea), Ervum (lentils, vetches), Cytisus (laburnums and even more brooms), Galega (galegas), Lotus (bird’s-foot-trefoils), Arachis (peanut).

1758Linnaeus_diadelphia_decandria

These 36 plants were included in the order Diadelphia Decandria (from left to right, top to bottom): coral bean (Erythrina herbacea), fishfuddle (Piscidia erythrina, now Piscidia piscipula), heart-shaped capegorse (Borbonia cordata, now Aspalathus cordata), weaver’s broom (Spartium junceum), dyer’s broom (Genista tinctoria), desert false-indigo (Amorpha fruticosa), Indian jointvetch (Aeschynomeme indica), blue rattlepod (Crotalaria verrucosa), field restharrow (Ononis arvensis), common kidney vetch (Anthyllis vulneraria), white lupin (Lupinus albus), bladder senna (Colutea arborescens), common bean (Phaseolus vulgaris), lablab bean (Dolichos lablab, now Lablab purpureus), common pea (Pisum sativum), hairy vetchling (Orobus hirsutus, now Lathyrus hirsutus), grass vetchling (Lathyrus nissolia), common vetch (Vicia sativa), Chickpea (Cicer arietinum), lentil (Ervum lens, now Lens culinaris), common laburnum (Cytisus laburnum, now Laburnum anagyroides), common gorse (Ulex europaeus), peanut (Arachis hypogaea), licorice (Glycyrrhiza glabra), scorpion vetch (Coronilla glauca), little white bird’s-foot (Ornithopus perpusillus), horseshoe vetch (Hippocrepis comosa), prickly scorpion’s-tail (Scorpiurus muricatus), alpine sweetvetch (Hedysarum alpinum), indigo (Indigofera tinctoria), common galega (Galega officinalis), Asian pigeonwing (Clitoria ternatea), common soybean (Glycine max), alpine milkvetch (Astragalus alpinus), white clover (Trifolium repens), Cretan ebony (Ebenus cretica). Credits to Everglades NPS (coral bean), Jon Richfield (capegorse), Bernd Haynold (dyer’s broom), Dinesh Valke (jointvetch), J. M. Garg (rattlepod), Kristian Peters (restharrow, vetch, bird’s-foot), Massimiliano Marcelli (lupin), Mauricio Laurente (bean), Bogdan Giuşcă (hairy vetchling), Carl Davies-CSIRO (chickpea), Christian Kooyman (lentil), Jean François Gaffard (laburnum), H. Zell (peanut), Carsten Niehaus (scorpion vetch), Isidre Blanc (horseshoe vetch), Hans Hillewaert (scorpion’s-tail, clover), Nicola Cocchia (galega), Tusli Bhagat (pigeonwing), Jörg Hempel (milkvetch), Rüdiger Kratz (ebony), flickr users jayeshpatil912 (fishfuddle) and Eskimo Potato (sweetvetch), Wikimedia users Hectonichus (weaver’s broom), AnRo0002 (false indigo, kidney vetch, bladder senna), Dalgial (lablab), Rasbak (pea), Sannse (grass vetchling), Rosser1954 (gorse), Pharaoh han (liquorice), Pancrat (indigo), vegetalist (soybean).

18. Polyadelphia (“many brothers”)

Husbands originating from more than two mothers, i.e., stamens are gathered in three or many bodies.

18.1 Polyadelphia Pentandria (“many brothers, five males”), more than two structures of five fused stamens: Theobroma (cacao and bay cedar).

18.2 Polyadelphia Icosandria (“many brothers, twenty males”), more than two structures of twenty fused stamens: Citrus (citrus fruits trees).

18.3 Polyadelphia Polyandria (“many brothers, many males”), more than two structures of many fused stamens: Hypericum (St. Johnswort), Ascyrum (St. Andrew’s cross).

1758Linnaeus_polyadelphia

The cacao tree (Theobroma cacao, left) was one of the members of the order Polyadelphia Pentandria; the citron (Citrus medica, middle left) was a member of the order Polyadelphia Icosandria; and the Balearic St. Johnswort (Hypericum balearicum, middle right) and the St. Andrew’s cross (Ascyrum hypericoides, now Hypericum hypericoides) were members of the order Polyadelphia Polyandria. Credits to H. Zell (cacao tree), Christer T Johansson (citron), Wikimedia user Eric in SF (St. Johnswort), Bob Peterson (St. Andrew’s cross).

With a few exceptions, most of the plants in these classes currently belong to the families Malvaceae and Fabaceae (Leguminosae) of flowering plants. I guess we still need three more posts on the plants and then we are done! I hope the next part won’t take so long.

– – –

References:

Linnaeus, C. (1758) Systema Naturae per Regna Tria Naturae…

– – –

*Creative Commons License
All images are licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

5 Comments

Filed under Botany, Systematics, taxonomy

They only care if you are cute: how charisma harms biodiversity

by Piter Kehoma Boll

Which of the two species shown below is more charismatic?

Tangara_chilensis

Tangara chilensis (Paradise Tanager). Photo by flickr user ucumari.*

854px-apocrypta_guineensis2c_volw-wyfie_op_f_sur2c_manie_vd_schijff_bt2c_f

Apocrypta guineensis (a fig wasp). Photo by Wikimedia user JMK.**

You probably would pick the first one. And if I’d ask you which one deserves more attention and efforts to be preserved, you would likely choose the bird as well, or at least most people would. But what is the problem with that? That’s what I am going to show you now.

As we all know, the protection of biological diversity is an important subject in the current world. Fortunately, there is an increase in campaigns promoting the preservation of biodiversity, but unfortunately they are almost always directed to a small subset of species. You may find organizations seeking to protect sea turtles, tigers, eagles or giant pandas, but can you think of anyone wanting to protect beetles? Most preservation programs target large and charismatic creatures, such as mammals, birds and flowering plants, while smaller and not-so-cute organisms remain neglected. And this is not only true in environments that included non-biologist people, but in all fields of research. And more than only leading to a bias in the protection of ecosystems, this preference leads to thousands of understudied species that could bring biotechnological revolutions to humandkind.

In an interesting study published this week in Nature’s Scientific Reports (see reference below), Troudet et al. analyzed the taxonomic bias in biodiversity data by comparing the occurrence of data on several taxonomic groups to those groups’ diversity. The conclusions are astonishing, although not that much surprising. The most charismatic groups, such as birds, are, one could say, overstudied, with an excess of records, while other, such as insects, are highly understudied. While birds have about 200 million occurences above the ideal record, insects have about 200 million below the ideal number. And the situation does not seem to have improved very much along the years.

41598_2017_9084_fig1_html

The bias in interest is clear. The vertical line indicates the “ideal” number of occurrences of each group. A green bar indicates an excess of occurrences, while a red bar indicates a lack of occurrences. Birds and Insects are on the opposite extremes, but certainly the insect bias is much worse. Figure extracted from Troudet et al. (2017).***

Aditionally, the study concluded that the main reason for such disparity is simply societal preference, i.e., the most studied groups are the most loved ones by people in general. The issue is really a simple matter of charisma and has little to do with scientific or viability reasons.

The only way to change this scenario is if we find a way to raise awareness and interest of the general public on the less charismatic groups. We must make them interesting to the lay audience in order to receive their support and increase the number of future biologists that will choose to work with these neglected but very important creatures.

– – –

See also:

Once found and then forgotten: the not so bright side of taxonomy

The lack of taxonomists and its consequences on ecology

Unknown whereabouts: the lack of biogeographic references of species

– – –

Reference:

Troudet, J.; Grandcolas, P.; Blin, A,; Vignes-Lebbe, R.; Legendre, F. (2017) Taxonomic bias in biodiversity data and societal preferences. Scientific Report 7: 9132. https://dx.doi.org/10.1038/s41598-017-09084-6

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommerical-NoDerivs 2.0 Generic License.

**Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

***Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

1 Comment

Filed under Botany, Conservation, Systematics, taxonomy, Zoology

Friday Fellow: Operculate Acrochaete

by Piter Kehoma Boll

Last week I introduced a red alga, the Irish moss. Today I’m bringing another alga, this time a green one, but this is not an ordinary green alga, but a parasite of the Irish moss! So let’s talk about Acrochaete operculata, or the operculate acrochaete as I decided to call it in English, since obviously there would be no common name for an alga parasite of another alga.

Discovered and named in 1988, the operculate acrochaete is an exclusive parasite of Chondrus crispus. The infection occurs when flagellate zoospores of the parasite settle on the outer cell wall of the Irish Moss, where they start their development and digest the cell wall, penetrating the tissues of the host. In sporophytes of the Irish moss, the operculate acrochaete digests the intercellular matrix and spreads through the frond, while in gametophytes the infections remains localized, forming papules. The damages caused by the green alga lead to secondary infections by other organisms, especially bacteria, and the infected fronds end up falling apart, completely degradated.

ccrispus

A frond of the host (Chondrus crispus) to the left and the parasitic Acrochaete operculata that infects its tissues to the right. Photo extracted from chemgeo.uni-jena.de

As mentioned last week, the sporophytes and gametophytes of the Irish Moss have different forms of the polysaccharide carrageenan and this seems to be the reason why the parasite infects both forms differently. The sporophytes have lambda-carrageenan, which seems to increase the virulence of the parasite, while the kappa-carrageenan of the gametophyte seems to limit the green alga’s spread.

Since its discovery, the operculate acrochaete and its interaction with the Irish moss has been studied as a way to both reduce its damage on cultivated crops of the red alga and as a model to understand the relationship of plants and their pathogens.

– – –

References:

Bouarab, K.; Potin, P.; Weinberger, F.; Correa, J.; Kloareg, B. (2001) The Chondrus crispus-Acrochaete operculata host-pathogen association, a novel model in glycobiology and applied phycopathology. Journal of Applied Phycology 13(2): 185-193.

Correa, J. A.; McLachlan, J. L. (1993) Endophytic algae of Chondrus crispus (Rhodophyta). V. Fine structure of the infection by Acrochaete operculata (Chlorophyta). European Journal of Phycology 29(1): 33–47. http://dx.doi.org/10.1080/09670269400650461

Correa, J. A.; Nielsen, R.; Grund, D. W. (1988) Endophytic algae of Chondrus crispus (Rhodophyta). II. Acrochaete heteroclada sp. nov., A. operculata sp. nov., and Phaeophila dendroides (Chlorophyta). Journal of Phycology 24: 528–539. http://dx.doi.org/10.1111/j.1529-8817.1988.tb04258.x

 

Leave a comment

Filed under Algae, Botany, Disease, Friday Fellow, Parasites

Friday Fellow: Irish Moss

by Piter Kehoma Boll

Growing abundantly along the North Atlantic coasts, our newest Friday Fellow is a cartilaginous red alga commonly known as Irish moss or scientifically as Chondrus crispus, which means something like “curly cartilage”.

chondrus_crispus

The Irish moss usually appears as a mass of curly cartilaginous and soft seaweed with a red or purple tinge. Photo by Wikimedia user Kontos.*

Reaching about 20 cm in length, the Irish moss is attached to the substrate by a discoid base and its thallus branches dichotomously four or five times. The width of the branches may vary from about 2 to 15 mm and the color is even more variable, ranging from green or yellowish to dark red, purple, brown or even white. As with all plants, the Irish moss has a gametophyte (haploid) and a sporophyte (diploid) form. The gametophytes have a blue iridescence (as seen in the photo above), while the sporophytes show a dotted pattern (seen above as well).

The Irish moss is edible and relatively well known among the communities living where it grows. In Ireland and Scotland, it is boiled in milk and sweetened to produce a jelly-like product. The cartilaginous or jelly-like appearance of this alga and its derivatives are due to the presence of high amounts of carrageenan, a polysaccharide that is widely used in food industry as a thickening and stabilizing agent and as a vegan alternative to gelatin.

Due to its economic importance, the Irish moss is cultivated in tanks for the extraction of carrageenan and other products. Both gametophytes and sporophytes produce carrageenans of different types that can be used for different purposes.

– – –

References:

Chen, L. C.-M.; McLachlan, J. (1972) The life history of Chondrus crispus in culture. Canadian Journal of Botany 50(5): 1055–1060. http://doi.org/10.1139/b72-129

McCandless, E. L.; Craigie, J. S.; Walter, J. A. (1973) Carrageenans in the gametophytic and sporophytic stages of Chondrus crispus. Planta 112(3): 201–212.

Wikipedia. Chondrus crispus. Available at < https://en.wikipedia.org/wiki/Chondrus_crispus >. Access on August 1, 2017.

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

1 Comment

Filed under Algae, Botany, Friday Fellow

Friday Fellow: Spiked Pepper

by Piter Kehoma Boll

A relative of the famous black pepper from India that is used as a spice worldwide, today’s fellow, the spiked pepper Piper aduncum, comes from South America, where it is also called by other names such as matico and higuillo de hoja menuda.

Growing as a small tree or shrub, the spiked pepper is widespread throughout the continent, being found in both the Atlantic and the Amazonian forests. Having a peppery odor as other peppers, it can be used as a substitute of them while preparing food, but its main uses are medicinal.

Piper_aduncum

Close up of a branch of Piper aduncum showing the inflorescences. Photo by João Medeiros.*

It is classically used by local populations as an antiseptic applied directly on open wounds and also as an infusion or paste to treat gastrointestinal disorders and problems of the genital organs. Laboratory studies using extracts from the plant concluded that it has antibacterial and moluscidal properties, thus having the potential to be used as both an antiseptic and a pesticide against mollusks.

Outside of South America, the spiked pepper became a problematic invasive species in several islands of the Pacific, such as New Guinea and Fiji. In Papua-New Guinea, it has become so common that it was incorporated in the culture of local people, who use it as a wood source and as a medicine and pesticide.

– – –

References:

Maia, J., Zohhbi, M., Andrade, E., Santos, A., da Silva, M., Luz, A., & Bastos, C. (1998). Constituents of the essential oil ofPiper aduncum L. growing wild in the Amazon region Flavour and Fragrance Journal, 13 (4), 269-272 DOI: 10.1002/(SICI)1099-1026(1998070)13:43.0.CO;2-A

Orjala, J., Wright, A., Behrends, H., Folkers, G., Sticher, O., Rüegger, H., & Rali, T. (1994). Cytotoxic and Antibacterial Dihydrochalcones from Piper aduncum Journal of Natural Products, 57 (1), 18-26 DOI: 10.1021/np50103a003

Potzernheim, M., Bizzo, H., Silva, J., & Vieira, R. (2012). Chemical characterization of essential oil constituents of four populations of Piper aduncum L. from Distrito Federal, Brazil Biochemical Systematics and Ecology, 42, 25-31 DOI: 10.1016/j.bse.2011.12.025

Siges, T., Hartemink, A., Hebinck, P., & Allen, B. (2005). The Invasive Shrub Piper aduncum and Rural Livelihoods in the Finschhafen Area of Papua New Guinea Human Ecology, 33 (6), 875-893 DOI: 10.1007/s10745-005-8214-7

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution 2.0 Generic License.

Leave a comment

Filed under Botany, Friday Fellow

Friday Fellow: Field Hornwort

by Piter Kehoma Boll

Three weeks ago our Friday Fellow was a moss, being the third non-vascular plant to be introduced. And before going back to vascular plants, let’s take a look at another non-vascular fellow from the only non-vascular division that was not yet introduced here, the hornworts.

The species I chose to start the participation of hornworts is the field hornwort, Anthoceros agrestis.

Anthoceros_agrestis

A piece of soil with the field hornwort growing on the top. Photo by Wikimedia user BerndH.*

As with other hornworts, the field hornwort has a dominant gametophyte phase which appears as a small flattened plant growing very close to the soil. The sporophyte grows over it and has the form of an elongate vertical horn, hence the name hornwort.

Found in Europe and North America, the field hornwort usually grows in wet places and is often surrounded by  mosses. Its gametophyte has some internal cavities filled with muscilage that are a favorite place for species of cyanobacteria of the genus Nostoc to grow. This association is what makes hornworts acquire their slight bluish tinge.

The field hornwort has the smallest genome of all non-vascular plants studied until the present and because of that it has been cultivated to serve as an interesting model organism.

– – –

ResearchBlogging.orgReferences:

EOL – Encyclopedia of life. Field Hornwort. Available at <http://eol.org/pages/399515/overview&gt;. Access on May 18, 2017.

Szövényi, P., Frangedakis, E., Ricca, M., Quandt, D., Wicke, S., & Langdale, J. (2015). Establishment of Anthoceros agrestis as a model species for studying the biology of hornworts BMC Plant Biology, 15 (1) DOI: 10.1186/s12870-015-0481-x

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

Leave a comment

Filed under Botany, Friday Fellow