Byblis (plant): Difference between revisions

{{More footnotes needed|date=November 2021}}

|parent_authority = [[Karel Domin|Domin]]<ref name="apgiii">{{Citation |last=Angiosperm Phylogeny Group |year=2009 |title=An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III |journal=Botanical Journal of the Linnean Society |volume=161 |issue=2 |pages=105–121 |doi=10.1111/j.1095-8339.2009.00996.x |doi-access=free |hdl=10654/18083 |hdl-access=free }}</ref>

'''''Byblis''''' ({{IPAc-en|ˈ|b|ɪ|b|l|ᵻ|s}} {{respell|BIB|liss}}) is a small [[genus]] of [[carnivorous plant]]s, sometimes termed the '''rainbow plants''' for the attractive appearance of their [[mucilage]]-covered [[Leaf|leaves]] in bright sunshine. Native to [[Australia]] and [[New Guinea]],<ref>{{cite web |title=Byblis Salisb. {{!}} Plants of the World Online {{!}} Kew Science |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:14417-1 |website=Plants of the World Online |language=en}}</ref> it is the only genus in the family '''Byblidaceae'''. The first species in the genus was described by the English botanist [[Richard Anthony Salisbury]] in 1808. Eight species are now recognised (see below).

All species of the genus form upright growth supported by a weak, fibrous root system. The genus can be divided into two groups or "complexes": The ''B. liniflora'' complex and the ''B. gigantea'' complex (see [[#Subdivision of the genus|below]]).

The leaves of all species are round in cross section and highly elongated, tapering at the end. The surface of the leaves is densely studded with glandular hairs which secrete a [[mucilage|mucilaginous]] substance from their tip. These serve to attract small [[insect]]s, which upon touching the sticky secretions are ensnared. Unless they are strong enough to escape, the insect prey either die of exhaustion or [[asphyxiate]] as the mucilage envelops them and clogs their [[Spiracle (arthropods)|spiracles]]. Unlike the sundews, however, ''Byblis'' can move neither their tentacles nor the leaves themselves to aid trapping or digestion. As a result, they are grouped among the "passive flypaper traps" along with ''[[Pinguicula]]'', ''[[Drosophyllum]]'', ''[[Roridula]]'', ''[[Stylidium]]'' and ''[[Triphyophyllum peltatum]]''.

[[Flowers]] in this genus are borne singly at the end of unbranching, leaf-like [[inflorescence]]s which emerge from the leaf axils. The five-petaled flowers are generally purple to pale violet, though ''B. gigantea'' and ''B. filifolia'' can sometimes produce white flowers. Except for the self-fertile ''B. liniflora'', all species require [[pollen]] from other individuals for [[Flower#Fertilization|fertilization]]. The pollen release of ''B. gigantea'' and ''B. lamellata'' is only triggered by the [[resonance frequency]] of the wings of a landing pollinator, helping ensure cross-pollination with other individuals. The flowers of ''Byblis'' start to bloom in early spring and last until late summer.

Like many [[carnivorous plants]], ''Byblis'' species usually grow in [[bog]]s and [[marsh]]es. They generally prefer seasonally wet sandy soil in partial or direct sunlight with temperatures between ~ {{convert|5|-|40&nbsp;°|C (40-105&nbsp;°|F)}}.

The status of the genus as a truly [[carnivorous plant]] has been repeatedly put into question. In their natural habitat, all species have been observed playing host to live [[Hemiptera|bug]]s of the genus ''[[Setocoris]]'', which nourished themselves by eating prey caught by the plants. Following this discovery it was assumed that, as with the genus ''[[Roridula]]'', the plants do not actually digest their prey themselves, rather relying on the bugs to do that. The plants, it was reasoned, benefited by absorbing nutrients from the excrements of the bugs, either through their leaves or through the ground. An indirect digestion of these nutrients by a [[chitinase]] producing [[fungus]] was even proposed. It was not until 2005 that direct digestion of insect prey by enzymes secreted by the sessile glands of ''B. filifolia'' was proven.<ref>{{cite journal|last1=Hartmeyer, |last2=Irmgard und |last3=Siegfried: |title=''Byblis filifolia'' als echte Karnivore rehabilitiert'', |journal=Das Taublatt (GFP), |volume=53, 4-5, |issue=4–5|year=2005}}</ref> Soon thereafter similar results were found with ''B. liniflora''. These results clearly place this genus among the true carnivorous plants.

The four species of this complex, ''B. liniflora'', ''B. rorida'', ''B. filifolia'' and ''B. aquatica'', are [[annual plant|annual]] [[herbaceous]] plants that reach a height of {{convertcvt|15|-|50|cm|in|abbr=on}} and a maximum leaf length of {{convertcvt|4|-|15|cm|in|abbr=on}}. These species grow from seedlings to flowering plants in only a few months, setting seed and dying with the onset of the dry season. The original [[haploid]] [[chromosome]] count of this complex is x=8. The [[diploid]] number is therefore 2n=16, whereas the [[polyploid|tetraploid]] species ''B. liniflora'' is 2n=32.

The remaining two species, ''B. lamellata'' und ''B. gigantea'', make up what is known as the ''B. gigantea'' complex. These perennial species are both [[endemism|endemic]] to [[Southwest Australia]], and reach heights of {{convertcvt|45|-|70|cm|in|abbr=on}}. Unlike the annual members of the ''B. liniflora'' complex, these species survive the dry season by dying back to an underground [[rhizome]], out of which they emerge come fall. The leaves of this complex can reach {{convert|20|cm|in|abbr=on}} in length. The base chromosome count of the complex is x=9; since both species are diploid, their chromosome count is 2n=18.

In the year 2004 a single fossil of a seed, resembling that of members of the modern day ''B. liniflora'' complex, was discovered in south Australia dating from the middle of the [[Eocene]] epoch. The species was assigned to the Byblidaceae as a [[parataxon]] of the genus.<ref name="Conran2004">{{cite journal |last1=Conran |first1=John G. |last2=Christophel |first2=David C. |title=A Fossil Byblidaceae Seed from Eocene South Australia |journal=International Journal of Plant Sciences |date=2004 |volume=165 |issue=4 |pages=691–694 |doi=10.1086/386555|hdl=2440/1805 |s2cid=32159540 |hdl-access=free }}</ref> The sole specimen was unfortunately destroyed in a lab accident shortly after being photographed.<ref name="Conran2004"/><ref>{{cite journal |last1=Givnish |first1=Thomas J. |title=New evidence on the origin of carnivorous plants |journal=Proceedings of the National Academy of Sciences |date=2015 |volume=112 |issue=1 |pages=10–11 |doi=10.1073/pnas.1422278112|pmid=25538295 |pmc=4291624 |doi-access=free |bibcode=2015PNAS..112...10G }}</ref>

== References ==

* Conran, John G.; Houben, Andreas; Lowrie, Allen: ''Chromosome numbers in Byblidaceae'', Aust. J. Bot., 2002, 50, 583-586583–586

* Fukushima, K., K. Imamura, K. Nagano & Y. Hoshi (2011). {{cite journal|title=Contrasting patterns of the 5S and 45S rDNA evolutions in the ''Byblis liniflora'' complex (Byblidaceae). |doi=10.1007/s10265-010-0366-x |pmid=20623155 |pmc=3040357 |year=2011 |last1=Fukushima |first1=Kenji |last2=Imamura |first2=Kaori |last3=Nagano |first3=Katsuya |last4=Hoshi |first4=Yoshikazu |journal=Journal of Plant Research |volume=124 |issue=2 |pages=231–244 |bibcode=2011JPlR..124..231F }} ''Journal of Plant Research'' '''124'''(2): 231–244. {{doi|10.1007/s10265-010-0366-x}}