{{short description|Species of flowering plants in the rock rose family Cistaceae}} {{Speciesbox |taxon = Cistus horrens |image = Cistus horrens.jpg |authority = Demoly<ref name=TPL_kew-2723437/> }}

'''''Cistus horrens''''' is a [[shrub]]by [[species]] of [[flowering plant]] in the family [[Cistaceae]], with purple to pink flowers. It is [[Endemism|endemic]] to [[Gran Canaria]] in the [[Canary Islands]]. First described as a species in 2004, it was previously identified as ''[[Cistus symphytifolius]]'', which it resembles.

==Description== ''Cistus horrens'' generally resembles the more widespread ''[[Cistus symphytifolius]]''. Differences include young branches covered with simple hairs; leaf blades grayer and shorter, densely covered with simple, glandular and stellate hairs on the upper surface and with longer simple hairs on the lower surface, with glandular hairs only on the nerves; sepals densely covered with simple hairs; and smaller fruiting capsules with fewer seeds.<ref name=JBVC/> The leaves are elliptical to lanceolate, stalked ([[Petiole (botany)|petiolate]]) and have netted (reticulate) veins. The stigmas are longer than the stamens.<ref name=GuzmVarg10/>

==Taxonomy and phylogeny== ''Cistus horrens'' was first described as a new species by Jean-Pierre Demoly in 2004;<ref name=TPL_kew-2723437/> it had previously been treated as ''C.&nbsp;symphytifolius''.<ref name=JBVC/> The specific epithet ''horrens'' is [[Latin]] for "standing erect, bristling".<ref name=LWST/>

A 2011 [[Molecular phylogenetics|molecular phylogenetic study]] placed ''C.&nbsp;horrens'' as a member of the purple and pink flowered clade (PPC) of ''Cistus'' species, along with some other Canary Island endemics (''[[Cistus asper]]'', ''[[Cistus chinamadensis]]'', ''[[Cistus ocreatus]]'', and ''[[Cistus symphytifolius]]'').<ref name=CiveLeclDemoAgna11/>

{{cladogram |title=Species-level cladogram of ''Cistus'' species. |caption=Species-level cladogram of ''Cistus'' species, based on [[Chloroplast DNA|plastid]] and [[nuclear DNA]] sequences.<ref name=CiveLeclDemoAgna11 /><ref name=GuzmVarg09>{{cite journal |last1=Guzmán |first1=B. |last2=Vargas |first2=P. |date=2009 |title=Historical biogeography and character evolution of Cistaceae (Malvales) based on analysis of plastid rbcL and trnL-trnF sequences |journal=Organisms Diversity & Evolution |volume=9 |issue=2 |pages=83–99 |doi=10.1016/j.ode.2009.01.001 |name-list-style=amp}}</ref><ref name=GuzmVarg05>{{citation |last1=Guzmán |first1=B. |last2=Vargas |first2=P. |year=2005 |title=Systematics, character evolution, and biogeography of ''Cistus'' L. (Cistaceae) based on ITS, trnL-trnF, and matK sequences |journal=Molecular Phylogenetics and Evolution |volume=37 |issue=3 |pages=644–660 |doi=10.1016/j.ympev.2005.04.026 |name-list-style=amp |pmid=16055353}}</ref><ref name=GuzmLled09>{{cite journal |last1=Guzman |first1=B. |last2=Lledo |first2=M.D. |last3=Vargas |first3=P. |year=2009 |title=Adaptive Radiation in Mediterranean ''Cistus'' (Cistaceae) |journal=PLOS ONE |volume=4 |issue=7 |article-number=e6362 |doi=10.1371/journal.pone.0006362 |name-list-style=amp |pmid=19668338 |pmc=2719431|bibcode=2009PLoSO...4.6362G |doi-access=free }}</ref> |align=center |clades={{Cladogram of Cistus species}} }}

==Distribution and habitat== ''Cistus horrens'' is [[Endemism|endemic]] to [[Gran Canaria]] in the [[Canary Islands]],<ref name=GuzmVarg10/> being found in the south-west sector of the island.<ref name=JBVC/> It is typically found at elevations of {{convert|300|–|1500|m|ft|-2}} in pine forests, in semiarid conditions.<ref name=GuzmVarg10/>

==References== {{Reflist|refs= <ref name=CiveLeclDemoAgna11>{{Citation |last1=Civeyrel |first1=Laure |last2=Leclercq |first2=Julie |last3=Demoly |first3=Jean-Pierre |last4=Agnan |first4=Yannick |last5=Quèbre |first5=Nicolas |last6=Pélissier |first6=Céline |last7=Otto |first7=Thierry |year=2011 |title=Molecular systematics, character evolution, and pollen morphology of Cistus and Halimium (Cistaceae) |journal=Plant Systematics and Evolution |volume=295 |issue=1–4 |pages=23–54 |doi=10.1007/s00606-011-0458-7 |s2cid=21995828 |name-list-style=amp |hdl=2078.1/219851 |hdl-access=free }}</ref>

<ref name=JBVC>{{citation |title=''Cistus horrens'' Demoly |website=Jardín Botánico Viera y Clavijo |url=http://www.jardincanario.org/-/especie-cistus-horrens-demoly |publisher=Cabildo de Gran Canaria |language=Spanish |access-date=2015-03-13 }}</ref>

<ref name=GuzmVarg10>{{Citation |last1=Guzmán |first1=Beatriz |last2=Vargas |first2=Pablo |year=2010 |title=Unexpected synchronous differentiation in Mediterranean and Canarian ''Cistus'' (Cistaceae) |journal=Perspectives in Plant Ecology, Evolution and Systematics |volume=12 |issue=3 |pages=163–174 |doi=10.1016/j.ppees.2009.09.002 |name-list-style=amp }}, p. 167</ref>

<ref name=LWST>{{citation |title=''horreo'' |website=Latin Word Study Tool |url=https://www.perseus.tufts.edu/hopper/morph?l=horrens&la=la |access-date=2015-03-14 |publisher=Tufts University }}</ref>

<ref name=TPL_kew-2723437>{{citation |title=''Cistus horrens'' |work=The Plant List |url=http://www.theplantlist.org/tpl1.1/record/kew-2723437 |access-date=2015-03-02}}</ref> }}

{{Taxonbar|from=Q15330314}}

[[Category:Cistus|horrens]] [[Category:Plants described in 2004]] [[Category:Endemic flora of the Canary Islands]] [[Category:Flora of Gran Canaria]]