View source for Empetrum

{{Treatment/ID
|accepted_name=Empetrum
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=2: 1022. 1753
|year=1753
}}, {{Treatment/Publication
|title=Gen. Pl. ed.
|place=5, 447. 1754 ,
}}
|common_names=Crowberry;camarine
|basionyms=
|synonyms=
|hierarchy=Ericaceae;Ericaceae subfam. Ericoideae;Empetrum
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Ericaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Ericaceae subfam. Ericoideae]]</div><div class="higher-taxon"><small>genus</small>[[Empetrum]]</div></div>
|etymology=Greek en-, in, and petros, rock, alluding to habitat
|volume=Volume 8
|mention_page=page 374, 375, 487, 489, 490
|treatment_page=page 486
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Shrubs.</b> Stems prostrate, trailing, (densely branched, 0.5–1 m, woody); branchlets glabrous or sparsely to densely hairy or glandular distally. <b>Leaves</b> persistent, whorled or spirally arranged; petiole present, (very short); blade (lustrous or opaque, linear, oblong, or elliptic), coriaceous, margins entire, (strongly revolute, enclosing abaxial surface and forming waxy stomatal cavity appearing as groove, surfaces glabrous, glandular, or hairy). <b>Inflorescences</b> solitary flowers (borne on short shoots from axils of distal leaves); perulae absent. <b>Flowers</b> unisexual or bisexual (plants synoecious, sometimes polygamous, or dioecious), radially symmetric; sepals 3, distinct, (oblong); petals 3, (white), corolla deciduous (hence reports of apetalous flowers), oblanceoloid; stamens (2–)4(–6) (staminate flowers usually with 3 stamens), exserted; anthers without awns, dehiscent from slits; ovary 6–9-locular; style exserted; stigma branched. <b>Fruits</b> drupaceous, globose, fleshy, enclosed by nonfleshy calyx. <b>Seeds</b> 6–9, ovoid, not winged, not tailed; testa smooth or with minute spicules. <b>x</b> = 13.</span><!--

-->{{Treatment/Body
|distribution=North America;s South America;n Eurasia;s Atlantic Islands;circumboreal;low arctic;alpine;bipolar.
|discussion=<p>Species 3–18 (3 in the flora).</p><!--
--><p>Comprehensive taxonomies of <i>Empetrum</i> are relatively few and none is recent (e.g., R. Good 1927; V. N. Vassiljev 1961). <i>Empetrum</i> in North America has been treated regionally, especially in northeastern North America, without consideration of the problems faced continent-wide, and without a unified taxonomy that addresses the variation elsewhere. In his circumpolar review, E. Hultén (1971) wrote of <i>Empetrum</i>: “A...complex, where different authors rarely, if ever, arrive at the same conclusion.” He remarked that the genus <i>Empetrum</i> could be considered to comprise a single, variable species. Vassiljev, on the other hand, proposed 18 species worldwide, ten for North America including Greenland.</p><!--
--><p><i>Empetrum</i> is monophyletic (A. A. Anderberg 1994c; Li J. H. et al. 2002; M. Popp et al., unpubl.). Analyses of morphology (Anderberg) and molecular genetics (Li et al.; Popp et al.) have shown relationships to other closely related ericads, congeners, and to some extent within <i>Empetrum</i>. Using molecular methods, V. Mirré (2004) using amplified fragment length polymorphism (AFLP) and Popp et al. using plastid trnS–trnfM and trnS–trnG and nuclear RPB2 and RPC2 sequences have, in preliminary studies, evaluated relationships among taxa, but without finding sufficient structure to create a new taxonomy. However, these studies tell us that assumptions about key characters in the treatment by V. N. Vassiljev (1961), for example, are not well supported by molecular data, and we cannot, therefore, simply accept and repeat entirely what is in previous, albeit monographic, treatments.</p><!--
--><p>A. A. Anderberg (1994c) and V. Mirré (2004) found good separation of the red-fruited Southern Hemisphere plants (<i>Empetrum</i> rubrum Vahl ex Willdenow), although Li J. H. et al. (2002) and M. Popp et al. (unpubl.) did not. Nevertheless, we are treating E. rubrum as distinct from all North American taxa. Popp et al. did find that red-fruited, diploid <i>E. eamesii</i> was well separated from other taxa in the region, whereas, in terms of molecular genetics, the Southern Hemisphere red-fruited diploid E. rubrum has its closest connections in the Northern Hemisphere not to <i>E. eamesii</i> but to black-fruited Northern Hemisphere plants treated here as <i>E. nigrum</i> in the broad sense. The solution is to recognize the diploid <i>E. eamesii</i>, the diploid and tetraploid <i>E. nigrum</i>, and <i>E. atropurpureum</i> as a possible allotetraploid from diploid <i>E. eamesii</i> and a diploid <i>E. nigrum</i>. This leaves a great deal of variation within <i>E. nigrum</i> in the broad sense unaccounted for. Various hybrid combinations were alleged by D. Löve (1960); these require confirmation. For the most part, as there are exceptions, diploid taxa are normally dioecious and tetraploids are normally synoecious but sometimes polygamous.*</p><!--
--><p>* The authors kindly wish to acknowledge the unpublished information provided by John Maunder, Pierre Morrisett, and Peter Zika on the northeastern endemic taxa of <i>Empetrum</i> for the flora area.</p>
|tables=
|references={{Treatment/Reference
|id=anderberg1994a
|text=Anderberg, A. A. 1994c. Phylogeny of the Empetraceae, with special emphasis on character evolution in the genus Empetrum. Syst. Bot. 19: 35–46.
}}{{Treatment/Reference
|id=good1927a
|text=Good, R. 1927. The genus Empetrum L. J. Linn. Soc., Bot. 47: 489–523.
}}{{Treatment/Reference
|id=li2002a
|text=Li, J. H. et al. 2002. Phylogenetic relationships of Empetraceae inferred from sequences of chloroplast gene matK and nuclear ribosomal DNA ITS region. Molec. Phylogen. Evol. 25: 306–315.
}}{{Treatment/Reference
|id=mirre2004a
|text=Mirré, V. 2004. Phylogeny, Migration and Evolution of a Bipolar Model Group: The Genus Empetrum (Crowberries). C.S. thesis. University of Oslo.
}}{{Treatment/Reference
|id=vassiljev1961a
|text=Vassiljev, V. N. 1961. Rod Empetrum. Moscow.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Branches distally glabrous or sparsely tomentose, eglandular or glandular; drupes black.
|[[Empetrum nigrum|Empetrum nigrum]]
|-id=key-0-1
|1
|Branches distally white-tomentose, eglandular; drupes pink, red, reddish purple, or purple
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Drupes pink or red, translucent; flowers unisexual; plants dioecious.
|[[Empetrum eamesii|Empetrum eamesii]]
|-id=key-0-2
|2
|Drupes purple or reddish purple, opaque; flowers usually bisexual; plants synoecious; when flowers unisexual, plants polygamous.
|[[Empetrum atropurpureum|Empetrum atropurpureum]]
|}
</div></div><!--

-->{{#Taxon:
name=Empetrum
|author=David F. Murray;Virginia Mirré;Reidar Elven
|authority=Linnaeus
|rank=genus
|parent rank=subfamily
|synonyms=
|basionyms=
|family=Ericaceae
|distribution=North America;s South America;n Eurasia;s Atlantic Islands;circumboreal;low arctic;alpine;bipolar.
|reference=anderberg1994a;good1927a;li2002a;mirre2004a;vassiljev1961a
|publication title=Sp. Pl.;Gen. Pl. ed.
|publication year=1753;
|special status=
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V8/V8_951.xml
|subfamily=Ericaceae subfam. Ericoideae
|genus=Empetrum
}}<!--

-->[[Category:Treatment]][[Category:Ericaceae subfam. Ericoideae]]