View source for Hypericum ×mitchellianum

{{Treatment/ID
|accepted_name=Hypericum ×mitchellianum
|accepted_authority=Rydberg
|publications={{Treatment/Publication
|title=Torreya
|place=27: 84, plate 2, figs. 1 – 6. 1927
|year=1927
}}
|common_names=Blue Ridge St. John’s wort
|special_status={{Treatment/ID/Special_status
|code=E
|label=Endemic
}}
|basionyms=
|synonyms=
|hierarchy=Hypericaceae;Hypericum;Hypericum sect. Hypericum;Hypericum ×mitchellianum
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Hypericaceae]]</div><div class="higher-taxon"><small>genus</small>[[Hypericum]]</div><div class="higher-taxon"><small>section</small>[[Hypericum sect. Hypericum]]</div><div class="higher-taxon"><small>species</small>[[Hypericum ×mitchellianum]]</div></div>
|volume=Volume 6
|mention_page=page 98, 100, 102
|treatment_page=page 101
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Herbs </b>erect, with rooting, creeping base, 2–6.5 dm. <b>Stems</b>: internodes usually 2-lined, sometimes 4-lined or not lined, with black glands scattered on and near lines or all over. <b>Leaves</b> spreading, usually sessile, rarely petiolate (to 0.8 mm); blade ovate-oblong to oblong or elliptic, 30–42(–52) × 8–22 mm, base subcordate to rounded, margins plane, apex usually rounded, rarely obtuse or subretuse, midrib with 4–5 pairs of branches, tertiary veins densely reticulate toward margins, black glands intramarginal (dense) and laminar (scattered). <b>Inflorescences</b> corymbiform to broadly pyramidal, (5–)13–61(–124)-flowered, subsidiary branches narrowly ascending or curved-ascending. <b>Flowers</b> 15–20 mm diam.; sepals not imbricate, erect in fruit, lanceolate to ovate-elliptic or elliptic, subequal, (3–)3.6–4.6(–5.5) × 1–2 mm, apex acute to obtuse; petals golden yellow, narrowly obovate or oblanceolate to elliptic, 6–11 mm; stamens (37–)42–56(–62); anther gland black; styles 1.5–5 mm. <b>Capsules</b> ellipsoid to subglobose, 3–7 × 3–4.5 mm, with longitudinal vittae. <b>Seeds</b> not carinate, 0.7–0.9 mm; testa not seen. <b>2n</b> = 16.</span><!--

-->{{Treatment/Body
|phenology=Flowering summer (Jun–Aug).
|habitat=Open or partly shaded, moist habitats, dry, rocky roadside banks
|elevation=1100–1700 m
|distribution=N.C.;Tenn.;Va.
|discussion=<p><i>Hypericum ×mitchellianum</i> is intermediate in all characters between <i>H. graveolens</i> and <i>H. punctatum</i> and, like the latter, produces a ring of 16 chromosomes at meiosis (D. E. Culwell 1970). Culwell has shown that it hybridizes with <i>H. graveolens</i> in the field and that these species can be crossed artificially. He apparently never suspected that H. mitchellianum could itself be a hybrid. Its intermediate morphology and breeding behavior, together with a distribution almost wholly within that of <i>H. graveolens</i>, suggests strongly that H. mitchellianum is the hybrid <i>H. graveolens</i> × punctatum, which apparently arose when the area of <i>H. punctatum</i> extended into that of <i>H. graveolens</i>.</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Hypericum ×mitchellianum
|author=
|authority=Rydberg
|rank=species
|parent rank=section
|synonyms=
|basionyms=
|family=Hypericaceae
|phenology=Flowering summer (Jun–Aug).
|habitat=Open or partly shaded, moist habitats, dry, rocky roadside banks
|elevation=1100–1700 m
|distribution=N.C.;Tenn.;Va.
|reference=None
|publication title=Torreya
|publication year=1927
|special status=Endemic
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f6b125a955440c0872999024f038d74684f65921/coarse_grained_fna_xml/V6/V6_178.xml
|genus=Hypericum
|section=Hypericum sect. Hypericum
|species=Hypericum ×mitchellianum
}}<!--

-->[[Category:Treatment]][[Category:Hypericum sect. Hypericum]]