View source for Epilobium sect. Pachydium

{{Treatment/ID
|accepted_name=Epilobium sect. Pachydium
|accepted_authority=(Fischer & C. A. Meyer) Hoch & K. Gandhi
|publications={{Treatment/Publication
|title=PhytoKeys,
|place=145: 60. 2020
|year=2020
}}
|basionyms={{Treatment/ID/Basionym
|name=Oenothera sect. Pachydium
|authority=Fischer & C. A. Meyer
|rank=section
|publication_title=Index Seminum (St. Petersburg)
|publication_place=2: 45.  1836
}} {{Treatment/ID/Basionym
|name=Boisduvalia
|authority=Spach
|rank=genus
|publication_title=Hist. Nat. Vég.
|publication_place=4: 383.  1835
}}
|synonyms={{Treatment/ID/Synonym
|name=Boisduvalia
|authority=[unranked] Dictyopetalum (Fischer & C. A. Meyer) Endlicher
|rank=genus
}} {{Treatment/ID/Synonym
|name=Boisduvalia
|authority=[unranked] Pachydium (Fischer & C. A. Meyer) Endlicher
|rank=genus
}} {{Treatment/ID/Synonym
|name=Boisduvalia subg. Pachydium
|authority=(Fischer & C. A. Meyer) Reichenbach
|rank=subgenus
}} {{Treatment/ID/Synonym
|name=Cratericarpium
|authority=Spach
|rank=genus
}} {{Treatment/ID/Synonym
|name=Epilobium sect. Boisduvalia
|authority=(Spach) Hoch & P. H. Raven
|rank=section
}} {{Treatment/ID/Synonym
|name=Dictyopetalum
|authority=(Fischer & C. A. Meyer) Baillon
|rank=genus
}} {{Treatment/ID/Synonym
|name=Oenothera
|authority=[unranked] Boisduvalia (Spach) Torrey & A. Gray
|rank=genus
}} {{Treatment/ID/Synonym
|name=Oenothera sect. Dictyopetalum
|authority=Fischer & C. A. Meyer
|rank=section
}}
|hierarchy=Onagraceae;Onagraceae subfam. Onagroideae;Onagraceae tribe Epilobieae;Epilobium;Epilobium sect. Pachydium
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Onagraceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Onagraceae subfam. Onagroideae]]</div><div class="higher-taxon"><small>tribe</small>[[Onagraceae tribe Epilobieae]]</div><div class="higher-taxon"><small>genus</small>[[Epilobium]]</div><div class="higher-taxon"><small>section</small>[[Epilobium sect. Pachydium]]</div></div>
|volume=Volume 10
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-d0_s0" data-properties=""><b>Herbsannual,</b> with taproot.</span> <span class="statement" id="st-d0_s1" data-properties=""><b>Stems:</b> epidermis peeling proximally.</span> <span class="statement" id="st-d0_s2" data-properties="leaf arrangement;leaf duration;leaf arrangement"><b>Leaves </b>opposite and early deciduous in proximal pairs, alternate distally.</span> <span class="statement" id="st-d0_s3" data-properties="flower architecture;flower reproduction;flower reproduction"><b>Flowers </b>actinomorphic, chasmogamous or rarely cleistogamous;</span> <span class="statement" id="st-d0_s4" data-properties="floral-tube architecture">floral-tube not bulbous, without scales inside;</span> <span class="statement" id="st-d0_s5" data-properties="petal coloration;petal coloration;petal coloration">petals rose-purple to white;</span> <span class="statement" id="st-d0_s6" data-properties="">pollen in tetrads;</span> <span class="statement" id="st-d0_s7" data-properties="stigma shape;stigma architecture or shape;stigma shape">stigma clavate, entire or sometimes obscurely 4-lobed.</span> <span class="statement" id="st-d0_s8" data-properties="capsule shape;capsule shape;capsule shape;capsule shape;capsule architecture or dehiscence;central column duration;central column duration;central column architecture"><b>Capsules </b>fusiform-clavate to lanceolate-linear, sometimes torulose, splitting to base, central column persistent or not, sessile.</span> <span class="statement" id="st-d0_s9" data-properties="seed quantity;seed shape;row quantity;row quantity;row quantity"><b>Seeds </b>2–8 per locule in 1 row, or 8–12 per capsule, pushed into a single row by disintegration of central column and septa, irregularly angular-fusiform;</span> <span class="statement" id="st-d0_s10" data-properties="coma presence">coma absent.</span><!--

-->{{Treatment/Body
|distribution=w North America;nw Mexico;w South America
|discussion=<p>Species 4 (3 in the flora).</p><!--
--><p>Section Pachydium consists of four self-compatible, often cleistogamous, annual species, two of which are endemic to and widespread in western North America, and a third that also reaches northern Mexico. Epilobium subdentatum (Meyen) Lievens & Hoch, occurs only in Chile (widespread) and Argentina (only in Chubut Province), and has larger, often outcrossing flowers pollinated by bees (P. H. Raven and D. M. Moore 1965). The species in sect. Pachydium are diverse cytologically: E. torreyi has the lowest chromosome number in Epilobieae (n = 9), E. densiflorum and E. pallidum have n = 10, and E. subdentatum has n = 19. Contrary to suggestions by G. L. Stebbins (1971) and Raven (1976), the numbers n = 9 and 10 apparently were derived as direct or stepwise aneuploid reductions from the paleotetraploid x = 18 base number for Epilobieae (D. A. Baum et al. 1994). Experimental hybrids were formed in all combinations among the four species, although most had notably aberrant chromosome pairing and very low pollen fertility (S. R. Seavey 1992). The so-called tetraploid E. subdentatum (n = 19) apparently arose following hybridization between E. torreyi (n = 9) and E. densiflorum or a close relative with n = 10 (Seavey), followed by long-distance dispersal to South America (Raven and Moore). The monophyly of the section is scarcely supported by analysis of ITS sequence (Baum et al.), and the exact relationship of these species is not well-resolved.</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Epilobium sect. Pachydium
|authority=(Fischer & C. A. Meyer) Hoch & K. Gandhi
|rank=section
|parent rank=genus
|synonyms=Boisduvalia;Boisduvalia;Boisduvalia subg. Pachydium;Cratericarpium;Epilobium sect. Boisduvalia;Dictyopetalum;Oenothera;Oenothera sect. Dictyopetalum
|basionyms=Oenothera sect. Pachydium;Boisduvalia
|family=Onagraceae
|distribution=w North America;nw Mexico;w South America
|reference=None
|publication title=PhytoKeys,
|publication year=2020
|special status=
|source xml=
|subfamily=Onagraceae subfam. Onagroideae
|tribe=Onagraceae tribe Epilobieae
|genus=Epilobium
|section=Epilobium sect. Pachydium
|capsule architecture or dehiscence=splitting
|capsule shape=torulose;fusiform-clavate;lanceolate-linear
|central column architecture=sessile
|central column duration=not;persistent
|coma presence=absent
|floral-tube architecture=not bulbous
|flower architecture=actinomorphic
|flower reproduction=cleistogamous;chasmogamous
|leaf arrangement=alternate;opposite
|leaf duration=deciduous
|petal coloration=rose-purple;white
|row quantity=single;8;12
|seed quantity=2;8
|seed shape=angular-fusiform
|stigma architecture or shape=entire
|stigma shape=4-lobed;clavate
}}<!--

-->[[Category:Treatment]][[Category:Epilobium]]