View source for Psilactis tenuis

{{Treatment/ID
|accepted_name=Psilactis tenuis
|accepted_authority=S. Watson
|publications={{Treatment/Publication
|title=Proc. Amer. Acad. Arts
|place=26: 139. 1891
|year=1891
}}
|special_status={{Treatment/ID/Special_status
|code=F
|label=Illustrated
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Machaeranthera tenuis
|authority=(S. Watson) B. L. Turner & D. B. Horne
|rank=species
}}
|hierarchy=Asteraceae;Asteraceae tribe Astereae;Psilactis;Psilactis tenuis
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Astereae]]</div><div class="higher-taxon"><small>genus</small>[[Psilactis]]</div><div class="higher-taxon"><small>species</small>[[Psilactis tenuis]]</div></div>
|volume=Volume 20
|mention_page=page 462
|treatment_page=page 463
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole-organism some measurement;whole-organism duration;whole-organism some measurement;whole-organism duration"><b>Annuals </b>or biennials, 25–100 cm.</span> <span class="statement" id="st-d0_s1" data-properties="stem orientation;stem pubescence;stem pubescence or relief;stem pubescence;branch orientation;branch pubescence;branch pubescence or relief;branch pubescence"><b>Stems </b>and branches coarsely antrorse or erect-hairy, often scabrous, usually stipitate-glandular distally, sometimes proximally.</span> <span class="statement" id="st-d0_s2" data-properties="distal leaf-blade architecture;distal leaf-blade shape;distal leaf-blade arrangement;distal leaf-blade arrangement;distal leaf-blade size;distal leaf-blade length;distal leaf-blade width"><b>Distal </b>leaf-blades sessile, linear-lanceolate to narrowly elliptic or linear, smallest 3–4 × 1–1.5 mm.</span> <span class="statement" id="st-d0_s3" data-properties="involucre shape;involucre some measurement"><b>Involucres </b>broadly turbinate, 4–6 mm.</span> <span class="statement" id="st-d0_s4" data-properties="phyllarie shape;phyllarie variability;phyllarie size;phyllarie length;phyllarie width;base texture;margin texture"><b>Phyllaries </b>linear-lanceolate to linear, equal or slightly unequal, 2.5–5 × 0.3–0.6 mm, bases indurate, margins scarious.</span> <span class="statement" id="st-d0_s5" data-properties="receptacle shape;receptacle diameter"><b>Receptacles </b>convex, 1.8–2.5 mm diam.</span> <span class="statement" id="st-d0_s6" data-properties="ray-floret quantity"><b>Ray-</b>florets 10–35;</span> <span class="statement" id="st-d0_s7" data-properties="lamina length;lamina width">laminae 5–8 × 0.7–1 mm.</span> <span class="statement" id="st-d0_s8" data-properties="disc-floret quantity"><b>Disc-</b>florets 20–55;</span> <span class="statement" id="st-d0_s9" data-properties="corolla some measurement">corollas 3–4 mm.</span> <span class="statement" id="st-d0_s10" data-properties="ray cypsela some measurement;ray cypsela pubescence"><b>Ray </b>cypselae 1.2–1.7 mm, sparsely appressed-hairy.</span> <span class="statement" id="st-d0_s11" data-properties="disc cypsela some measurement;disc cypsela pubescence"><b>Disc </b>cypselae 1.5–2.5 mm, sparsely appressed-hairy;</span> <span class="statement" id="st-d0_s12" data-properties="pappus some measurement;pappus some measurement;2n chromosome quantity">pappi 20–35, 2.5–4 mm. <b>2n</b> = 8.</span><!--

-->{{Treatment/Body
|phenology=Flowering (May–)Aug–Oct.
|habitat=Calcareous soils in open oak and pine-oak woodlands, rocky streambeds
|elevation=1700–2600 m
|distribution=Tex.;Mexico (Coahuila);Mexico (Nuevo León);Mexico (Tamaulipas);Mexico (Zacatecas)
|discussion=<p>In the flora area, Psilactis tenuis is known only from the Davis Mountains. Because of its distribution in Mexico, it would be expected to occur in additional areas to the southeast of the Davis Mountains, such as the Glass Mountains and Chisos Mountains. Apparently no records of it exist from those areas.</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Psilactis tenuis
|authority=S. Watson
|rank=species
|parent rank=genus
|synonyms=Machaeranthera tenuis
|basionyms=
|family=Asteraceae
|phenology=Flowering (May–)Aug–Oct.
|habitat=Calcareous soils in open oak and pine-oak woodlands, rocky streambeds
|elevation=1700–2600 m
|distribution=Tex.;Mexico (Coahuila);Mexico (Nuevo León);Mexico (Tamaulipas);Mexico (Zacatecas)
|reference=None
|publication title=Proc. Amer. Acad. Arts
|publication year=1891
|special status=Illustrated
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V19-20-21/V20_1070.xml
|tribe=Asteraceae tribe Astereae
|genus=Psilactis
|species=Psilactis tenuis
|2n chromosome quantity=8
|base texture=indurate
|branch orientation=antrorse
|branch pubescence=stipitate-glandular;erect-hairy
|branch pubescence or relief=scabrous
|corolla some measurement=3mm;4mm
|disc cypsela pubescence=appressed-hairy
|disc cypsela some measurement=1.5mm;2.5mm
|disc-floret quantity=20;55
|distal leaf-blade architecture=sessile
|distal leaf-blade arrangement=linear;elliptic
|distal leaf-blade length=3mm;4mm
|distal leaf-blade shape=linear-lanceolate
|distal leaf-blade size=smallest
|distal leaf-blade width=1mm;1.5mm
|involucre shape=turbinate
|involucre some measurement=4mm;6mm
|lamina length=5mm;8mm
|lamina width=0.7mm;1mm
|margin texture=scarious
|pappus some measurement=20;35
|phyllarie length=2.5mm;5mm
|phyllarie shape=linear-lanceolate;linear
|phyllarie size=unequal
|phyllarie variability=equal
|phyllarie width=0.3mm;0.6mm
|ray cypsela pubescence=appressed-hairy
|ray cypsela some measurement=1.2mm;1.7mm
|ray-floret quantity=10;35
|receptacle diameter=1.8mm;2.5mm
|receptacle shape=convex
|stem orientation=antrorse
|stem pubescence=stipitate-glandular;erect-hairy
|stem pubescence or relief=scabrous
|whole-organism duration=biennial;annual
|whole-organism some measurement=25cm;100cm
}}<!--

-->[[Category:Treatment]][[Category:Psilactis]]