Petrophytum hendersonii

(Canby) Rydberg in N. L. Britton et al.

in N. L. Britton et al., N. Amer. Fl. 22: 253. 1908.

Common names: Olympic mountain rockmat
Endemic
Basionym: Eriogynia hendersonii Canby Bot. Gaz. 16: 236. 1891 (as hendersoni)
Synonyms: Luetkea hendersonii (Canby) Greene Spiraea hendersonii (Canby) Piper
Treatment appears in FNA Volume 9. Treatment on page 412. Mentioned on page 411, 413.
Revision as of 14:26, 30 July 2020 by imported>Volume Importer
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Shrubs, 2–9 dm diam. Stems decumbent to ascending, 1–10 cm, internodes 0.5–1.5 cm. Leaves: blade narrowly obtrullate, sometimes oblanceolate to spatulate-obovate, 1–2 (–3) × 0.2–0.6 cm, palmately 3-veined, venation visible through hairs, apex acute, abaxial surface sparsely strigose, pilose to pilose-sericeous, sometimes glabrate, sparsely strigose along veins. Panicles densely racemose, 2–5 × 1–2 cm, sparsely sericeous; bracts linear, 2–4 (–6) mm, pilose. Pedicels 2–5 mm; bracteoles 1, rarely extending to base of sepals. Flowers 3–5 mm diam.; hypanthium 0.5–1 mm, sparsely pilose; sepals reflexed, oblong to obtuse, 1–1.5 mm, margins ciliate, abaxial surface sparsely pilose; petals oval, oblong, or obovate, 2–2.5 mm, apex obtuse, sometimes 2-lobate; stamens 25–40, lengths 1–1.3 times petals (2 times sepals); carpels (4–) 5 (–6), abaxially connate. Follicles 1.5–2 mm. 2n = 18.


Phenology: Flowering Jul–Sep.
Habitat: Rock outcrops, cliffs, talus slopes
Elevation: 1000–2300 m

Discussion

Petrophytum hendersonii is known only from the Olympic Mountains of northwestern Washington.

Selected References

None.

Lower Taxa

None.

"dm" is not declared as a valid unit of measurement for this property.

... more about "Petrophytum hendersonii"
pilose +, strigose +, glabrate +  and pilose-sericeous +
2-lobate;obtuse;acute +
Richard Lis +
(Canby) Rydberg in N. L. Britton et al. +
gray +, brown +  and dark-brown +
compound +  and simple +
opposite +  and alternate +
Eriogynia hendersonii +
2 cm20 mm <br />0.02 m <br /> (3 cm30 mm <br />0.03 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (3 cm30 mm <br />0.03 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
oblanceolate +  and spatulate-obovate +
0.2 cm2 mm <br />0.002 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
coriaceous +
0.2 cm2 mm <br />0.002 m <br /> (?) +  and 0.6 cm6 mm <br />0.006 m <br /> (?) +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (?) +  and 0.4 cm4 mm <br />0.004 m <br /> (?) +
hirsute +  and pilose +
Olympic mountain rockmat +
not +  and aggregated +
1000–2300 m +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
canescent +  and sericeous +
unisexual +  and bisexual +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
pilose +, glabrate +  and glabrous +
lanceoloid +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
coriaceous +
not +  and aggregated +
not +  and aggregated +
Rock outcrops, cliffs, talus slopes +
turbinate +  and hemispheric +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
crassinucellate +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
compound +  and simple +
marcescent +
persistent +
entire +  and crenulate +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and apical +
3 +  and 2 +
2cm +  and 5cm +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0 (?) +  and 4 (?) +
persistent +
free +  and distinct +
obovate;oblong;obovate;oblong;oval +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Flowering Jul–Sep. +
adnate +, free +, connate +  and distinct +
in N. L. Britton et al., N. Amer. Fl. +
not arillate +
list;count +
persistent +
free +  and distinct +
oblong +  and obtuse +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
free +  and distinct +
1-1.3 times petals +
branched +  and simple +
decumbent +  and ascending +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
persistent +  and deciduous +
distinct +
basal +, lateral +, subterminal +  and terminal +
not elongate +
sericeous +, pilose +, canescent +, strigose +  and glabrate +
Luetkea hendersonii +  and Spiraea hendersonii +
Petrophytum hendersonii +
Petrophytum +
species +
inconspicuous +
thickened +  and minute +