Epilobium septentrionale

(D. D. Keck) R. N. Bowman & Hoch

Ann. Missouri Bot. Gard. 66: 897. 1980.

Common names: Northern willowherb
Basionym: Zauschneria septentrionalisd. D. Keck Publ. Carnegie Inst. Wash. 520: 219, figs. 84 [top center], 85 [upper right]. 1940
Synonyms: Epilobium canum subsp. septentrionale (D. D. Keck) P. H. Raven
Treatment appears in FNA Volume 10.

Herbs usually not suffruticose, with basal shoots from thick­ened caudex, often decussate scales at base. Stems decumbent, often matted, grayish green, terete, 5–25 cm, well-branched throughout, densely white-canescent proximally, mixed strigillose, villous, and glandular puberulent distally. Leaves densely spaced, opposite proximal to inflorescence, alternate or fasciculate distally, petiole 0–2 mm, blade grayish green to green, lanceolate or elliptic to narrowly ovate, 1–3.5 (–4) × 0.4–1.1 cm, base cuneate or attenuate, margins sub­entire to low-denticulate, 5–8 teeth per side, veins inconspicuous, 3–5 per side, apex acute, sometimes with caducous dark mucro, surfaces densely white-canescent and eglandular proximally, changing abruptly on inflorescence to glandular puberulent mixed with scattered villous; bracts somewhat reduced. Inflorescences ascending spikes or racemes, densely glandular puberulent. Flowers: buds 12–15 × 4–5.5 mm, subsessile or pedicels 1–2 mm; floral-tube same color as petals, 17–23 × 3.5–5 mm, with ring of scales 4–5 mm from base inside; sepals same color as petals, 7–12 × 2.5–3.5 mm; petals red-orange, 8–14 × 5–6.5 mm, apical notch 1.8–2.4 mm; filaments orange or red, those of longer stamens 15–17 mm, those of shorter ones 13–15 mm; anthers 2.8–3.2 × 0.7–1 mm; ovary 5–11 mm, glandular puberulent; style light orange, 40–45 mm, stigma 4-lobed, 0.9–1.1 × 2.2–2.6 mm, exserted 8–10 mm beyond anthers. Capsules ± straight, 20–26 mm, ± beaked, surfaces glandular puberulent; sessile or pedicel 1–3 mm. Seeds broadly to narrowly obovoid, with constriction 0.7–0.8 mm from micropylar end, 1.8–2.4 × 1.1–1.3 mm, chalazal collar inconspicuous, light-brown, surface low-papillose; coma easily detached, dingy white, 6–7 mm. 2n = 30.


Phenology: Flowering Aug–Sep.
Habitat: Rocky ledges and serpentine slopes along rivers.
Elevation: 10–1900 m.

Discussion

Epilobium septentrionale is endemic to northern California, found only in the drainages of the Eel, Mattole, and Trinity rivers in Humboldt, Mendocino, and Trinity counties. The dimorphic pattern of vestiture on this species (eglandular, white-canescent lower leaves versus glandular puberulent upper leaves and bracts) is highly distinctive and not found in any specimens of E. canum. Most collections are relatively uniform in aspect, leaves, flowers, fruits, and seeds, despite the relative isolation from one another in the different river drainages where they occur.

S. R. Seavey and P. H. Raven (1977c) reported an experimental hybrid between Epilobium septentrionale and diploid E. canum subsp. canum; although it had normal chromosome pairing, pollen fertility was reduced (51%).

Selected References

None.

Lower Taxa

None.
... more about "Epilobium septentrionale"
0.28 cm2.8 mm <br />0.0028 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
episepalous +
subequal +  and longer +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
Peter C. Hoch +
(D. D. Keck) R. N. Bowman & Hoch +
attenuate +  and cuneate +
Zauschneria septentrionalisd. +
indehiscent +  and loculicidal +
3.5 cm35 mm <br />0.035 m <br /> (4 cm40 mm <br />0.04 m <br />) +
grayish green +  and green +
1 cm10 mm <br />0.01 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
toothed +  and entire +
elliptic +  and narrowly ovate +
0.4 cm4 mm <br />0.004 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
reduced +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
recurved +  and erect +
0.4 cm4 mm <br />0.004 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
sessile +  and pedicellate +
subclavate +  and fusiform +
2 cm20 mm <br />0.02 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
subsessile +  and short-pedicellate +
dingy white +
persistent +
detached +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Northern willowherb +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
10–1900 m. +
red +  and orange +
basifixed +  and versatile +
1.3 cm13 mm <br />0.013 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1.7 cm17 mm <br />0.017 m <br /> (2.3 cm23 mm <br />0.023 m <br />) +
3.5mm +  and 5mm +
suberect +  and spread +
sessile +  and pedicellate +
curved +  and straight +
4-angled +, terete +, narrowly cylindrical +  and fusiform or rarely narrowly ellipsoidal +
slender +
Rocky ledges and serpentine slopes along rivers. +
perennial +
suffruticose +
fasciculate +, alternate +, opposite +  and spaced +
deciduous +
decurrent +
0.5 cm5 mm <br />0.005 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
numerous +  and 1 +
multicellular +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
8mm +  and 14mm +
obovate +  and obcordate +
0.5 cm5 mm <br />0.005 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
0 cm0 mm <br />0 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Flowering Aug–Sep. +
Ann. Missouri Bot. Gard. +
inflated +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
basal +  and cauline +
clavate +  and globose +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
sculptured +  and smooth +
obovoid +
constricted +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
lanceolate +, , +, flushed with red or flushed with cream +  and green +
deciduous +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
parenchymatous +
parietal +, axile +  and placentation +
unequal +
aquatic +, amphibious +  and terrestrial +
2 times as many as sepals +
well-branched +
grayish green +
erect +  and ascending or decumbent +
puberulent +, villous +, strigillose +  and white-canescent +
exfoliating +
5 cm50 mm <br />0.05 m <br /> (25 cm250 mm <br />0.25 m <br />) +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
subsessile +  and petiolate +
intrapetiolar +
light orange +
4 cm40 mm <br />0.04 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
aquatic +, amphibious +  and terrestrial +
sessile +  and eglandular +
puberulent +  and white-canescent +
low-papillose +
constricted +
Epilobium canum subsp. septentrionale +
Epilobium septentrionale +
Epilobium sect. Zauschneria +
species +
3(-5)-aperturate +
entire +  and low-denticulate +
inconspicuous +