FNA: Epilobium nivium

	Epilobium nivium
	Snow Mountain willowherb
Habit	Herbs with many shoots from thick, woody caudex 5–12 mm diam..
Stems	erect or ascending, terete, 10–25 cm, sparsely branched distally, densely grayish white-strigillose.
Leaves	subsessile or petioles 0.5–2.5 mm, blade elliptic or narrowly so to lanceolate, often folded along midrib, 0.9–1.8 × 0.3–0.7 cm, usually longer than internodes, base rounded to cuneate, margins subentire or low denticulate, 1–3 low teeth per side, lateral veins inconspicuous, 1–3 per side, apex blunt to acute with conspicuous dark brown mucronate tip, surfaces densely spreading-hairy; bracts very reduced, attached to pedicel 1–2 mm from base.
Inflorescences	erect open racemes or panicles, densely spreading-hairy.
Flowers	erect; buds 6–8 × 2.5–3.2 mm; floral tube 5.2–9.5 × 2.4–3.2 mm, constriction 4–6 mm distal to base, base ± bulbous, spreading-hairy from mouth nearly to base inside; sepals 2.7–4.2 × 1.6–2 mm, abaxial surface densely villous and glandular puberulent; petals rose-purple, 6–9.5 ×3.8–6.2 mm, apical notch 1.5–2.5 mm; filaments light pink, those of longer stamens 5–6.5 mm, those of shorter ones 3–3.5 mm; anthers 1.3–2.1 × 0.6–0.9 mm, apiculate; ovary 2.5–4.5 mm, densely villous and glandular puberulent; style pinkish cream, 11–17 mm, glabrous, stigma 4-lobed, 0.8–1 × 1.1–2.1 mm, lobes often not spread and then cuplike, usually exserted beyond anthers.
Capsules	fusiform, 8–16 mm, surfaces glandular puberulent; pedicel 2–5 mm.
Seeds	obovoid to broadly so, with slight constriction 0.4–0.6 mm from micropylar end, 1.5–2.4 × 0.8–1.3 mm, inconspicuous chalazal collar, dark brown, surface papillose; coma easily detached, dingy white, 6.5–7.5 mm.
2n	= 30.

	Epilobium nivium
Phenology	Flowering late Jul–Sep.
Habitat	Crevices in rocky outcrops, shale or talus slopes, with scrub oak (Quercus), Abies concolor, and Pinus jeffreyi.
Elevation	1600–2400 m. (5200–7900 ft.)
Distribution	CA [BONAP county map]
Discussion	Epilobium nivium has an extremely restricted range, mainly in the Snow Mountain region of Colusa and Lake counties, but recent collections from Mendocino and southern Trinity counties have extended its range several hundred km to the north. Many collections, notably including the type gathering, have strikingly woody bases, suggesting that these are long-lived plants. Like E. nevadense and some other species in the genus that characteristically grow on scree slopes, the lower part of the stems often lack leaves, which may be abraded by movement of the rocky substrate. As reported by S. R. Seavey and P. H. Raven (1977c) and also noted on some herbarium labels, capsules of Epilobium nivium sometimes show signs of possible seed predation by moth larvae as reported for E. nevadense. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 10.
Parent taxa	Onagraceae > subfam. Onagroideae > tribe Epilobieae > Epilobium > sect. Cordylophorum > subsect. Petrolobium
Sibling taxa	E. anagallidifolium, E. arcticum, E. brachycarpum, E. campestre, E. canum, E. ciliatum, E. clavatum, E. cleistogamum, E. coloratum, E. davuricum, E. densiflorum, E. densum, E. foliosum, E. glaberrimum, E. hallianum, E. hirsutum, E. hornemannii, E. howellii, E. lactiflorum, E. leptocarpum, E. leptophyllum, E. luteum, E. minutum, E. mirabile, E. montanum, E. nevadense, E. obcordatum, E. obscurum, E. oreganum, E. oregonense, E. pallidum, E. palustre, E. parviflorum, E. rigidum, E. saximontanum, E. septentrionale, E. siskiyouense, E. smithii, E. suffruticosum, E. torreyi
Name authority	Brandegee: Zoë 3: 242, plate 24. (1892)
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Epilobium nivium

Snow Mountain willowherb

Habit

Herbs with many shoots from thick, woody caudex 5–12 mm diam..

Stems

erect or ascending, terete, 10–25 cm, sparsely branched distally, densely grayish white-strigillose.

Leaves

subsessile or petioles 0.5–2.5 mm, blade elliptic or narrowly so to lanceolate, often folded along midrib, 0.9–1.8 × 0.3–0.7 cm, usually longer than internodes, base rounded to cuneate, margins subentire or low denticulate, 1–3 low teeth per side, lateral veins inconspicuous, 1–3 per side, apex blunt to acute with conspicuous dark brown mucronate tip, surfaces densely spreading-hairy;

bracts very reduced, attached to pedicel 1–2 mm from base.

Inflorescences

erect open racemes or panicles, densely spreading-hairy.

Flowers

erect;

buds 6–8 × 2.5–3.2 mm;

floral tube 5.2–9.5 × 2.4–3.2 mm, constriction 4–6 mm distal to base, base ± bulbous, spreading-hairy from mouth nearly to base inside;

sepals 2.7–4.2 × 1.6–2 mm, abaxial surface densely villous and glandular puberulent;

petals rose-purple, 6–9.5 ×3.8–6.2 mm, apical notch 1.5–2.5 mm;

filaments light pink, those of longer stamens 5–6.5 mm, those of shorter ones 3–3.5 mm;

anthers 1.3–2.1 × 0.6–0.9 mm, apiculate;

ovary 2.5–4.5 mm, densely villous and glandular puberulent;

style pinkish cream, 11–17 mm, glabrous, stigma 4-lobed, 0.8–1 × 1.1–2.1 mm, lobes often not spread and then cuplike, usually exserted beyond anthers.

Capsules

fusiform, 8–16 mm, surfaces glandular puberulent;

pedicel 2–5 mm.

Seeds

obovoid to broadly so, with slight constriction 0.4–0.6 mm from micropylar end, 1.5–2.4 × 0.8–1.3 mm, inconspicuous chalazal collar, dark brown, surface papillose;

coma easily detached, dingy white, 6.5–7.5 mm.

= 30.

Epilobium nivium

Phenology

Flowering late Jul–Sep.

Habitat

Crevices in rocky outcrops, shale or talus slopes, with scrub oak (Quercus), Abies concolor, and Pinus jeffreyi.

Elevation

1600–2400 m. (5200–7900 ft.)

Distribution

[BONAP county map]

Discussion

Epilobium nivium has an extremely restricted range, mainly in the Snow Mountain region of Colusa and Lake counties, but recent collections from Mendocino and southern Trinity counties have extended its range several hundred km to the north. Many collections, notably including the type gathering, have strikingly woody bases, suggesting that these are long-lived plants. Like E. nevadense and some other species in the genus that characteristically grow on scree slopes, the lower part of the stems often lack leaves, which may be abraded by movement of the rocky substrate.

As reported by S. R. Seavey and P. H. Raven (1977c) and also noted on some herbarium labels, capsules of Epilobium nivium sometimes show signs of possible seed predation by moth larvae as reported for E. nevadense.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source

FNA vol. 10.

Parent taxa

Onagraceae > subfam. Onagroideae > tribe Epilobieae > Epilobium > sect. Cordylophorum > subsect. Petrolobium

Sibling taxa

E. anagallidifolium, E. arcticum, E. brachycarpum, E. campestre, E. canum, E. ciliatum, E. clavatum, E. cleistogamum, E. coloratum, E. davuricum, E. densiflorum, E. densum, E. foliosum, E. glaberrimum, E. hallianum, E. hirsutum, E. hornemannii, E. howellii, E. lactiflorum, E. leptocarpum, E. leptophyllum, E. luteum, E. minutum, E. mirabile, E. montanum, E. nevadense, E. obcordatum, E. obscurum, E. oreganum, E. oregonense, E. pallidum, E. palustre, E. parviflorum, E. rigidum, E. saximontanum, E. septentrionale, E. siskiyouense, E. smithii, E. suffruticosum, E. torreyi

Name authority

Brandegee: Zoë 3: 242, plate 24. (1892)

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

Choose a data source: Flora of North America

The species comparison tool is brought to you by:

Flora of North America species comparison

Epilobium nivium

Epilobium nivium