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glandular willowherb, Hall's willowherb, Sierra willowherb

glaucous willowherb, glaucus willowherb, smooth willowherb

Habit Herbs with small, 3–6 mm, round or oblong, compact turions 1–5 cm below ground. Herbs with branching, wiry basal shoots with crowded, often dark, scales.
Stems

strict, erect, terete, 2–50(–60) cm, rarely branched only in larger plants, subglabrous proximal to inflorescence except for raised strigillose lines decurrent from margins of petioles, or sometimes ± densely long-villous throughout with inconspicuous decurrent lines.

many, erect or ascending, often densely clumped, slender, terete, 5–75(–85) cm, simple or distally branched, glabrous and glaucous, sometimes strigillose and/or mixed glandular puberulent distally, rarely with faint raised strigillose lines decurrent from margins of distal petioles.

Leaves

opposite proximally, alternate on inflorescence, subsessile or proximally with petioles 1–1.5 mm;

blade ovate proximally to lanceolate or narrowly elliptic distally, 0.5–4.7 × 0.2–1.4 cm, base rounded to cuneate, margins subentire proximally to denticulate distally, 8–20 teeth per side, veins inconspicuous, 3–6 per side, apex obtuse to subacute, surfaces mostly glabrous with strigillose margins;

bracts much reduced.

opposite and crowded proximal to inflorescence, alternate and widely spaced distally, subsessile and ± clasping;

blade light green or blue-green, very narrowly lanceolate to narrowly ovate or elliptic, (0.5–)1–7.2 × (0.3–)0.5–1.8 cm, base cuneate, margins subentire or faintly denticulate, 8–15 teeth per side, veins inconspicuous, 3–6 per side, apex obtuse proximally to acute distally, glabrous and glaucous;

bracts much reduced and narrower.

Inflorescences

usually nodding in bud, erect later, open racemes, sometimes congested, usually mixed strigillose and glandular puberulent, rarely also mixed villous, or rarely subglabrous.

erect racemes, glabrous or ± sparsely glandular puberulent, sometimes mixed strigillose.

Flowers

erect;

buds 2–5 × 1–2 mm;

pedicel 3–8 mm;

floral tube 0.5–1.7 × 0.8–1.6 mm, with slightly raised ring of spreading hairs at mouth inside;

sepals green, 1.2–2.8 × 0.5–1 mm, abaxial surface subglabrous or sparsely glandular puberulent;

petals white, often fading pink, 1.6–5.5 × 1.2–3 mm, apical notch 0.3–1.2 mm;

filaments white or cream, those of longer stamens 0.6–2.5 mm, those of shorter ones 0.4–1.5 mm;

anthers cream, 0.2–0.9 × 0.2–0.5 mm;

ovary 10–14 mm, strigillose and glandular puberulent or subglabrous;

style cream, 0.8–5 mm, stigma clavate, entire, 0.4–1.2 × 0.3–0.7 mm, usually surrounded by, rarely exserted beyond, anthers.

erect;

buds 2.5–5 × 2–3.5 mm;

pedicel 2–11(–20) mm;

floral tube 0.7–2.3 × 1–2.5 mm, ring of spreading hairs at mouth inside or without a ring;

sepals often red-tipped, sometimes keeled, 2.5–7.5 × 0.8–2 mm, abaxial surface glabrous or strigillose and/or glandular puberulent;

petals usually light pink to rose-purple, rarely white, 3.4–10(–12) × 1.8–5 mm, apical notch 0.5–3 mm;

filaments purple to white or cream, those of longer stamens 2.4–5(–6) mm, those of shorter ones 1.4–4 mm;

anthers light yellow, 0.5–1.2(–1.5) × 0.3–0.7 mm;

ovary 10–42 mm, subglabrous to sparsely mixed strigillose and glandular puberulent;

style light yellow or cream, 1.7–5(–7) mm, stigma clavate to subcapitate, 0.8–3 × 0.5–1.2 mm, usually surrounded by, rarely exserted beyond, longer anthers.

Capsules

very narrowly cylindrical, (15–)24–60 mm, surfaces usually subglabrous to mixed strigillose and glandular puberulent, rarely sparsely villous;

pedicel 8–40 mm.

15–75 mm, with small protuberance at base, surfaces subglabrous to sparsely mixed strigillose and glandular puberulent;

pedicel 5–18(–25) mm.

Seeds

narrowly fusiform to narrowly obovoid, 1.1–1.6 × 0.4–0.6 mm, chalazal collar ± conspicuous, 0.05–0.2 mm, light brown, surface papillose;

coma easily detached, white, 3–6 mm.

narrowly obovoid, 0.7–1(–1.3) × 0.3–0.5 mm, chalazal collar inconspicuous, light brown or gray, surface coarsely papillose in longitudinal rows;

coma readily detached, white, 4–9 mm.

2n

= 36.

Epilobium hallianum

Epilobium glaberrimum

Phenology Flowering Jun–Sep.
Habitat Semi-shaded stream banks, wet grassy slopes or meadows, bogs, seasonally wet sites, vernal pools.
Elevation 100–3700 m. (300–12100 ft.)
Distribution
from FNA
AZ; CA; CO; ID; MT; NM; NV; OR; SD; UT; WA; WY; AB; BC; SK
[WildflowerSearch map]
[BONAP county map]
from USDA
w North America; nw Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Epilobium hallianum has condensed fleshy turions and generally strict habit, suggesting an affinity with E. ciliatum or E. saximontanum, both with the AA arrangement. However, E. hallianum has the BB arrangement (S. R. Seavey and P. H. Raven 1978) and apparently more distant relationship to those other species.

In different parts of its geographical range Epilobium hallianum shows considerable morphological variability, especially in leaf shape and margins, and in type and pattern of stem vestiture, including plants in the southern part of its range with densely villous stems that have been treated as E. ursinum. In part because of this variability and in part because the very characteristic condensed turions are easily lost during collection and/or often overlooked, E. hallianum is frequently misidentified.

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

Subspecies 2 (2 in the flora).

Epilobium glaberrimum is restricted mainly to the Sierra Nevada-Cascade region, but also (subsp. fastigiatum) in the northern Rocky Mountains. It is one of the more easily identified species due to its consistently glabrous and glaucous aspect. Although the distributions and elevational ranges of the two subspecies appear to overlap extensively, they are largely allopatric with subsp. glaberrimum occurring in lower to mid montane zones and subsp. fastigiatum in upper montane to subalpine zones in the southern part of its range, and in lower zones farther north.

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

Key
1. Stems 20–75(–85) cm; leaf blades (2–)3–7.2 cm, very narrowly lanceolate to lanceolate or narrowly elliptic (length/width ratio more than 4); capsules 45–75 mm; petals (4–)5–10(–12) mm.
subsp. glaberrimum
1. Stems 5–35 cm; leaf blades (0.5–)1–3.4 cm, lanceolate to narrowly ovate or elliptic (length/width ratio less than 4); capsules 15–45(–55) mm; petals 3.4–8 mm.
subsp. fastigiatum
Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Epilobieae > Epilobium > sect. Epilobium Onagraceae > subfam. Onagroideae > tribe Epilobieae > Epilobium > sect. Epilobium
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. hirsutum, E. hornemannii, E. howellii, E. lactiflorum, E. leptocarpum, E. leptophyllum, E. luteum, E. minutum, E. mirabile, E. montanum, E. nevadense, E. nivium, 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
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. hallianum, E. hirsutum, E. hornemannii, E. howellii, E. lactiflorum, E. leptocarpum, E. leptophyllum, E. luteum, E. minutum, E. mirabile, E. montanum, E. nevadense, E. nivium, 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
Subordinate taxa
E. glaberrimum subsp. fastigiatum, E. glaberrimum subsp. glaberrimum
Synonyms E. brevistylum var. pringleanum, E. brevistylum var. subfalcatum, E. brevistylum var. tenue, E. brevistylum var. ursinum, E. delicatum var. tenue, E. glandulosum var. tenue, E. pringleanum, E. pringleanum var. tenue, E. ursinum, E. ursinum var. subfalcatum E. fastigiatum var. glaberrimum
Name authority Haussknecht: Monogr. Epilobium, 261. (1884) — (as halleanum) Barbey in W. H. Brewer et al.: Bot. California 1: 220. (1876)
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