LYTHRACEAE

LOOSESTRIFE FAMILY

Elizabeth McClintock

Annual, perennial herb, shrubs, trees
Stem angled or cylindric
Leaves simple, entire, generally opposite, sometimes alternate or whorled
Inflorescence: raceme, spike, or panicle, terminal, or axillary clusters with 1–several flowers
Flower bisexual, generally radial; hypanthium cylindric to bell-shaped, generally membranous, persistent in fruit; sepals 4–6, generally persistent, appendages 3–5 or 0, alternate sepals; petals, stamens inserted on inner hypanthium; petals 4–6 or 0, alternate sepals, deciduous; stamens generally = or 2 X petals, included or exserted; ovary superior, chambers 2–6, style generally slender, stigma head-like
Fruit: capsule, opening by valves from top, splitting sometimes irregular or 0
Seeds 3–many
Genera in family: ± 25 genera, 450 species: temp, tropical, generally in wet habitats. Some ornamental or cultivated for medicine, dyes
Reference: [Graham 1964 J Arnold Arbor 45:235–250]

LYTHRUM

Annual, perennial herb
Stem prostrate to erect, sometimes 4-angled
Leaves opposite, alternate, or whorled, linear to ovate, sessile or short-petioled
Inflorescence: raceme- or spike-like; flowers generally 1–2 per axil; bracts 2 per node
Flower radial to slightly bilateral, sometimes of 2–3 forms (heterostyly); hypanthium cylindric to bell-shaped; sepals 4–6, appendages < to > sepals; petals 4–6 or 0; stamens 4–6 or 12, included or exserted; styles < to > stamens
Fruit generally cylindric, generally dehiscent by 2 valves
Seeds many, < 1 mm
Species in genus: ± 35 species: temp
Etymology: (Greek: blood, from flower color)
Reference: [Stuckey 1980 Bartonia 47:3–20]

Native

L. californicum Torr. & A. Gray

CALIFORNIA LOOSESTRIFE

Perennial, heterostylous
Stem erect, 2–6 dm, generally branching above; branches spreading to ascending, glabrous
Leaves: lower opposite; upper alternate, 1–7 cm, linear to linear-lanceolate, ± glaucous
Inflorescence terminal, ± spike-like; bracts generally linear; pedicels 1–2 mm
Flowers of 2 style forms; hypanthium cylindric, 4–7 mm; sepals narrowly deltate, < 1 mm, ± = appendages; petals 4–8 mm, purple; stamens generally 6, included; style included or exserted
Fruit ovoid, ± = hypanthium
Chromosomes: 2n=20
Ecology: Marshes, pond and stream margins
Elevation: < 2200 m.
Bioregional distribution: s Inner North Coast Ranges, Sierra Nevada Foothills, s High Sierra Nevada, Great Central Valley, Central Western California, Southwestern California, White and Inyo Mountains, Desert
Distribution outside California: to c US, n Mexico
Flowering time: Apr–Sep
Horticultural information: INV; STBL.