ASTERACEAE

SUNFLOWER FAMILY

David J. Keil, Family Editor and author, except as specified

Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1–many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1–many per head
Flowers bisexual, unisexual, or sterile, ± small, of several types; calyx 0 or modified into pappus of bristles, scales, or awns, which is generally persistent in fruit; corolla radial or bilateral (rarely 0), lobes generally (0)4–5; stamens 4–5, anthers generally fused into cylinder around style, often appendaged at tips, bases, or both, filaments generally free, generally attached to corolla near throat; pistil 1, ovary inferior, 1-chambered, 1-seeded, style 1, branches 2, generally hair-tufted at tip, stigmas 2, generally on inside of style branches
Fruit: achene, cylindric to ovoid, generally deciduous with pappus attached
Genera in family: ± 1300 genera, 21,000 species (largest family of dicots): worldwide. Largest family in CA. Also see tribal key to CA genera: Strother 1997 Madroño 44(1):1–28. See glossary p. 25 for illustrations of general family characteristics.

IVA

WORMWOOD

Willard W. Payne

Annual to shrub
Leaves generally opposite below, ± alternate above
Inflorescence: heads many, disciform; involucre cup-shaped, shallow; phyllaries few, free or fused; receptacle chaffy
Pistillate flowers 0–6; corolla 0 or cylindric
Staminate flowers 5–20; corolla translucent; anthers free, yellow; style tip truncate or tack-shaped
Fruit obovate, ± compressed; pappus 0
Etymology: (Latin: from mint Ajuga iva , with similar aroma)
Reference: [Jackson 1960 Univ KS Sci Bull 41:793–876]

Native

I. hayesiana A. Gray

SAN DIEGO MARSH-ELDER

Perennial or subshrub < 1 m
Stems ± brown
Leaves 3–6 cm, ± oblanceolate, fleshy, entire, 3-veined from base, ± gland-dotted, generally short-appressed-hairy, reduced upward
Inflorescence raceme-like; heads short-peduncled, nodding; involucre 5–6 mm; phyllaries free, (ob)ovate; chaff scales linear
Pistillate flowers: corolla 0
Fruit plump, glabrous
Ecology: Alkaline flats
Elevation: < 500 m.
Bioregional distribution: s South Coast (sw San Diego Co.)
Distribution outside California: Baja California
Horticultural information: In cultivation.