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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



Frank G. Hawksworth and Delbert Wiens

Perennial, shrub, generally ± green, parasitic on aboveground parts of woody plants, dioecious or monoecious
Stem brittle; 2° branches generally many
Leaves simple, entire, opposite, 4-ranked, with blade or leaves scale-like (then each pair generally fused)
Inflorescence: spikes or open cymes, generally axillary, sometimes terminal; bracts opposite, 4-ranked, scale-like, each pair fused
Flower unisexual, radial, 2–4 mm; perianth parts in generally ± 1 series
Staminate flower: perianth parts 3–4(7); anthers generally ± sessile, opposite and generally on perianth parts
Pistillate flower: perianth parts generally 2–4; ovary inferior, 1-chambered, style unbranched, stigma ± obscure
Fruit: berry, shiny, gelatinous
Seeds 1(–2), without thickened coat
Genera in family: 7 genera, ± 450 species: tropical, generally n temp
Reference: [Kuijt 1982 J Arnold Arbor 63:401–410]
Sometimes included in Loranthaceae; parasitic on plants in many other families. Frs generally dispersed by birds or seeds explosively ejected. All parts of most members may be TOXIC.



Perennial, shrub, glabrous, dioecious
Stem generally < 20 cm, ± angled, at least when young, yellow, straw, yellow-green, olive-green, green, brown, reddish, purple; 2° branches generally not whorled, generally in ± 1 plane
Leaf scale-like
Inflorescence: spikes, many-flowered, open or ± interrupted, short-peduncled; flowers generally opposite, 4-ranked, less often whorled
Staminate flower: perianth parts 3–4(7); anthers ± 1-chambered
Pistillate flower: perianth parts 2, persistent
Fruit generally 2–5 mm, ± compressed-spheric, 2-colored (1 color below, 1 above), dispersed by explosion, seeds projected < 15 m; pedicel short, recurved
Species in genus: ± 45 species: temp and tropical n hemisphere
Etymology: (Greek: juniper, life)
Most important timber pathogens, causing annual loss of many millions of dollars; most species cause abnormal branching (witches' brooms) in hosts
Reference: [Hawksworth & Wiens 1972 USDA Handbook No. 401]


A. americanum Engelm.


Stem 6–18(25) cm, 1–2 mm wide at base; staminate yellow, pistillate green; 2° branches whorled, in > 1 plane
Seed mature Aug–Sep
Chromosomes: n=14
Ecology: Lodgepole-pine forests, on Pinus contorta subsp. murrayana , rarely associated pines
Elevation: 1300–2500 m.
Bioregional distribution: High Cascade Range, High Sierra Nevada
Distribution outside California: to British Columbia, Colorado
Flowering time: Apr–May

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