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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.

 

VISCACEAE MISTLETOE FAMILY

Job Kuijt


Perennial herb, shrub, generally ± green, parasitic on aboveground parts of woody plants; dioecious [monoecious]. Stem: brittle; 2° branches generally many. Leaf: simple, entire, opposite, 4-ranked, with blade or scale-like (then each pair generally fused). Inflorescence: spikes or cymes, axillary or terminal; bracts opposite, 4-ranked, scale-like, each pair fused. Flower: unisexual, radial, 2–4 mm; perianth parts in 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. Seed: 1(2), without thickened coat, gelatinous.
7 genera, ± 450 species: tropics, generally northern temperate. All parts of most members may be TOXIC. [Kuijt 2003 Syst Bot Monogr 66:1–643] Sometimes included in Loranthaceae; parasitic on plants in many other families. —Scientific Editor: Thomas J. Rosatti.
Unabridged references: [Kuijt 1969 Biol Parasitic Fl Plants; Kuijt 1982 J Arnold Arbor 63:401–410; Kuijt 2003 Syst Bot Monogr 66:1–643]

Key to Viscaceae

1. Stem generally < 20 cm, ± angled at least when young, straw-colored, yellow, yellow-green, olive-green, green, brown, purple; leaf scale-like, < 1 mm; fruit ± broadly fusiform-spheric, 2-colored (1 color below, 1 above), not white, not pink, not ± red, explosive, pedicel recurved; pistillate perianth parts 2; anthers ± 1-chambered; on Abies, Pinus, Pseudotsuga, Tsuga, Picea ..... ARCEUTHOBIUM

1' Stem generally > 20 cm, not angled, green, yellow-green, gray-green, less often ± red; leaf blade 5–70 mm, or leaf scale-like, < 1 mm; fruit ± spheric, 1-colored, white, pink, or ± red, not explosive, pedicel ± straight or 0; pistillate perianth parts generally 3–4; anthers 2–several-chambered; on woody angiosperms or Abies, Calocedrus, Juniperus, Hesperocyparis.

2. Perianth parts generally 3, pistillate persistent; inflorescence few- to many-flowered spikes; flowers ± sunken into axis (by proliferation of axis tissue); fruit ± 3–6 mm; leaf blade 5–47 mm, or leaf scale-like, < 1 mm, glabrous or minutely tomentose; anthers 2-chambered; on especially Abies, Acacia, Adenostoma, Alnus, Arctostaphylos, Calocedrus, Cercidium, Fraxinus, Hesperocyparis, Juglans, Juniperus, (Larrea), Olneya, Platanus, Populus, Prosopis, Quercus, Rhus, Robinia, Salix, Umbellularia, reportedly on Pinus monophylla ..... PHORADENDRON

2' Perianth parts generally 4, pistillate generally deciduous; inflorescence few-flowered cymes; flowers not sunken into axis; fruit 6–10 mm; leaf blade generally 50–80 mm, fleshy, glabrous; anthers several-chambered; on especially Acer, Alnus, Betula, Crataegus, Malus, Populus, Robinia, Salix, Ulmus ..... VISCUM

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Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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