Arceuthobium campylopodum subsp. laricis

(M. E. Jones) Nickrent
Phytoneuron 2012-51: 9. 2012.
Common names: Larch dwarf mistletoe
Endemic
Basionym: Arceuthobium douglasii var. laricis M. E. Jones Biol. Ser. Bull. State Univ. Montana. 15: 25. 1910
Synonyms: A. laricis (M. E. Jones) H. St. John Razoumofskya laricis (M. E. Jones) Piper
Treatment appears in FNA Volume 12. Treatment on page 432. Mentioned on page 429.

Plants forming witches' brooms. Stems green, olive green, maroon, or purple, 4(–6) cm; third internode 5–8(–14) × 1–1.3(–2.5) mm, dominant shoot 1.5–3 mm diam. at base. Staminate flowers 2.7 mm diam.; petals 3(–4). Fruits 3.5 × 2.5 mm.


Phenology: Flowering Jul–Aug; fruiting (Aug–)Sep(–Oct).
Habitat: Coniferous forests, especially with western larch or mountain hemlock.
Elevation: 600–2300 m.

Distribution

V12 156-distribution-map.jpg

B.C., Idaho, Mont., Oreg., Wash.

Discussion

Meiosis occurs in June, with fruits maturing 13–14 months after pollination.

Larix occidentalis and Tsuga mertensiana are the principal hosts for subsp. laricis; secondary to rare hosts include Abies grandis, A. lasiocarpa, Picea engelmannii, Pinus albicaulis, P. contorta, P. monticola, and P. ponderosa. This dwarf mistletoe is a major pathogen on larch in Idaho and Montana.

Selected References

None.

Lower Taxa

None.

Daniel L. Nickrent +
(M. E. Jones) Nickrent +
Arceuthobium douglasii var. laricis +
Larch dwarf mistletoe +
B.C. +, Idaho +, Mont. +, Oreg. +  and Wash. +
600–2300 m. +
Coniferous forests, especially with western larch or mountain hemlock. +
Flowering Jul–Aug +  and fruiting (Aug–)Sep(–Oct). +
Phytoneuron +
A. laricis +  and Razoumofskya laricis +
Arceuthobium campylopodum subsp. laricis +
Arceuthobium campylopodum +
subspecies +