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 +
brown +, orange +, yellow +, olive green +  and yellowish green +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (?) +  and 0.3 cm3 mm <br />0.003 m <br /> (?) +
scale-like +
10 cm100 mm <br />0.1 m <br /> (22 cm220 mm <br />0.22 m <br />) +
3 cm30 mm <br />0.03 m <br /> (?) +  and 10 cm100 mm <br />0.1 m <br /> (?) +
Larch dwarf mistletoe +
spikelike +
B.C. +, Idaho +, Mont. +, Oreg. +  and Wash. +
600–2300 m. +
globose +  and pyriform +
2.7 cm27 mm <br />0.027 m <br /> (?) +
lenticular +
3.5 cm35 mm <br />0.035 m <br /> (?) +
2.5 cm25 mm <br />0.025 m <br /> (?) +
Coniferous forests, especially with western larch or mountain hemlock. +
terminal +  and axillary +
bisexual +  and unisexual +
0.8 cm8 mm <br />0.008 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
connate +
scale-like +
pinnate +  and entire +
articulated +
asymmetric +  and symmetric +
yellowish green +
connate +  and distinct +
deltate +  and triangular +
Flowering Jul–Aug +  and fruiting (Aug–)Sep(–Oct). +
2[-3]-carpellate +
Phytoneuron +
mucilaginous +
0.33 cm3.3 mm <br />0.0033 m <br /> (?) +  and 0.55 cm5.5 mm <br />0.0055 m <br /> (?) +
pyriform +  and ellipsoid +
0.23 cm2.3 mm <br />0.0023 m <br /> (?) +  and 0.4 cm4 mm <br />0.004 m <br /> (?) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
3 +  and 4 +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
purple;maroon;purple;maroon;olive green;green +
pendulous +  and erect +
fanlike +
4 cm40 mm <br />0.04 m <br /> (?) +
undifferentiated +
A. laricis +  and Razoumofskya laricis +
Arceuthobium campylopodum subsp. laricis +
Arceuthobium campylopodum +
subspecies +
spikelike +
mucilaginous +
evergreen +  and perennial +