Arceuthobium campylopodum subsp. tsugense

(Rosendahl) Nickrent

Phytoneuron 2012-51: 10. 2012.

Common names: Hemlock dwarf mistletoe
Endemic
Basionym: Razoumofskya tsugensis Rosendahl Minnesota Bot. Stud. 3: 272, plates 27, 28. 1903
Synonyms: Arceuthobium tsugense (Rosendahl) G. N. Jones A. tsugense subsp. amabilae Mathiasen & C. M. Daugherty A. tsugense subsp. contortae Wass & Mathiasen A. tsugense subsp. mertensianae Hawksworth & Nickrent
Treatment appears in FNA Volume 12. Treatment on page 433. Mentioned on page 429.
Revision as of 17:14, 29 July 2020 by imported>Volume Importer
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Stems yellow, green, olive green, or purple, 5–7 (–13) cm; third internode 4–9.2 (–16) × 1–1.5 (–2) mm, dominant shoot 1.5–4 mm diam. at base. Staminate flowers 2.8 mm diam.; petals 3 or 4. Fruits 3 × 3 mm.


Phenology: Flowering Jul–Sep(–Oct); fruiting (Aug–)Sep–Nov.
Habitat: Coniferous forests.
Elevation: 0–2500 m.

Distribution

V12 1060-distribution-map.jpg

B.C., Alaska, Calif., Idaho, Oreg., Wash.

Discussion

Meiosis occurs in July, with fruits maturing 12 to 13 months after pollination.

Subspecies tsugense has the broadest host range among all subspecies of Arceuthobium campylopodum. F. G. Hawksworth and D. Wiens (1996) considered subsp. tsugense to be a distinct species with two subspecies, subspp. tsugense and mertensianae. Two additional subspecies have been named: subsp. amabilae and subsp. contortae. Although the authors of these subspecies presented evidence of quantitative character variation and differences in phenology and host preferences, all variants are here considered host races of subsp. tsugense (and could be treated taxonomically as forms if so desired). The principal hosts of subsp. tsugense are Abies amabilis, A. lasiocarpa, A. procera, Pinus contorta, Tsuga heterophylla, and T. mertensiana. Secondary to rare hosts include Abies grandis, Picea breweriana, Picea engelmannii, Picea sitchensis, Pinus albicaulis, Pinus monticola, and Pseudotsuga mertensiana.

Selected References

None.

Lower Taxa

None.
Daniel L. Nickrent +
(Rosendahl) Nickrent +
Razoumofskya tsugensis +
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 /> (?) +
Hemlock dwarf mistletoe +
spikelike +
B.C. +, Alaska +, Calif. +, Idaho +, Oreg. +  and Wash. +
0–2500 m. +
globose +  and pyriform +
2.8 cm28 mm <br />0.028 m <br /> (?) +
lenticular +
3 cm30 mm <br />0.03 m <br /> (?) +
3 cm30 mm <br />0.03 m <br /> (?) +
Coniferous forests. +
terminal +  and axillary +
bisexual +  and unisexual +
0.92 cm9.2 mm <br />0.0092 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
connate +
scale-like +
pinnate +  and entire +
articulated +
asymmetric +  and symmetric +
yellowish green +
connate +  and distinct +
deltate +  and triangular +
Flowering Jul–Sep(–Oct) +  and fruiting (Aug–)Sep–Nov. +
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 /> (0.4 cm4 mm <br />0.004 m <br />) +
3 +  and 4 +
7 cm70 mm <br />0.07 m <br /> (13 cm130 mm <br />0.13 m <br />) +
purple;olive green;purple;olive green;green;yellow +
pendulous +  and erect +
fanlike +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
undifferentiated +
Arceuthobium tsugense +, A. tsugense subsp. amabilae +, A. tsugense subsp. contortae +  and A. tsugense subsp. mertensianae +
Arceuthobium campylopodum subsp. tsugense +
Arceuthobium campylopodum +
subspecies +
spikelike +
mucilaginous +
evergreen +  and perennial +