Phoradendron villosum

(Nuttall) Nuttall ex Engelmann

Boston J. Nat. Hist. 6: 212. 1850.

Common names: Pacific or oak mistletoe
Basionym: Viscum villosum Nuttall in J. Torrey and A. Gray Fl. N. Amer. 1: 654. 1840
Synonyms: Phoradendron flavens var. villosum (Nuttall) Engelmann
Treatment appears in FNA Volume 12. Treatment on page 438. Mentioned on page 435, 439.

Subshrubs, erect, to 1 dm diam., dioecious. Stems green or olive green, grayish from pubescence, hairy, hairs stellate, becoming hirtellous to glabrate; internodes terete, 1.5–3.8 × 1–3 mm. Leaves green or olive green, grayish from pubescence, stellate-hairy; blade obovate-elliptic to orbiculate, 13–45 × 9–22 mm, thin to thick and fleshy, base subtruncate to acute, apex rounded to acute; basal phyllotaxy transverse. Staminate inflorescences 10–80 mm, stellate-hairy; peduncle with 1 internode, 2–4 mm; fertile internodes 2–5, each (14–) 26 (–44) -flowered, triseriate, becoming irregular, flowers 2–7 per column. Pistillate inflorescences 10–80 mm, stellate-hairy; peduncle with 1 internode, 2–4 mm; fertile internodes 2–3, each (6–) 11 (–24) -flowered, triseriate, flowers 1–4 per column. Flowers: petals 3–4, 1 mm. Berries white to pink, oblong to globose, 3 × 3 mm, puberulent below petals.

Distribution

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Ariz., Calif., N.Mex., Oreg., Tex., w, sw, sc United States, n Mexico

Discussion

Subspecies 3 (2 in the flora).

Phoradendron villosum was treated by J. Kuijt (2003) as a synonym of P. serotinum subsp. tomentosum (= P. leucarpum in this treatment), but P. villosum has a different, non-overlapping flowering time, shorter stem internodes, and hairy berries. In addition, P. villosum averages fewer pistillate inflorescence fertile internodes than P. leucarpum. Molecular studies by V. E. T. M. Ashworth (2000, 2000b) showed that P. villosum did not form part of the strongly supported P. leucarpum clade. For these reasons, they are here considered distinct species, as was done by D. Wiens (1964).

Subspecies flavum (I. M. Johnston) Wiens, distinguished by its yellow leaf hairs, is found in Coahuila and Durango, Mexico.

Selected References

None.

Key

1 Hairs on young stems, leaf blades, and inflorescences of one type, uniformly distributed and of similar lengths; pistillate inflorescence internodes each (7–)12(–24)-flowered; California, Oregon. Phoradendron villosum subsp. villosum
1 Hairs on young stems, leaf blades, and inflorescences of two types, some in dense clusters, relatively longer, others uniformly distributed, relatively shorter; pistillate inflorescence internodes each (6–)8(–12)-flowered; Arizona, New Mexico, Texas. Phoradendron villosum subsp. coryae

"thin" is not a number."dm" is not declared as a valid unit of measurement for this property.

... more about "Phoradendron villosum"
rounded +  and acute +
Daniel L. Nickrent +
- Nuttall Nuttall ex Engelmann +
subtruncate;acute +
Viscum villosum +
white +  and pink +
3 cm30 mm <br />0.03 m <br /> - ? +
oblong;globose +
3 cm30 mm <br />0.03 m <br /> - ? +
1.3 cm13 mm <br />0.013 m <br /> - 4.5 cm45 mm <br />0.045 m <br /> +
obovate-elliptic +  and orbiculate +
Pacific or oak mistletoe +
spikelike +
Ariz. +, Calif. +, N.Mex. +, Oreg. +, Tex. +, w +, sw +, sc United States +  and n Mexico +
elliptical +, ovate +  and flattened +
pistillate +  and staminate +
asymmetric +  and symmetric +
1 +  and 4 +
hirtellous +  and glabrate +
pistillate +  and staminate +
terminal +  and axillary +
1 cm10 mm <br />0.01 m <br /> - 8 cm80 mm <br />0.08 m <br /> +
- 6-11 - -24-flowered +  and  - 14-26 - -44-flowered +
1.5mm;3.8mm +
0.1 cm1 mm <br />0.001 m <br /> - 0.3 cm3 mm <br />0.003 m <br /> +
olive green;green +
stellate-hairy +  and grayish +
scale-like +
pinnate +  and entire +
articulated +
0.2 cm2 mm <br />0.002 m <br /> - ? +  and 0.4 cm4 mm <br />0.004 m <br /> - ? +
distinct +
triangular +
1 cm10 mm <br />0.01 m <br /> - 0.3 cm3 mm <br />0.003 m <br /> +
2[-3]-carpellate +
Boston J. Nat. Hist. +
mucilaginous +
percurrent +  and branching +
olive green;green +
pendulous +  and erect +
hairy +  and grayish +
multiple +  and single +
undifferentiated +
2[-3]-lobed +
Phoradendron flavens var. villosum +
Phoradendron villosum +
Phoradendron +
species +
spikelike +
mucilaginous +