Juniperus horizontalis

Moench

Methodus 699. 1794.

Common names: Creeping juniper savinier genévrier horizontal
Endemic
Synonyms: Juniperus horizontalis var. douglasii hort. Juniperus horizontalis var. variegata Beissner
Treatment appears in FNA Volume 2.

Shrubs dioecious, prostrate to decumbent; crown depressed. Bark brown, exfoliating in thin strips, that of small branchlets (5–10 mm diam.) smooth, that of larger branchlets exfoliating in wide strips or plates. Branches creeping; branchlets erect, 3–4-sided in cross-section, ca. 2/3 or less as wide as length of scalelike leaves. Leaves green but turning reddish purple in winter, abaxial gland elliptic, conspicuous, exudate absent, margins entire (at 20× and 40×); whip leaves 4–8 mm, not glaucous adaxially; scalelike leaves 1.5–2 mm, mostly overlapping to 1/3 their length, apex rounded or obtuse to acute and apiculate, spreading. Seed-cones mostly maturing in 2 years, of 2 distinct sizes, generally with curved peduncles, globose to ovoid, 5–7 mm, blue-black to brownish blue when mature, lightly glaucous, soft and resinous, with 1–2 (–3) seeds. Seeds 4–5 mm. 2n = 22.


Habitat: Sand dunes, sandy and gravelly soils, prairies, slopes, rock outcrops, and stream banks
Elevation: 0–1000 m

Distribution

V2 645-distribution-map.gif

St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Alaska, Ill., Iowa, Maine, Mass., Mich., Minn., Mont., Nebr., N.H., N.Y., N.Dak., S.Dak., Vt., Wis., Wyo.

Discussion

Juniperus horizontalis, a prostrate species, hybridizes with the trees J. virginiana and J. scopulorum (R. P. Adams 1983; N. C. Fassett 1945; M. Palma-Otal et al. 1983) and is closely related to both. The hybrid between J. horizontalis and J. scopulorum has been named J. × fassettii Boivin.

Selected References

None.

Lower Taxa

None.

... more about "Juniperus horizontalis"
not +  and visible +
elongate +  and hemispheric +
Obtuse (?) +  and Acute (?) +
Robert P. Adams +
Moench +
long-lived +
exfoliating +
angled +  and terete +
inconspicuous +  and undifferentiated +
Creeping juniper +, savinier +  and genévrier horizontal +
blue-black +  and brownish blue +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
globose +  and ovoid +
depressed +
St. Pierre and Miquelon +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. (Nfld.) +, N.W.T. +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Alaska +, Ill. +, Iowa +, Maine +, Mass. +, Mich. +, Minn. +, Mont. +, Nebr. +, N.H. +, N.Y. +, N.Dak. +, S.Dak. +, Vt. +, Wis. +  and Wyo. +
0–1000 m +
Sand dunes, sandy and gravelly soils, prairies, slopes, rock outcrops, and stream banks +
decurrent +  and scale-like +
petioled +, sessile +, twisted +  and simple +
overlapping +
green but turning reddish purple +
persisting +
conspicuous +
3 (?) +  and 5 (?) +
scale-like +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
spheric;oblong +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
fibrous;woody +
peltate +  and complex +
cuneate +  and oblong +
fleshy +  and woody +
overlapping +
persistent +
coalesced +
fibrous +  and obscurely woody +
1 +  and 2 +
1 +  and 2 +
round +  and faceted +
flattened +
wide +  and thin +
Juniperus horizontalis var. douglasii +  and Juniperus horizontalis var. variegata +
Juniperus horizontalis +
Juniperus sect. Sabina +
species +
flattened +, angled +  and terete +
upright +  and decumbent +
asymmetric +  and symmetric +