Tsuga Carrière

Hemlock (en), Tsuga (fr)

Genus

Gymnosperms > Pinales > Pinaceae

Characteristics

Trees evergreen; crown conic; leading shoot usually drooping. Bark gray to brown, scaly, often deeply furrowed. Branches horizontal, often tending to be arranged in flattened "sprays" and arched downward; short (spur) shoots absent; young twigs and distal portions of stem flexuous and pendent, roughened by peglike projections persisting after leaves fall. Buds mostly rounded at apex, not resinous. Leaves borne singly, persisting several years, ± 2-ranked or radiating in all directions, flattened to somewhat angular; abruptly narrowed to a petiolelike base, set on peglike projections, these angled, projected forward, sheath absent; apex rounded or notched; resin canals 1. Cones borne on year-old twigs. Pollen cones solitary, globose, brown. Seed cones maturing in 1 year, shedding seeds and falling soon thereafter or persisting for several years, pendent, ovoid, oblong, or oblong-cylindric, sessile or nearly so; scales persistent, shape various, thin, leathery, lacking apophysis and umbo; bracts small, included. Seeds winged; cotyledons 4--6. x =12.
More
Trees evergreen; branches irregularly whorled; branchlets with leaf cushions and persistent winter bud scales at base; winter buds ovoid or globose, not resinous. Leaves pectinately arranged, rarely radially spreading (emerging in false whorls on lateral branchlets), petiolate; petiole twisted at base; blade usually linear and flattened, stomatal lines abaxial, rarely on each surface, in 2 white bands, separated by an elevated midvein, vascular bundle 1, resin canal 1 below vascular bundle. Pollen cones growing from lateral buds, solitary, rarely clustered in umbels from a single bud, ellipsoid or ovoid; pollen with ring-shaped, saccate structure near distal pole, rarely ± 2-saccate. Seed cones terminal (rarely lateral) on 2nd-year branchlets, solitary, pendulous, rarely erect, ovoid-globose to cylindric or obovoid-oblong, maturing in 1st year. Seed scales thin, woody, persistent. Bracts included, rarely with slightly exserted, apical cusp. Seeds small, with small resin vesicles adaxially. Cotyledons 3-6. Germination epigeal. 2n = 24*.
Male cones axillary near the tip of the twigs of the previous season, peduncled, globose; female cones terminal on lateral branches of the previous season, pendulous on a short peduncle, the persistent scales much larger than the minute bracts; evergreen trees, the flat lvs jointed at the base to minute, persistent sterigmata; resin-duct 1 in each lf; 2n=24. 14, temp. Asia and N. Amer.
Life form annual
Growth form tree
Growth support -
Foliage retention evergreen
Sexuality monoecy
Pollination -
Spread -
Mature width (meter) -
Mature height (meter) -
Root system -
Rooting depth (meter) -
Root diameter (meter) -
Flower color -
Blooming months -
Fruit color -
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway -

Environment

Light -
Soil humidity -
Soil texture -
Soil acidity -
Soil nutriment -
Hardiness (USDA) 4-9

Usage

Uses -
Edible -
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Mode -
Germination duration (days) 7 - 60
Germination temperacture (C°) 15
Germination luminosity -
Germination treatment stratification
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Tsuga unspecified picture

Distribution

Tsuga world distribution map, present in China and United States of America

Identifiers

LSID urn:lsid:ipni.org:names:11721-1
WFO ID wfo-4000039518
COL ID 6486F
BDTFX ID 87363
INPN ID 198722
Wikipedia (EN) Link
Wikipedia (FR) Link

Synonyms

Tsuga Hesperopeuce Hesperotsuga

Lower taxons

Tsuga caroliniana Tsuga dumosa Tsuga chinensis Tsuga forrestii Tsuga sieboldii Tsuga x jeffreyi Tsuga mertensiana Tsuga diversifolia Tsuga heterophylla Tsuga canadensis