Key to Sorbus

View taxon page for Sorbus

(For a list of species in Sorbus, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Hairs of stem-buds, 

leaflet 

A leaf-like unit of a compound leaf; distinguished from a leaf by the absence in its axil of a bud, branch, thorn, or flower; lacking lateral, basal appendages (stipules); either simple (leaf 1-compound, with primary leaflets) or compound (leaf 2-compound, with primary and secondary leaflets; 3-compound, with primary, secondary, and tertiary leaflets, etc).

 axils, 

leaf 

Organ arising from a stem, generally composed of a stalk (petiole) and a flat, expanded, green, photosynthetic area (blade); distinguished from a leaflet by the presence in its axil of a bud, branch, thorn, or flower; sometimes with lateral, basal appendages (stipules); either simple (toothed, lobed, or dissected but not divided into leaflets) or compound (divided into leaflets).

axils, inflorescence ± white or ± gray

2. Leaflets dull adaxially, 11–17; stem-bud not shiny, not sticky, hairs dense ..... [S. aucuparia]

2' Leaflets shiny adaxially, 7–13; stem-bud shiny, sticky, hairs generally sparse ..... S. scopulina

1' Hairs of stem-buds, leaflet axils, leaf axils, inflorescence primarily red-brown

3. Leaflets shiny adaxially, 2–4 cm; stem-bud shiny, sticky, not glaucous, hairs generally only on 

scale 

1. Wide, appressed, membranous, epidermal outgrowth (e.g., Cheilanthes covillei) 2. Structure partially or entirely covering an over-wintering bud (bud scale) (e.g., Salix goodingii bud). 3. In gymnosperms, a woody, seed-bearing structure attached to the cone axis (cone scale) (e.g., Abies magnifica). 4. In Asteraceae, a flat, membranous pappus element (e.g., Hymenoxys hoopesii). Leaves or bracts may be scale-like in one or more of the preceding ways.

 margins, tips; flower, fruit 

pedicel 

Stalk of an individual flower in an inflorescence, or the corresponding structure in fruit.

± glabrous ..... S. californica

3' Leaflets dull adaxially, 2–6 cm; stem-bud glaucous, not shiny, not sticky, hairs on scale margins, tips, faces; flower, fruit pedicel glabrous or ± hairy ..... S. sitchensis

4. Lateral leaflets ± 

entire 

Having margins that are continuous and smooth (i.e., without teeth, lobes, etc.).

or toothed above middle ..... var. grayi

4' Lateral leaflets toothed below middle ..... var. sitchensis

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