Key to Prunus

View taxon page for Prunus

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

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

1. Inflorescence an elongate 

raceme 

In flowering plants excluding Asteraceae, Cyperaceae, Poaceae, and some other groups, an unbranched inflorescence in which the flowers are borne on pedicels and nearly always open from the bottom to the top of the inflorescence. 2. In Asteraceae, Cyperaceae, Poaceae, and some other groups, a raceme-like inflorescence is one in which the inflorescence units (e.g., heads in Asteraceae; spikelets in Cyperaceae and Poaceae), instead of individual flowers, are stalked and attached directly to the main axis of the inflorescence, not to branches, and in which floral development may or may not proceed as in 1.

, flowers 15–many

2. Leaves deciduous, finely 

serrate 

Having margins with sharp, fine to coarse teeth generally pointing tipward, not outward; margins with such teeth on such primary teeth are doubly serrate.

; inflorescence leafy at base; fruit 6–14 mm ..... P. virginiana var. demissa

2' Leaves evergreen, 

entire 

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

or spiny-serrate; inflorescence leafless at base; fruit 12–25 mm ..... P. ilicifolia

3. Leaf margin spiny-serrate, ± wavy, 

blade 

Expanded portion of a leaf, petal, or other structure, generally flat but sometimes rolled, cylindric, wavy, or cupped.

widely 

ovate 

Egg-shaped (i.e., widest below the middle) in two dimensions (i.e., in one plane), as a leaf.

to round; 

petiole 

Leaf stalk, connecting leaf blade to stem; sometimes more or less indistinct.

3–10 mm; s NCoR, CW, SW (except ChI) ..... subsp. ilicifolia

3' Leaf margin generally entire, flat, blade generally ovate; petiole 8–25 mm; ChI ..... subsp. lyonii

1' Inflorescence a short, ± flat-topped raceme of (3)6–12 flowers, or umbel-like to subsessile cluster of 2–5 flowers, or flowers 1

4. Ovary, fruit generally glabrous

5. Inflorescence a raceme; sepal entire; fruit 7–14 mm; twigs with true terminal 

bud 

1. An incompletely developed, more or less embryonic shoot, usually covered with bud scales. 2. An unopened flower, often protected by sepals.

..... P. emarginata

5' Inflorescence an umbel-like cluster or flowers 1; sepal gland-toothed to nearly entire; fruit 15–30 mm; twigs with false terminal bud

6. Leaf blade 

elliptic 

In the shape of a flattened circle or ellipse; wider than linear

to (ob)ovate, base 

obtuse 

Having a short-tapered, blunt tip or base, the sides convex or straight and converging at more than a right angle.

; flowers 1(2), appearing before leaves; tree, roadsides, streambanks, chaparral as waif ..... P. cerasifera

6' Leaf blade oblong-ovate to ± round, base rounded to subcordate; flowers 2–5, appearing with leaves; shrub, mixed-evergreen or conifer forest ..... P. subcordata

4' Ovary, fruit densely 

puberulent 

Minutely hairy.

or velvety

7. Tree 3–10 m, not thorny; 

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).

blade 25–150 mm; fruit 25–80 mm; petals 10–25 mm

8. Petiole (8)10–25 mm; leaf blade 25–100 mm; petals pink to nearly white; fruit pulp leathery ..... P. dulcis

8' Petiole 5–10(15) mm; leaf blade (50)70–150 mm; petals dark pink; fruit pulp fleshy ..... P. persica

7' Shrub < 4 m, often thorny; leaf blade 5–30 mm; fruit 7–18 mm; petals 1.4–12 mm

9. Leaf blade < 2 × longer than wide, base wedge-shaped to rounded or subcordate

10. Leaf blade ovate to obovate, ± hairy, base wedge-shaped to obtuse; flowers generally unisexual; 

hypanthium 

Structure generally in the shape of a tube, cup, or bowl, derived from the fused lower portions of the perianth and stamens, from which these parts seem to arise, and to which the ovary wall is fused in an inferior ovary (to which the ovary wall is partially fused in a half-inferior ovary; from which the ovary is free in a superior ovary).

, sepals densely puberulent abaxially ..... P. eremophila

10' Leaf blade ovate to round, glabrous, base obtuse to rounded or subcordate; flowers 

bisexual 

Both male and female reproductive parts occurring and functional in the same plant or structure (e.g., flower, spikelet, inflorescence).

; hypanthium, sepals glabrous abaxially ..... P. fremontii

9' Leaf blade >= 2 × longer than wide, base long-tapered

11. Petals (5)8–11 mm, dark pink to nearly white; 

pedicel 

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

(1)4–12 mm; leaf blade 2–6 mm wide, finely serrate ..... P. andersonii

11' Petals 1.4–4 mm, white to ± yellow; pedicel 0–4 mm; leaf blade 1–2(4) mm wide, generally entire ..... P. fasciculata

12. Leaf puberulent; s SNF, Teh, s SCoRI, n TR, e PR, D ..... var. fasciculata

12' Leaf glabrous to low-papillate; s CCo, s SCoRO ..... var. punctata

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