Heteromeles

M. Roemer

Fam. Nat. Syn. Monogr. 3: 100, 105. 1847.

Common names: Christmas berry toyon
Etymology: Greek heteros, different, and melon, apple, alluding to low stamen number
Treatment appears in FNA Volume 9. Treatment on page 447. Mentioned on page 429, 449, 468, 488.

Shrubs or trees, canopies dense, 20–100 dm. Stems usually 1; bark (trunk) grayish, with fine tan to dark gray striations, ± smooth; short-shoots absent; unarmed; young stems puberulent. Leaves persistent, cauline, simple; stipules variably persistent, free, minute, margins unknown, apex gland-tipped; petiole present; blade ± elliptic to narrowly elliptic or narrowly oblong, 5–15 (–20) cm, leathery, margins revolute, sharply, remotely serrate, venation pinnate (craspedodromous-brochidodromous), surfaces tomentose when young, glabrescent. Inflorescences terminal, 20–150-flowered, panicles, ± dome-shaped, white-tomentose; bracts present on proximal nodes, leaflike, plus numerous, scalelike appendages on axes; bracteoles present caducous, delicate. Pedicels present. Flowers: perianth and androecium epigynous, 10 mm diam.; hypanthium urceolate, 2–4 mm, glabrous or weakly floccose; sepals 5, suberect, triangular; petals 5, white, irregularly round, base weakly clawed; stamens 10, shorter than petals; carpels 2 or 3, distinct, basally adnate to hypanthium, styles 2 or 3, lateral, distinct; ovules 2. Fruits pomes, usually bright red, sometimes yellow, ellipsoid, 5–10 mm, glabrous or glabrate; flesh mealy; hypanthium persistent; sepals persistent, accrescent over hypanthial opening. Pyrenes 2 or 3 per fruit, carpel walls thin, soft; styles not persistent; seeds 1 per pyrene, large.

Distribution

Calif., nw Mexico

Discussion

Species 1.

Heteromeles resembles Aronia and Photinia; it differs by having 10 stamens instead of 20, nearly free carpels (versus fully connate), and fruit flesh lacking stone cells (versus often possessing some). Its fruit is of the coreless type (J. R. Rohrer et al. 1991). Molecular evidence (D. Potter et al. 2007) shows a relationship to the Asiatic Eriobotrya and Rhaphiolepis Lindley miniclade; fruit type, notched petals, and other characteristics agree.

Selected References

None.

... more about "Heteromeles"
10 cm100 mm <br />0.1 m <br /> (?) +
gland-tipped +
scale-like +
James B. Phipps +
M. Roemer +
compound +  and simple +
opposite +  and alternate +
less elliptic +  and narrowly elliptic +
adnate +  and distinct +
Christmas berry +  and toyon +
Calif. +  and nw Mexico +
not +  and aggregated +
Greek heteros, different, and melon, apple, alluding to low stamen number +
unisexual +  and bisexual +
not +  and aggregated +
not +  and aggregated +
yellow +  and bright red +
glabrate +  and glabrous +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
floccose +  and glabrous +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
crassinucellate +
persistent +
pinnate +  and serrate +
toothed +, unlobed +  and lobed +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and basal +
white-tomentose +
dome--shaped +
10 cm100 mm <br />0.1 m <br /> (?) +
0 (?) +  and 4 (?) +
free +  and distinct +
adnate +, free +, connate +  and distinct +
Fam. Nat. Syn. Monogr. +
not arillate +
persistent +
free +  and distinct +
triangular +
accrescent +
free +  and distinct +
branched +  and simple +
tan +  and dark gray +
not persistent +
distinct +
elongate +
glabrescent +  and tomentose +
Heteromeles +
Rosaceae tribe Gillenieae +
inconspicuous +
tree +  and shrub +
17 +, 15 +, 9 +  and 8 +