Pyrus calleryana Descn., Callery pear. Shrub to small tree, winter–deciduous, twigs somewhat zigzagged and with short lateral shoots (determinate spur shoots) often spine–tipped, in range to 450 cm tall; shoots with only cauline leaves
Stems ridged, with 3 ridges from each leaf aging cylindric, ridges visible on 1–year twigs, initially tomentose with orangish to grayish hairs aging glabrescent and reddish; bark dull brown.
Leaves helically alternate, simple, petiolate, with stipules; stipules 2, attached to petiole < 2 mm from base, abscising during early leaf development, linear, 5—7 × 0.4 mm, sparsely ciliate on margins; petiole channeled with 2 ridges on upper side, to 35 mm long, soft–hairy aging glabrescent; blade ovate, 32—80 × 22—52 mm, tapered at base, low–crenate and sometimes wavy on margins, margins initially soft–ciliate and with minute red appendage near each notch, acute to acuminate at tip, pinnately veined with principal veins somewhat raised on both surfaces, aging with few hairs but especially midrib and approaching margins conspicuously soft–hairy.
Inflorescence raceme, terminal on short spur shoots (sessile above cataphyll cud scales), to 12–flowered, flowers helically alternate, bracteate; rachis at anthesis to 8 mm long, sparsely soft–hairy and having pale orange hairs < 1 mm long; bractlet subtending pedicel early–deciduous, narrowly acuminate–lanceolate, 6—7 × 0.5—1 mm, white and glabrous to midpoint, above midpoint light–orange and densely hairy; pedicel at anthesis 9.5—13 mm long increasing in fruit, having a short ledge of bractlet at base, with a pair of opposite bracteoles below midpoint, bracteoles linear, to 4 × 0.3 mm, lower portion white and glabrous with glandular teeth on margins, upper 1.5 mm light orange and hairy like bractlet
Flower bisexual, radial, in range 23—26 mm across, ± strongly scented; hypanthium broadly vase–shaped, 2.3—2.5 × 5 mm, green becoming white above midpoint from tissues of filaments and hypanthium rim somewhat wavy; sepals 5, attached to rim of hypanthium, in flower ± reflexed, triangular, ± 2.5 × 2 mm, green with narrow whitish margins and aging reddish at tip, margins and upper surface soft–puberulent, hairs on margins somewhat orangish and with several minute, orangish glandular teeth approaching tip, lower surface glabrous; petals 5, spreading and easily dislodged, short–clawed and roundish, 8—13 × 5.5—9 mm including claw ca. 1 mm long, white, limb margins wavy or toothed, veins radiating from claw and visible but not pigmented; stamens ca. 20 in 2 series, 1 opposite each petal claw and 3 opposite each sepal, free; filaments of alternating lengths of outer > inner, 3.5—6.3 mm long, white, in bud curved inward later ± straight and widely spreading, glabrous; anthers dorsifixed, dithecal, 0.9—1.1 mm long, white and rose–red aging darker, longitudinally dehiscent; pollen whitish; pistil 1; ovary inferior, bell–shaped, at anthesis 1.7—2 × 1—1.2 mm, green, glabrous or essentially so, 2–chambered, each chamber with at least 2 ovules; nectary on top of ovary; styles 2(—3), free from base, 5—5.5 mm long, pale green, glabrous; stigmas terminal, green, short–papillate.
Fruit pome, core containing 2 chambers, mostly 3—4–seeded, spheroid, 9.5—11 × 8.5—11 mm, olive with numerous tan lenticels; mesocarp juicy but relatively firm, 1—2 mm thick, greenish, tart; core bony, 5.5—6 mm diameter, yellowish, from inner side tissue appearing honeycombed.
Seed hemi–ovoid or 3–sided rounded on back and flat on 1 or 2 faces, 4—5 × 3 mm, in fresh condition (embedded within core) green, rounded.
A. C. Gibson