1. Broussonetia papyrifera (L.) L’Hér. ex Vent.
(paper mulberry)
Pl. 457 i, j;
Map 2078
Plants trees or
shrubs to 15 m tall, unarmed, with milky sap. Bark smooth or somewhat grooved
longitudinally, yellowish brown to grayish brown. Twigs relatively stout, often
somewhat zigzag, grayish green with circular, orange lenticels, densely
pubescent with spreading hairs, the winter buds bluntly ovoid, with several
overlapping scales, densely hairy. Leaves alternate and/or opposite. Petioles
3–11 cm long, densely pubescent with long spreading hairs. Leaf blades 8–19 cm
long, 5–16 cm wide, ovate, unlobed or shallowly to deeply 3-lobed and with 3
main veins from the base, abruptly short-tapered to a sharply pointed tip, the
lateral lobes (when present) also abruptly short-tapered, broadly angled to
rounded, truncate, or occasionally shallowly cordate at the base, the margins
otherwise toothed, the upper surface dark grayish green, roughened, with the
main veins more or less hairy, the undersurface pale green or off-white,
usually densely hairy, felty to the touch. Inflorescences entirely staminate or
pistillate. Staminate inflorescences solitary in the leaf axils, dense catkins
4–8 cm long, pendant, the calyces 1.5–2.5 mm long, deeply 4-lobed, hairy.
Pistillate inflorescences solitary in the leaf axils, dense, globose clusters
1–2 cm in diameter, the calyces 1.5–2.5 mm long, deeply 4-lobed, the lobes
oblanceolate, densely hairy at their tips, the stigma 1, unbranched, linear.
Fruits fused into compound, fleshy spherical masses, these 1.5–3.0 cm in
overall diameter at maturity, the individual drupes more or less club-shaped,
long-exserted from the persistent calyces, orange to orangish red. 2n=26.
April–May.
Introduced,
scattered in the southeastern quarter of the state, uncommon or absent elsewhere
(native of Asia, introduced in the eastern United States west to Nebraska and
Texas). Bottomland forests, mesic upland forests, and edges of sand prairies;
also ditches, railroads, roadsides, and disturbed areas.
Paper mulberry
persists at disturbed sites, most commonly in the Mississippi Lowlands
Division, often forming large, dense clonal colonies from root sprouts.
Pistillate inflorescences can be relatively showy, with the calyces bright red,
but nearly all of the fertile specimens collected in Missouri thus far have
been staminate.
Fiber from the
inner bark is made into cloth and paper in the Old World and the sap has been
used in the formulation of a glue. Steyermark (1963) noted that the pollen can
cause hay fever.