Mulberries in North America

(in progress)

Morus alba (white mulberry) Morus nigra (black mulberry) Morus rubra (red mulberry)
Broadly naturalized in North America Not known to naturalize in North America, but sometimes planted Broadly native to central/eastern North America
Fruits white, pink, red, purple, or black at various stages (might be any color when ripe) Fruits white, pink, red, purple, or black at various stages (colors when ripe?) Fruits white, red, purple, or black at various stages (usually black/purple when ripe)
Fruits mostly stubbier (length to width ratio mostly 1.5 to 3) ? Fruits mostly longer (length to width ratio mostly 2.5 to 4)
Buds small, tannish-brown; twigs pinkish-brown Buds large, dark brown/black Buds large, reddish-brown; twigs pale tan
Leaves lobed or unlobed, often deeply lobed ? Leaves lobed or unlobed (less commonly or deeply lobed)
Leaves mostly 3 to 8 cm wide, rarely more than 15 cm long ? Leaves mostly 8 to 22 cm wide, larger leaves often more than 15 cm long
Leaves mostly hairless and glossy on the surface; brighter yellowish green Leaves roughly hairy on the surface, dull Leaves roughly hairy on the surface, dull, slightly wrinkly/rugose; bluer-green
Few, short hairs on the leaf back (0.2-0.5 mm), primarily on major veins Hairy (expand) Many, longer hairs on the leaf back (0.4-0.7 mm), all over
Leaf tip not commonly elongated like a lil tail ? Leaf tip often caudate/acuminate/elongated (like a lil tail)

(Morus microphylla not yet included here)
(are there other spp in Mexico?)
what else?

Sources:

As of 19 June 2022 there are about 2,750 obs (2,100 Needs ID, 200 RG) of Morus nigra in North America on iNat, most of which are misidentified Morus alba. You can help out with ID here!

Posted on June 19, 2022 04:54 PM by bouteloua bouteloua

Comments

Excellent start on a badly needed comparison chart.

Not sure if maybe most or all reports of M. nigra in North America are really just M. alba?

What gets called "M. alba" in Europe often has very large leaves, much different than anything I've seen in North America. Not sure what's going on with that.... just different cultivars that have become predominant in different continents?

Posted by whiteoak almost 2 years ago

yeah I think 99% of those NA obs of M. nigra are people thinking black fruit = black mulberry, and then the misconception being compounded by computer vision suggestions. I've started chipping away at reidentifications but it will be a long haul.

Posted by bouteloua almost 2 years ago

According to my Golden Guide to Trees (Brockman 1979), Morus nigra leaves are "rarely lobed." The illustration shows an unlobed, cordate leaf.

Posted by jasonhernandez74 9 months ago

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