Guide to Privets (Ligustrum sp.)

 There are four privets in New Jersey: border (L. obtusifolium), common (L. vulgare), Chinese (L. sinense) and California (L. ovalifolium).

In central NJ border privet is vastly more commonly escaped than all the others put together. 

California privet has shiny twigs (branchlets) that are entirely smooth. All others have dull twigs.

Border privet is either deciduous or semi-evergreen. All the others are evergreen or semi-evergreen, so a privet with no leaves in late winter is border.

California privet always has pointed leaves.

Border privet never has pointed leaves (they are blunt, rounded or indented)

Chinese and common can have either pointed or rounded leaves. 

Common privet only has flowers/fruit at the ends of branches, never in the axils. All others can have axillary clusters of flowers/fruit. 

All privets can have flower/fruit clusters around 2 inches long. Only border privet can have clusters smaller than that. Chinese and California clusters can be up to 4 inches long.

Border and Chinese privets have dull, blue fruit (because of a bloom on the fruit). Every now and then this gets rubbed off, leaving shiny black fruit, but it's rare, and generally still present toward the center of the cluster.

Common and California privets have shiny, black fruit. 

Chinese privet has stems of individual flowers and fruit longer than 1/2 inch. All other privets have short stems

Chinese and common privet have flowers with petal lobes about equal to length of tube. Chinese also has reproductive parts sticking out well beyond the tube (common does not).

California and border privet have flowers with petal lobes much shorter than their very long tubes. (but California has shiny twigs and border has dull and hairy)

Border (and only border) can have 1-inch, pointed, somewhat thorn-like branchlets. They are not always present. 

To prove (or disprove) you have border privet:

when flowers are present: long tubes on flowers, twigs not shiny

when fruit is present:  fruit is dull blue, not shiny black; any fruit clusters are under 2 inches, also some clusters not terminal; stems of each fruit under 1/2 inch; whole cluster under 2.5 inches; stems of fruit hairy.

when only leaves present: leaves are not pointed, small twigs are not shiny, leaves are not thick and leathery. (This will not be enough to prove you have it, it only definitively rules out California). Also, a very close shot of hairs on small twigs will show them to be of very differing lengths (that would prove L. obtusifolium). Border privet is the only one with 1-inch, pointed, somewhat thorn-like branchlets, if you see these, it's definitive. 

when no leaves present (and healthy buds present): the only privet that will lose all its leaves in winter (and it doesn't always) is border. To prove it's not some other genus, make sure the buds and branches are opposite, the bark is not shreddy, no buds are more than 3 times larger than the smallest buds, no buds are more than 2 times longer than wide, no buds are red. Look for 1-inch, somewhat thorn like side branches (this is pretty much the only shrub with opposite buds and "thorns", if these are present). 

Holly Olive

Japanese Fringetree

White Ash

White Ash, Fraxinus americana twig and buds

White Ash, Fraxinus americana, twig and buds

White Ash, Fraxinus americana, twig and buds

White Ash likes dryer sites than Green (it's most common look-alike). The main cue is the notched or U-shaped leaf scars (Green Ash scars do not curve around the bud at all).

I remember White is upland and Green lowland by thinking of white, snow capped mountains, and green, marshy valleys, but you can find either one in either place.

White Ash seeds are narrower than Green's.

Ash seeds are samaras, or keys.

Ashes come in male trees and female trees. The females make the seeds, the males have more obvious flowers. The male flowers are often attacked by Ash Flowergall Mites which cause them to look dried and brown and to last throughout the year and into winter.

Scale insects like ash. Several clearwing moths are ash borers. Fall webworm likes ash. Morel mushrooms often grow at the base of the tree.

Fall color in ash is a maroon-green, not attractive. They are one of the first trees to change in fall, and one of the later trees to leaf out in spring.

Ash sap is flammable, so ash twigs can work well in a campfire even when green.

Ash tea is laxative, use as medication, not for food.

Lilac

Green Ash

Male flowers of Ash, Fraxinus sp.

Samaras (seeds) of Green Ash, Fraxinus pennsylvanica

twig and buds of Green Ash, Fraxinus pennsylvanica

twig and buds of Green Ash, Fraxinus pennsylvanica

mature bark of Green Ash, Fraxinus pennsylvanica

young bark of Green Ash, Fraxinus pennsylvanica

twig and buds of green ash, Fraxinus pennsylvanica

Ash flowergall mite attacked these male Green Ash flowers, Fraxinus pennsylvanica

mature bark of Green Ash, Fraxinus pennsylvanica

Green Ash is the most common ash here in the Watchung Mountains. It prefers moister soil than White Ash, its main look-alike. I remember this by picturing white-capped, snow-covered mountains, vs. green, marshy lowlands, but either species can be found in either place. 

Bud scars are probably the most reliable way to separate the two. Green Ash scars never curve up around the bud. White ash often do. Also green ash often (but not always) has red-wooly buds. 

Green ash seeds (samaras or keys) have longer "keels" (the flat parts) that extend up the sides of the rounded main part of the seed, whereas on White Ash samaras the flat part tends to ends about where the round part attaches to it. 

Ash trees have the sexes on separate trees. Only female trees produce fruit. Male trees have more obvious flowers, which come out in the spring before the leaves. Male flowers are often attacked by the Ash Flowergall Mite, which makes the flowers look dry and brown and they stay on the tree all year long, even through the winter. 

In the fall, ash leaves turn a maroon-green color (not pretty) and are among the first leaves to turn and fall. They are also very late to leaf out in the spring. 

Several clearwing moths are borers in ash. Scale insects like the stems. Fall webworm is fond of ash. Morel mushrooms often grow beneath, and old ash leaves are good for earthworms. 

Ash sap is flammable, which means you can use ash wood in campfires even when it's still green. 

Ash extracts are laxative, and the plant is not useful for food.

Border Privet (Ligustrum obtusifolium)

Forsythia

Winter Jasmine

I went to The Grounds for Sculpture near Trenton, NJ on March 30, 2013. There were only a few flowers blooming. Several people glanced at this and dismissed it as Forsythia, but it turns out to be Winter Jasmine, Jasminum nudiflorum .

The tubular, yellow flowers come out before the leaves, leading to another common name: Naked Jasmine. (I searched images by this name without thinking, and did not get a single botanical picture). It is native to China and is not naturalized here in NJ, though it is quite hardy.