Privets in the sanctuary, oh my!
We had six Master Naturalists working out in the Heard Sanctuary today, pulling up about 600-700 linear feet of barbed wire in the sanctuary. It was actually more fun than it might sound, since the weather was good, the company of other Master Naturalists is always great, and we got to see some interesting plants, insects, and fungi. We did get into a spirited (but not heated) discussion of the various types of privet growing out there. Parviz has been working hard on getting all the privets out of the sanctuary, but today we were working in a section that he hasn’t yet reached, so we had several samples of each species. I felt pretty confident about Chinese Privet and Quihoui Privet, except how to pronounce Quihoui (kwee-WHO-ee, according to today’s research.) I wasn’t at all sure about Japanese Privet, though, as I’ve been calling all privets with large leaves Glossy Privet. After an hour or so in my FNCT, here’s what I’ve come up with:
All of the privets growing here are introduced invasives which have escaped from cultivation. They are shrubs or small trees, evergreen or semi-deciduous, and have opposite leaves.
Two common types of privet have glabrous twigs and large leaf blades, 2.5-6" long. These are both evergreen.
• The first of these is Glossy Privet, Ligustrum lucidum. It can grow to be a tree up to 30 ft. tall, or occasionally taller. Glossy Privet leaves are large, 3-6" long, with 6-8 or more distinct veins on each side of the midrib. The leaves are glossy and hairless. Glossy Privet leaves taper to a narrow point and the petiole (stalk) of the larger leaves is up to 3/4" long. In the flowers, the tube of the corolla equals the lobes in length.
• The second of the large-leaf privets is Japanese Privet, L. japonicum. It is a smaller shrub or small tree, usually not much more than 10 ft. tall. The leaf is somewhat smaller than that of Glossy Privet, up to about 2.5 -4" long. Leaves have only about 4-5 indistinct veins on each side of the midrib. The leaf shape is less pointed than that of L. lucidum, and it has a shorter petiole, usually less than 1/2" long.
Two common types of privet have pubescent (fuzzy/hairy) twigs and small leaves. These are semi-deciduous, evergreen in mild winters.
• The most widespread invader is Chinese Privet, Ligustrum sinense. It is a shrub growing to about 12 ft. tall. Its leaves are 1 - 2.5" long and usually hairy along the midrib on the underside. The leaf shape is a rounded diamond or an egg shape. The flowers are in compact clusters, with the corolla tube shorter than the lobes.
---A similar privet is Ligustrum vulgare, or Common Privet. It is native to the Mediterranean area, but it is
cultivated here, and possibly escapes. It is very similar to L. sinense, but the leaves are hairless on the
underside.
• The other small-leaf privet is Quihou Privet, L. quihoui. The leaves are 1 - 2.5" long, dark green, usually oblanceolate (teardrop shaped, narrowest near the stem) and hairless on the underside. The leaf base tapers all the way to the twig, appearing to have almost no petiole. Flowers are in whorl-like, separated clusters at tips of branches and on paired side branchlets, forming into loose clusters. The corolla tube is about equal to the lobes.
I happened to find a very handy key to the privets at Texasinvasives.org. It's a one page pdf, with pictures, and it's even better than my journal. Here's the link:
https://www.texasinvasives.org/invaders/CS_Resources/PrivetKey.pdf