Identification of Palm Trees | Austin Bat Refuge

Identification of Palm Trees

In the Austin, Texas, Area: A Casual Guide for Distinguishing our Native Sabal mexicana from the Aliens.

By Landon Lockett

lockett@ev1.net

Sabal mexicana, aka Sabal texana

Common name: palm tree. Among nurserymen: texana.
Leaf: green green. The underside of the Sabal mexicana leaf curves downward, so that if you see it from the side the underside makes a semicircle. The leaf segments grow upwards so that if you look at it from the end it has a V shape. It is clearly a 3D thing. All this is called a costapalmate leaf.
Leaf threads: leaves have a tangle of threads.
Leaf stem: not toothed (won’t bite)
Fruit: size of an olive, and tastes like a date (but not much meat). S. mexicana blooms in about May, with plumes of tiny white flowers bunched in with leaves. Fruit ripens in Oct.-Nov. Doesn’t bloom every year. One year when we had a rainy fall there was a S. mexicana in Boerne that bloomed in the spring and then again in the fall, so that it had flowers and fruit at the same time.
Crown: Round when seen from a distance, and if the dead leaves have not been trimmed.
Trunk: medium thickness.

Found in older residential areas (Hyde Park, Heights Blvd, Rio Grande from MLK south), farmhouses, older public buildings, UT campus, Mayfield Park, Laguna Gloria.) Decades ago the older ones were wrenched from the wild and, without any say-so on their part, planted in these sterile places. Still reproduces almost wherever planted, even in the badlands of Dallas. Because it is a native Texas palm S. mexicana is the Austin palm tree that, once planted, most commonly reproduces. Young seedlings look like grass, may be thick under parent. The exotic palm trees in Austin rarely reproduce.
Native to: Texas & Mexico. Due to extirpation in 19^th century, northern limit of range unknown.
Comment: Most people, seeing a trunkless palm coming up in some odd spot in Austin, assume it is S. minor, but it is probably young S. mexicana. Note bright green leaf and tangle of leaf threads to distinguish it from S. minor. Remember the palm in back of the library on Exposition. And when you see a young S. mexicana look for parent not far away.

Sabal minor

Common name: Dwarf Palmetto, or just palmetto. In East Texas “palmiter”
Leaf: dark, bluish green; palmate, more or less flat . “Palmate” means the leaf segments radiate out from a single point, like the segments of a collapsible hand fan. Actually S. minor is costapalmate, but only slightly so, so that we think of it as palmate.
Leaf threads: only a few
Leaf stem: unarmed (has no thorns).

Fruit: Dark, size of a pea, slightly sweet, but is mostly seed and skin. Flower stalk (inflorescense) longer than leaves and goes straight up, then bends over as fruit develops. Blooms about May.
Crown: The crown is the bunch of leaves at the top of the trunk of a palm tree. Since S. minor hardly ever has a trunk, we don’t normally speak of S. minor as having a crown, since it would just be the leaves emerging from the ground. In other words from what we see it is all crown.
Trunk: is underground, so that S. minor is actually a tree with an underground trunk. Try digging one up and you will see. But sometimes the trunk emerges to form an aboveground tree. Some trunks in Louisiana may be 9 feet or so tall, but the tallest I’ve seen in Texas is six feet. This one is on the bank of the Brazos in Brazoria County (but don’t confuse it with the much larger Brazoria County hybrids). If you want to see trunked S. minor go to the Winters Bayou Scenic Area in the Sam Houston National Forest, northwest of Conroe. Trunks there top out at 4 1/2 feet. According to researchers at Tulane U who study them trunked S. minor are hundreds of years old.

Found in the wild locally, mainly on the southern fringe of Austin, and northwest, in the Pedernales Canyon, including West Cave.
Native to: Texas, SE Oklahoma, and on east.

Washingtonia filifera

Common name: palm tree, Washingtonia
Leaf: is in a single plane (more or less). In other words it’s palmate.
Leaf threads: leaves have a tangle of threads
Leaf stem: armed (toothed). No Texas native palm has thorns.

Fruit: Small, dark, elongated. Borne on long inflorescences that arch up out of the crown, then go downward. Inflorescences appear in Spring.
Crown: Seen from a distance, and if the dead leaves have not been trimmed, it has the shape of an inverted tear drop. This distinguishes it from the crown of S. mexicana, which is round.

Trunk: heftier than any other palm in Austin. May be riddled by woodpeckers.
Planted locally: Palm School, and many other places. The most commonly planted palm in Austin, but I’ve never seen it reproduce here.
Native to: California, northwestern Mexico, Arizona and probably Nevada. Planted all around the world, to make places look tropical when they are not.

Sabal palmetto

Common name: Cabbage palmetto, palmetto, palm tree.
Leaf: not in a single plane, the middle of it curves down and segments turn up. It is costapalmate, even more than S. mexicana.
Leaf threads: leaves have tangle of threads.
Leaf stem: not armed
Fruit: size of pea. This best way to distinguish it from S. mexicana, which has fruit the size of an olive.
Crown: small compared to S. mexicana.
Trunk: not dinky, but fairly skinny.
Planted locally: shopping centers, Taco Cabanas, etc.
Native to: Florida and coastal Georgia and Carolinas, Bahamas, Cuba. It’s the native palm that grows all over the place in Florida. There they dig them up full grown and ship them, without their consent, to Texas and plant them wherever someone wants an instant palm tree.
Quick and dirty way to distinguish S. mexicana from S. palmetto: S. mexicana grows in older neighborhoods, S. palmetto grows in front of new commercial buildings. S. mexicana has a larger crown, and its leaves are less costapalmate, than S. palmetto. But the only way to positively tell them apart is by fruit size.

Trachycarpus fortunei

Common name: Windmill Palm. “Trachy” to its intimates.

Leaf: palmate.
Leaf threads: ?
Leaf stem: ?
Fruit: Exists.

(Because it is an obvious exotic, readily distinguishable by its dinkismo, I never bothered to examine one closely. S. mexicana is massive in comparison.)

Crown: dinky
Trunk: dinky, with burlap-looking fiber.
Planted locally, but you have to look close or you will miss it.

Native to: China.
Comment: A palm only a landscaper could love. I call it the swizzle-stick palm. Likes to be scratched just below crown.

Date palm

Common name: Date palm, palm tree.

Leaf: pinnate leaves (like those of a coconut palm). That is, the segments stick out parallel from a long midrib, like the segments of a feather (thus the name). No Texas native is pinnate.
Leaf threads? I just never checked that out. Those date palms on West 6^th are too tall. Volunteers?
Leaf stem: presumably has one.
Fruit: DATES. What else???
Crown: I avoid getting too chummy with this species here because I know they are doomed.
Trunk: Exists
Planted locally (occasionally): Towering palms in front of ad agency on north side of west 6th about a block east of Lamar.

Native to: Eastern and southern Mediterranean, and on east. Picture camels, pyramids and an oasis.
Comment: Will die in first severe, once-in-a-decade freeze. In Austin the only escape from cultivation (spontaneous reproduction) I know of for this species grows out of the sidewalk in front of Wheatsville Co-op. Evidently the Wheatsville Co-op sells dates and their customers are not fastidious about where they spit the seeds. If it survives they might have to get some camels to go with it.

Butia

Common name: Butia, pindo palm. In its native Brazil: Butia (with accent on the “a”) .
Leaf: gray green, pinnate, with a peculiar arching profile I can’t describe.
Leaf threads: Never checked.
Leaf stem: exists.
Fruit: I’ve read you can make jelly out of it.
Crown: It has one. See second bullet, above.
Trunk: short but exists.

Planted locally: There is one in front of the Taco Cabana just south of the Container Store at the SE corner of 183 and 360. Also there is one next to the parking area at the Zilker Garden Center. The only pinnate palm in the Center. Imagine. They have exotics like this, but no Sabal mexicana—except for a young escape that sneaked into the woods beside their flower bed. Nature always tries to get even.
Native to: southern South America.
Comment: I’ve seen them in the wild in southern Brazil. Commonly planted in southeast US, occasionally in Austin, more in Houston. Austin’s most extreme freezes might kill it. Although people assume all palms are tropical, none of the exotics described here come from the tropics. Where I’ve seen butia in Brazil is the same latitude as Austin, only south. The range of Sabal palmetto extends into the Caribbean, but the ones we get here come from Florida.

Cycad. Common name: Sago palm. Looks like a palm but ISN’T. Smaller than any palm here, except maybe S. minor. Dark green pinnate leaves that look sorta like ferns.