What Is This Thing? Oenothera triloba fruit

What Is This Thing? Oenothera triloba fruit

February 23, 2018

"What is this thing???"

We often hear this question from friends and family in relation to natural "treasures" found in the landscape. Sticks, leaves, flowers, fruit, fungi, lichens, moss. You name it, somebody has likely brought it to BRIT for identification at some point (or emailed us a photo).

The object below was brought in recently by a Fort Worth resident. Roughly the size and shape of a pine cone, this is actually an aggregation of many fruits (capsules) from a plant called stemless evening-primrose (Oenothera triloba). A winter annual, this native wildflower comes up in disturbed places (and often lawns) at the end of the year, overwinters as a rosette, then produces yellow flowers in the spring. Flowers arise from the base of the plant, meaning fruit eventually develop at the base as well. As the soft green parts of the plant die away, these tough bunches of fruit are left behind at ground-level. (And I do mean tough, so watch your step!)

Cluster of fruits from Oenothera triloba (stemless evening-primrose), ~12 cm in length.
Each individual fruit is 4-winged and contains 70+ seeds. Viewed from above, a single capsule looks like an "x".

Despite being super cool and super weird, there's not much information available on the web about these fruits. Though the species itself is widely distributed across the eastern-to-southeastern part of the country, that distribution is patchy, and the plant is uncommon throughout its range. It's even considered threatened in Kentucky and extirpated (locally extinct) in Indiana. All the more reason to carefully document those occasions when we DO spot it in our local landscapes! 

Excerpt from Shinners & Mahler's Illustrated Flora of North Central Texas (1999):
Oenothera triloba
Nutt., (three-lobed), STEMLESS EVENING-PRIMROSE, THREE-LOBED-PRIMROSE. Nearly stemless winter annual with numerous basal rosette leaves varying from entire to deeply lobed; flowers opening near sunset; hypanthium 2–10 cm long; sepals 1–1.8 cm long; petals pale yellow; capsules obpyramidal, 1–2 cm long, 4-winged apically, borne at base of plant. Grassy areas, disturbed soils, lawn weed; Blackland Prairie w to Rolling Plains and s to Edwards Plateau. Mar–Apr.

Oenothera triloba photo
Photo by Clarence A. Rechenthin, hosted by the USDA-NRCS PLANTS Database

 

Line drawing of Oenothera triloba
Illustration of Oenothera triloba from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 2: 604.

 

Links to more info on the species...

So keep bringing us your weird and wonderful treasures! We'll do our best to turn them into teaching moments that benefit us all. Happy botanizing!

 

References:
  • Britton, NL & A Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York, USA. Vol. 2:604.
  • Correll, DS & MC Johnston. 1970. Manual of the Vascular Plants of Texas. Texas Research Foundation, Renner, Texas, USA.
  • Diggs,GM, Jr, BL Lipscomb, & RJ O'Kennon. 1999. Shinners and Mahler's Illustrated Flora of North Central Texas. Sida, Bot. Misc. 16. Botanical Research Institute of Texas Press, Fort Worth, Texas, USA.
  • USDA, NRCS. 2018. The PLANTS Database (http://plants.usda.gov, 23 February 2018). National Plant Data Team, Greensboro, NC 27401-4901 USA.

 

Leave A Response

Restricted HTML

  • Allowed HTML tags: <a href hreflang> <em> <strong> <cite> <blockquote cite> <code> <ul type> <ol start type> <li> <dl> <dt> <dd> <h2 id> <h3 id> <h4 id> <h5 id> <h6 id>
  • Lines and paragraphs break automatically.
  • Web page addresses and email addresses turn into links automatically.

Related Articles

The Living Herbarium: Instructions for Life

Article originally published in The Leaflet (April 2014) by Brian Witte, PhD, BRIT Research Associate (Disclaimer: The technical aspects of this article are dramatically simplified in the interests of communicating with an audience entirely unfamiliar with molecular biology. Send me an email ( bwitte@brit.org ) if you would like a deeper explanation.) We like to repeat, loudly and often, that there are over 1 million plant specimens in the Philecology Herbarium at BRIT. It’s a nice, big, round number, and it sounds cool when tour groups come through. What if I told you that as imposing as that number sounds, the real number is closer to a thousand billion (1,000,000,000,000) plants*? The goal of an herbarium is to preserve plants. The ideal specimen, in many respects, has all the essential...
Read More >

The Living Herbarium: Many Hands Make Godzilla

Article originally published in The Leaflet (May 2014) by Brian Witte, PhD, BRIT Research Associate There is a stereotype of the scientist as a lone genius, laboring in obscurity until their “Eureka!” moment changes the world. If Hollywood is to be believed, this Eureka moment is usually followed by the destruction of Tokyo and/or New York by a giant robot/genetic mutant/superstorm. In reality, we have a tragic lack of giant robots, and nothing that we’ve done in the herbarium has (yet) threatened a major metropolitan area. We also rely heavily on collaboration, rather than solitary toil. In fact, I would venture to say that collaboration is the fundamental characteristic of science. NOT what we do…exactly. Nowhere is this more on display than in the herbarium at BRIT. Over the past month,...
Read More >

The Sweep of Time

Article originally submitted for The Leaflet (June 2014) by Brian Witte, PhD, BRIT Research Associate Most of us live in the moment. Paycheck-to-paycheck, living for the weekend, summer vacation, twitter updates. Updates now are measured in seconds. America, too, is a young nation. Few places west of the Appalachians boast buildings over 150 years old, and most of us live in suburbs built in the decades following World War II. So much around us is new…even our landscapes are new, transformed by mechanized farming, car culture, and introduced species. That’s not entirely news, and it’s not entirely new, either. Look, for example, at this sheet I recently encountered while tidying up a database of digitized herbarium specimens. Click to enlarge and read labels. This was one of the last colle...
Read More >

Insert Clever Title Here

“Hell — is sitting on a hot stone reading your own scientific publications.” ~ Erik Ursin, fish biologist. One of my favorite journal articles is a little number called “How to write consistently boring scientific literature." Penned by Kaj Sand-Jensen at the University of Copenhagen, this piece is a glib editorial about technical writing…that was somehow published and promulgated by a technical writing source. (Brilliant!)
Read More >