Native Plants

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Wednesday - January 19, 2011

From: Coppell, TX
Region: Southwest
Topic: Plant Identification
Title: Identification of tall dry, stalk plant in Central Texas
Answered by: Nan Hampton

QUESTION:

I'm trying to identify a plant from my childhood in Central Texas, as I'd like to evaluate its potential as a biofuel crop. It is a stalk-plant, growing quite tall, 7-8' on average, with knobbed joints every 1.5-2', and smaller stalky branches from the main. In the vegetative state, it emitted a pungent odor especially when crushed, as well as a sticky white sap. Would it be a Sweet Clover? It looks quite similar, but I'm unsure if there are other similar species that it could be. It grew densely beside a friend's house by a corn field, a very unkempt area. There was literally a forest of these stalks, again very tall. During the dry season, we would use them as staffs and play-swords, as they'd pull up easily, and the branches would snap right off leaving just the main, now woody stalk. Inside, when dry, the white substance had hardened into an interior foam-like pulp. Thanks!

ANSWER:

This particular Mr. Smarty Plants keeps thinking she should know this plant—having been a Central Texas resident interested in native plants for a VERY long time. I even consulted with other longtime Central Texas residents, but we haven't been able to come up with anything definitive. Here are several suggestions that have some, but not all, the features you describe:

Cicuta maculata (Spotted water hemlock) or Conicum maclatum (hemlock) (non-native European plant) that can both grow as tall as you describe, are pungent, and have sticky sap. Additionally, both are highly toxic (check them out by their scientific names in the Poisonous Plants of North Carolina). They both prefer damp places, however, and you probably wouldn't have played with the living green stalks very much without becoming very ill.

Heterotheca subaxillaris (Camphor weed) is certainly sticky and aromatic but the tallest I can find reference to is 5 feet and I don't believe it would have nodes/joints. It does grow in disturbed areas.

Laennecia coulteri (Conyza) is a tall-ish (4.5 to 5 feet) that grows in disturbed areas, but I haven't found any reference to sticky sap or pungent scent and has no nodes/joints as far as I can tell. Here are more photos and information.

Melilotus officinalis (yellow sweetclover) or Melilotus alba (white sweetclover) are certainly candidates. They were introduced as a forage plant and are now valued by beekeepers. They are, however, non-native and considered an invasive species. Both grow very tall and are high in coumarin which would make them aromatic. I couldn't find any information about their sap and can't really see that there are nodes/joints on the stem. Here are photos and more information.