Morning glory or pole bean plant?

(Question)

We grow pole beans annually, but this year, as I pull away the morning glory plants, I’m not sure I’m removing the right plant.

How do you distinguish the morning glory plant versus the pole bean plant?

I’d like to remove the morning glory plant.

(Answer)

Thanks for your inquiry.  It can be very difficult to identify similar looking plants.  I am assuming the vines have not bloomed and the fruit has not appeared.  I would suggest you take a close look at the leaves and stems.  I have prepared a chart comparing some of the common characteristics to see where the two plants differ.  Morning Glory leaves are simple and Pole beans are pinnately compound.  I have attached a link to the University of Colorado which describes both leaf types.

Leaflet Arrangement on Petiole

  • Simple – Leaf blade is one continuous unit (cherry, maple, and elm)
  • Compound – Several leaflets arise from the same petiole
  • Pinnately compound – Leaflets arranged on both sides of a common rachis (leaf stalk), like a feather (mountain ash)
  • Palmately compound – Leaflets radiate from one central point (Ohio buckeye and horse chestnut)
  • Double pinnately compound – Double set of compound leaflets

Note:  Sometimes identifying a “leaf” or “leaflet” can be confusing.  Look at the petiole attachment.  A leaf petiole attaches to the stem at a bud node.  There is no bud node where leaflets attach to the petiole.
https://www.ext.colostate.edu/mg/gardennots/153.html

For further information on these plants please refer to:

Ipomoea purpurea (Morning Glory) https://gobotany.newenglandwild.org/species/ipomoea/purpurea/

Phaseolus vulgaris (Pole beans) https://gobotany.newenglandwild.org/species/phaseolus/vulgaris/

Characteristic Morning Glory Pole beans
LEAF:
Leaf type simple Pinnately compound
Leaf arrangement alternate alternate
Leaf blade edges Entire ( has no teeth or lopes) entire
Hairs on underside of leaf is fuzzy or hairy Is fuzzy or hairy
Hairs on upper side of leaf Is fuzzy or hairy Is fuzzy or hairy
Hooked Hairs on underside of leaf No yes
Hairs on Leaf stock The petiole has hairs on it No hairs on petiole
Leaf vein pattern the major veins radiate out from one   point at the base the secondary veins branch off at   intervals from the primary vein
Leaf tip the tip of the leaf blade is acuminate (tapers to a long, thin point)the tip of the leaf blade is acute (sharply pointed)

 

the tip of the leaf blade is acuminate (tapers to a   long, thin point)
Leaf blade base shape cordate   (heart-shaped, has rounded lobes at the base)
STEMS:
Direction of stem hairs Upwards to outwards Not stated
Hair between stem nodes Yes Yes
Stem succulence no
Tendrils no No