Ask Mr. Smarty Plants

Mr. Smarty Plants has thought a lot about your plant, consulted with others and tried to think what it could be.   Unfortunately, we found your description of it a bit confusing and, thus, don't feel too confident of the suggestions made below.  

First of all, is it an annual that grows anew each spring?   Or, is it a perennial woody plant that continues to add height each year?  How large are the leaves?

If it is an annual, here are a few suggestions with leaves that look something like my understanding of your description:

Ambrosia trifida (Great ragweed) can grow 12 feet or more high.  Its leaves, as its name implies, have three lobes not five.  It tends to grow in disturbed areas with many plants growing together.  It is a native plant found growing in Ellis County.  Here are photos from our Image Gallery:

Ambrosia trifida var. texana

Ricinus communis (Castor bean) is a semi-woody plant that can grow to 40 feet in frost-free climates.  In Ellis County it would be an annual, however, that can grow as high as 15 feet in one season.  Its leaves are palmate with 5 to 11 lobes.  It is an invasive non-native from Africa and the Middle East and all parts of it are poisonous. 

Abelmoschus esculentus, okra is a non-native plant that is grown in vegetable gardens to a height of 8 feet.  Its leaves are palmate with multiple lobes.  Its leaves are rough, but its flower is not as you described—it is a showy flower in the hibiscus family.  Here are more photos.

Here are semi-woody and woody plants that have leaves that look somewhat like the leaves you describe:

Firmiana simplex (Chinese parasol tree) is a non-native invasive species from Asia with multi-lobed leaves (three to five, usually).  It can grow as high as 50 feet.   Here are more photos and information.

Both the native Morus rubra (Red mulberry) and the non-native Morus alba (White mulberry) have variably-shaped leaves, some with multiple lobes.

Ficus carica, (fig) also has variably-lobed leaves. 

If none of the plants suggested are the plants you are seeing (and I fear they aren't), I suggest you visit our Plant Identification page to find links to several plant identification forums that might be able to identify your mystery plant.  If you have, or can take, a photo of the plant, you can submit it to one of the forums for identification.  You might also consider contacting your Ellis County Texas AgriLife Extension Office Agent or someone in the Dallas Chapter of the Native Plant Society of Texas (NPSOT) to see if they can help you identify the plant.