Herbs with alternate leaves. Flowers large, white or yellow. Stamens very numerous. Petals flat. Capsule 1-celled, straight; seeds few or many. Named in honour of Gr. Mentzel, a German botanist.

1. M. aurea (fig. 111), syn. Bavtonia aurea. - A very hand-some Californian annual, better known under the latter name.

Fig. 111. Mentzelia aurea. (1/4 nat. eize.)

It grows about 2 feet high, with whitish branches, hispid leaves, and bright yellow flowers.

2. M. bartonioides, syn. Eucnide and Microsperma. - Very near the preceding, but with smaller yellow flowers.