ID Characteristics
This plant is in the Boraginaceae - the borage family. Previously it was placed in the Hydrophyllaceae (waterleaf family), which is now considered to be a subfamily in the Boraginaceae.
Desert bluebells grow from a small clump of leaves less than a foot wide. It can grow to 2 feet but in our area is typically less than a foot high.
The initial leaves are basal, 3-4 inches long with a petiole covered with glandular hairs. The blade is rounded with a coarsely toothed edge. The petiole is red and the edges of the leaves are often tinted red. The leaves on the flower stalk are smaller and arranged alternately.
Each coiled flower stalk has numerous flowers and glandular hairs. The flowers are held on one side of the coiled stalk that gradually unrolls as new flowers begin to open, a structure known as a helicoid cyme. This structure can be seen in the above photo, just below the right-most flower.
The flower petals of desert bluebells are a deep blue fading to purple. The deep blue color and the size of the flowers differentiates this plant from other species of Phacelia found in Arizona. The petals are fused at the base, separating into 5 lobes at the opening. Each flower is 1 inch wide and about 1.5 inches long and bell-shaped. The 5 short, narrow sepals and the flower stalk are red and covered with glandular hairs, the source of the chemical that causes contact dermatitis in some people. Both stamens and style are longer than the petals.
The fruit is inconspicuous, just slightly longer than the sepals, about half an inch long. The style, which is split in two for about half its length, may stay attached to the fruit.