Uh Oh, Plant Families: Brassicaceae and Bromliaceae

Last year, during the slow dark months of winter, I wrote about plant families. It wasn't a pretty sight. Readers gnawed off legs for boredom. Eyedrop sales soared. Optometrists were inexplicably busy.

The suicide rate among dentists, sadly, remained steady.

Well, we are sinking into those slow dark months of winter once again, when things are not dead, only resting, and listless though I am, uninspired and feeling a bit like a dentist, I must press on. Given that, the circumstances of this cold, dark season, I give you more plant families.

Let's start with something peppery, the Mustard Family (Brassicaceae or Cruciferae).

There are about 3,200 species in the Mustard Family, in about 375 genera. They are found primarily in the cooler regions of Northern Hemisphere. Some are spat-upon weeds, some are poisonous to livestock, and some are valued as vegetables, spices and ornamentals. Many have peppery sap.

Flowers in this family are usually radially symmetrical, and grow in racemes. The 4 sepals and the 4 petals are often long and slender. There are typically 6 stamens with the outer 2 shorter than the inner 4. All these parts are attached at the base of the ovary.

Leaves are usually simple, sometimes pinnately divided. The fruit is a pod, either long and narrow, or short and broad.

Species found in eastern North America include Common Winter Cress (Barbarea vulgaris), Black Mustard (Brassica nigra), Cut-leaved Toothwort (Dentaria laciniata) and Peppergrass (Lepidium virginicum). Further west you might find Shortpod Mustard (Brassica geniculata), Tower Mustard (Arabis glabra), Spectacle Pod (Dithyrea californica), and Mountain Jewel Flower (Streptanthus tortuosus).

And then there's the Pineapple Family (Bromliaceae), which allows us to unpack, dust off, spit-shine and use the word epiphytic.

This family has about 1,300 species in fewer than 60 genera, most of which occur in tropical America. They are epiphytic herbs - an air plant growing on another plant, but taking no nourishment from it - usually with long stiff leaves and flowers. The flowers often have conspicuously colorful bracts. The leaves frequently have spiny margins and bases that sheath the stem. The fruit is a berry or capsule.

The flowers, often bilaterally symmetrical, have 3 sepals, 3 petals and 6 stamens. All are attached at either the base or the top of the ovary.

Perhaps the best known member of this family is Spanish Moss (Tillandsia usneoides), draped from the branches of Live Oak trees like a wizard's beard. This south-southeastern plant is not, as many might think, a parasite. While the scales of the plant do absorb water and nutrients from minerals leached from the foliage of the host tree, Spanish Moss is, yep, epiphytic. It photosynthesizes its own energy from the sun.

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