By: Steve Stocking, Education Chair, Sierra Club Delta-Sierra Chapter, 7/12/2010

It has been a glorious spring here between 1,000 and 3,000feet in the Sierra foothills. Farewell to spring has been widespread and abundant but is not the only wildflower to give us notice that summer has begun. By the 4th of July weekend most of us are thinking about field trips to the high Sierra. This year with the late snow and cool spring some native plant enthusiasts are staying down low longer while others are finding wildflowers between melting snow banks. Some of us who remain at the lower elevations are appreciating the flowers still blooming as the hills turn brown.

Why do some plants wait until summer to flower? At least some of these are what are called “long day plants”. These initiate flower when the nights are 10 hours long or shorter. They flower before the short day plants which flower during the july-September period. It is the dark period length which is critical. There are lots of other “day neutral plants” which flower not in response to day length but to temperature, stage of maturity or a combination of factors. Got that? You could check a “Plant Biology” text to learn more about photoperiodism. One long day plant flowering along roadsides in early summer is manyflower tobacco (Nicotiana acuminata). All species of tobacco plants contain several quite harmful toxins and should not be eaten nor smoked.

Another of the roadside plants flowering in early summer is moth mullein (Verbascum blattaria). This native of Eurasia has been used medicinally and as a garden ornamental. The flower color, genetically controlled, is most commonly yellow but some populations are white or purple flowered. White flowered wild carrot (Daucus carota) is often called “Queen Ann’s Lace and is closely related to the cultivated carrot. It came here from Eurasia as a garden vegetable. Fennel (Foeniculum vulgare) is also found in roadside areas and its foilage is used as a vegetable and its seeds for flavoring. Some people cal this plant anise. Mexican whorled milkweed (Asclepias fascicularium) found in similar areas. It is one of the food plants for Monarch butterfly larvae. The chemicals that the larvae get from the plant protect them form predators. All milkweeds are highly toxic to many animals including humans, horses and chickens.

The common sunflower (Helianthus annuus) also flowers in summer. It is a native wild type of the cultivated sunflower. The seeds are excellent food for small birds. Other members of the sunflower family flowering in summer are telegraph plant (Heterotheca grandiflora), common madia (Madia elegans) and virgate tarweed (Holocarpha virgata). The tarweed turns some fields yellow when the grass dries. It makes some areas of rangeland unpalatable to livestock but it does produce edible seed for wildlife and its pollen is an important food for bees. St. Johnswort or Klamathweed, (Hypericum perforatum) is the “poster plant” for biological control. Several introduced beetles have greatly reduced this troublesome plant. But what remains is toxic to livestock, particularly those with light colored skin. Other plants still flowring at these lower elevations include toyon ( Heteromeles arbutifolia), bush monkey flower (Mimulus aurantiacus), and buckeye (Aesculus californica). As the hills turn brown, the temperatures rise and the streams and rivers drop we still have these flowering plants to remind us that much of the vegetation is not dead but “resting” and waiting for another glorious spring.