46 COMPOSITE. 



Sherardia arvensis, Lian., an introduced weed, called in England Field Madder, 

 has been found at Berkeley by Professor Greene. A small annual, about 6 inches high, 

 bearing leaves in whorls of 6: flowers small, blue or pink, in little terminal heads sur- 

 rounded by a broad, deeply lobed involucre. 



GALIUM. 



G. spurium, Linn. Distinguished from G. aparine by pale green flowers and 

 pedicels recurved in fruit. 



G. Anglicuxn, Huds. Distinguished from these by greenish flowers followed by 

 fruit, not rough, with hooked hairs. All three introduced from the Old World. 

 Perhaps better considered varieties of G. Aparine. 



VALERIANACEJE. 



Herbs with opposite leaves, no stipules: the distinct stamens fewer than the lobes of 

 the corolla, and borne on its tube: the inferior ovary with two empty cells, and one con- 

 taining a solitary ovule, ripening into a kind of akene. Key to genera and species, 

 p. 133. 



DIPS AC ACE JE. 



Herbs with opposite leaves and flowers in dense involucrate heads, each flower 

 inclosed in a tubular in volucel, and subtended by a bract. Calyx adherent to the ovary: 

 corolla 4-5 lobed, bearing stamens alternate with the lobes: fruit crowned with the calyx 

 limb, 1 seeded. Key to genera and species, p. 134. 



Scabiosa atropurpurea, Linn., has run wild in some localities. It may be known 

 by its pinnate leaves and heads of black-purple or lighter colored flowers, even white, 

 the outer circles larger, and the calyx in fruit stem-like above the akenes, with 5 

 spreading bristle-like lobes. Commonly called Mourning Bride. 



COMPOSITES. 



Flowers, usually many in a dense head, sessile, on a common receptacle, surrounded 

 by a calyx-like involucre: the calyx reduced to hairs or scales, or obsolete: the corolla 

 tubular, equally lobed, ligulate or bilabiate, the 5 stamens united by their anthers into 

 a tube inclosing the 2-parted style: the ovary inferior, forming in fruit an akene which 

 is usually crowned with the persistent calyx (pappus). 



Sunflowers, marigolds, thistles, and dandelions are types of the conspicuous plants 

 in this order. This, the largest of all the orders, is represented in California by over 

 500 species. Although the flower heads are frequently large, the separate flowers, with 



