Late in the fall you may hear the rich tone of a Bombilius, one of the commonest flies seen about flowers, as he darts rapidly among the white asters. Unless you have been initiated, you may mistake this fly for a bee. He sings a very similar song and wears a similar dress; but he is not a very good imitation, after all, and a little familiarity with him will give you courage to catch him in your hand if you are quick enough, for he is incapable of stinging or biting: he can merely make a noise out of all proportion to his size. He is simply living from hour to hour, and lays up no store for the winter, enjoying more or less security from his resemblance to the industrious and dangerous insect which he imitates. DAISY FLEABANE; SWEET SCABIOUS (Erigeron annus) Thistle family Flower-heads - Numerous, daisy-like, about 1/2 in. across; from 40 to 70 long, fine, white rays (or purple- or pink-tinged), arranged around yellow disk florets in a rough, hemispheric cup whose bracts overlap. Stem: Erect, to 4 ft. high, branching above, with spreading, rough hairs. Leaves: Thin, lower ones ovate, coarsely toothed, petioled; upper ones sessile, becoming smaller, lance-shaped. Preferred Habitat: Fields, wasteland, roadsides. Flowering Season: May-November. Distribution: Nova Scotia to Virginia, westward to Missouri. At a glance one knows this flower to be akin to Robin's plantain (q.v.) the the asters and daisy. A smaller, more delicate species, with mostly entire leaves and appressed hairs (E. ramosus; E. strigosum of Gray) has a similar range and season of bloom. Both soon grow hoary-headed after they have been fertilized by countless insects crawling over them (Erigeron = early old). That either of these plants, or the pinkish, small-flowered, strong-scented SALT-MARSH FLEABANE (Pluchea camphorata), drive away fleas, is believed only by those who have not used them dried, reduced to powder, and sprinkled in kennels, from which, however, they have been known to drive away dogs. GROUNDSEL-BUSH or -TREE; PENCIL-TREE (Baccharis halimifolia) Thistle family Flower-heads: White or yellowish tubular florets, 1 to 5 in peduncled clusters. Staminate and pistillate clusters on different shrubs; the former almost round at first, the latter conspicuous only when seeding; then their pappus is white, and about 1/3 in. long. Stem: A smooth, branching shrub, 3 to 10 ft. high. Leaves: Thick, lower ones ovate to wedge-shaped, coarsely angular-toothed; upper ones smaller, few-toothed or entire. Preferred Habitat: Salt marshes, tidewater streams, often far from the coast. Flowering Season: September-November Distribution: The Atlantic and Gulf coasts from Maine to Texas.