154 
COMPOSITAE 
4. D. concolor Greene. Nearly simple or branched from the base, 2.4 
to 9.6 cm. high; flowers 8 to 9 mm. broad; corolla blue, the lower lip 
with a velvety quadrate spot; 
stamen-column included. — Abund¬ 
ant locally in low places. 
COMPOSITAE 
SUNFLOWER FAMILY 
Herbs or shrubs. Flowers col¬ 
lected in a head surrounded by 1 to 
several rows of bracts (involucre), 
the marginal flowers (rays) fre¬ 
quently with strap-shaped and very 
conspicous corollas, the inner 
flowers (forming the disk) with 
tubular 5-toothed corollas, or some¬ 
times all the flowers with strap- 
cOrollas. Calyx in the form of 
hairs, bristles, scales or teeth. Sta¬ 
mens 5. united by their anthers. 
Style 2-cleft at apex. Ovary in¬ 
ferior, 1-celled, becoming a dry 
achene.—This family, with about 
12,000 species distributed all over 
the earth but most numerous in 
temperate climes, is the second 
largest family of flowering plants, 
being exceeded only by Orchi- 
daceae. It vastly exceeds Orchi- 
daceae, however, in number of in¬ 
dividuals. The family contains 
plants which yield fats, oils, tan¬ 
nins and medicinal drugs, but is 
not very important economically. 
It furnishes a large number of 
agricultural pests which are espec¬ 
ially hard to combat on account c 
sess for effective seed dispersal. 
Fig. 7. A typical flower head of Com- 
positae. To the beginner a flower 
head in this family looks like a single 
flower, but on examination it is seen 
to consist of a large number of 
flowers closely packed -together as 
shown in the above illustration of 
California Sunflower, Helianthus cali- 
fornicus DC.; a, long. sect, of head 
x Y\ ; b, ray-flower x 1; c, disk- 
flower x 2^4 ; d, bract x 2V* ; e, 
achene and pappus (calyx) x 2 l /i. 
the means which Compositae pos- 
A. Plants without milky juice; disk-flowers without ligulate corollas. 
I. Style branches naked or prolonged into a flattened hairy or 
PUBESCENT APPENDAGE. 
Rays mostly present; pappus of awns or bristles ; .anthers blunt at the base ; style- 
branches appendaged ; herbage sometimes gummy or resinous; leaves 
alternate; receptacle naked; bracts of the involucre well imbricated; 
disk-flowers yellow.— Asterae (Aster Tribe). 
Rays present (sometimes inconspicuous) ; flowers yellow, white, lavender or 
purple : mostly herbs. 
Flowers of both disk and ray yellow. 
