A PARASITIC PLANT — THACKERY AND OILMAN 411 



from the center and ajrain dividing as the circumference is ap- 

 proached. Tliis formation seems to take place as the seed vessels 

 develop and may come from pressure of the growing capsules. The 

 edges of the flower head are curled under, and at maturity each ray, 

 in cases where the split occurs, resembles a scape with the persistent 

 flowers on the upper side. The first flowers open near the center, the 

 later ones toward the outside, until the last ones appear near the outer 

 edge. The rays into which (he inlloroscence ^^plits vary in width ac- 

 cording to the size of the disk or the number of the divisions. 



The flower heads, or disks, were from 11/2 to 5 inches in diameter 

 and about an inch or a little less in thickness. We found one head, 

 however, which measured 8 inches in diameter. The flowers form 

 a scattered circle around the center and in later openings, as stated, 

 approach the outside, thus forming successive irregular circles of 

 flowers. The flower is tubular in shape with a spread of about 

 one-eighth of an inch, and is about three-eighths of an inch in 

 length. The corolla lobes are from six to nine, or occasionally even 

 more, although G, 7, and 8 seem the most common numbers. The 

 flower is amparo purple and the throat a hortense violet color 

 (Ridgeway's Color Manual), and the margin is white. The filiform 

 sepals are light purple in color with numerous plumose silvery hairs 

 on the upper side which tend to mass or felt at the surface of the 

 flower head, making a soft, velvety surface. 



The capsule is shaped like a tiny flat onion, slightly larger than 

 an ordinary pinhead. When mature, it splits horizontally around 

 the equatorial circumference, disclosing a circle of tiny seeds, 

 usually 16 in number. These seeds are shaped like a segment of 

 a tangerine orange and are brown in color, with a rough or pitted 

 surface. As far as could be determined from an examination of our 

 specimens, seed matured from less than half of the flowers. The 

 base, or foundation of the disk, which might be called the receptacle, 

 was light purple and faded to a brown as the plant matured. By 

 soaking this colored substance in water, it appeared to us brown, 

 instead of the expected purple color. 



Much difiiculty was encountered in digging the plants because 

 fresh sand, which was dry most of the way dow^n, kept sliding back 

 into the hole almost as fast as it could be thrown out, so that in each 

 instance when the work was finally done, we had a funnel-shaped 

 hole, several feet across and usually from 3 to 5 feet in depth. To 

 add to the difficulty, the long fleshy stalks of the best specimens of 

 Ammobroma, usually from 1 to V/o inches in diameter, were so 

 tender and brittle that they had to be supported by one man while 

 the other did the digging. The stalks were whitish in color, sparsely 

 clothed with scales about an inch long and an eighth of an inch 

 wide, but as the stalks mature the scales take on a tan color. The 



