PACHYCEREUS. 



73 



by dense masses of brownish wool; areolcs approximate or even conniicnt; radial spines about 12 

 slender; centrals 3, i very long, sometimes 12 to 13 cm. long; flowers borne near the tops of the stems 

 or branches, 6 to 7 cm. long; the bud, afterwards the flower, and finally the fruit, completely con- 

 cealed m the long wool ; ovary covered with small, pale, imbricated scales ; flower-tube also covered 

 with imbricated scales, but these larger and pinkish, pointed; flowers doubtless opening at night, but 

 still expanded at 8 o'clock in the morning; tube proper 10 mm. long or less; throat funnelform, 3 cm. 

 long; inner perianth-segments numerous, 1.5 to 3 cm. long, cream-colored; inner perianth-segments 

 and stamens inflexed after anthesis, with the stiff outer perianth-segments pressed down upon them ; 

 stamens attached all over the throat, the innermost and lower row united at base and appresscd 

 against the style; filaments cream-colored; style stout, stiff, 7.5 cm. long, cream-colored; stigma- 

 lobes linear, erect, cream-colored. 



Fig. 107. — Pachycereus chrysomallus 



Type locality: Mexico. 



Distribution: Puebla and Oaxaca, Mexico. 



This is one of the characteristic plants on the mesas around Tehuacan. When 



large plant with many u] 

 makine it very difficult 



In 1906 Dr. 



MacD 



from 



Hort 



1845) and Pilocereus mill tan's (Salm- 



k, Cact. Hort 



Illustrations: 



I 



850, as synonym) probably belong here. 



Mag. 21: 699, as Pilocereus fulvicep 



MacDougal 



Plate XI illustrates the top of a flowering plant in the New York Botanical Garden 

 eht from Tehuacan. Mexico, by Dr. MacDougal and Dr. Rose in 1906. Figure 107 is 



from 



of this plant ; and figure 1 09 a longitudinal section of the flower 





