284 THE CACTACEAE. 
about 20 cm.; outer perianth-segments linear, pointed, reddish brown, the inner perianth-segments 
narrowly lanceolate, 7 cm. long, 12 to 15 mm. broad, acute; filaments numerous, weak, white; style 
long and slender, exserted beyond the withering perianth; stigma-lobes slender, white, entire; 
scales on the ovary and flower-tube minute, 1 to 1.5 mm. long, reddish brown, bearing white felt 
and white bristles in their axils; fruit crowned by the withering perianth, globular, 2 to 2.5 cm. in 
diameter, reddish, bearing numerous, small, circular areoles, these with clusters of acicular spines 
sometimes 1 cm. long. 
Type locality: Southern Mexico. 
Distribution: Mexico, but range not known. 
We have had this plant under observation since 1914 when cuttings were sent us 
by C. Z. Nelson, an enthusiastic grower of cacti at Galesburg, Illinois, who obtained it 
from southern Mexico from Dr. J. L. Slater. This plant made two flowers during the week 
of May 17, 1922; the fruit ripens very slowly and did not mature until October 10, 1922. 
According to Wilhelm Weingart, the same species has long been grown by Frantz 
de Laet at Contich, Belgium, also from Mexican material. 
Illustration: Zeitschrift Sukkulentenk. 1: 33, as Cereus nelsontt. 
Figure 261 shows a branch bearing a newly matured fruit. 
Fic. 261.—Selenicereus nelsonii. 
On page 216, vol. 11, under Werckleocereus tonduzii, add: Illustration: Monatsschr. 
Kakteenk. 31: 85, as Cereus tonduzii. 
On page 218, vol. 11, under A porocactus leptophis, add to illustrations: Ann. Fl. Pom. 
1839: pl. 43, as Cereus leptophis. 
On page 219, vol. 1, under Aporocactus flagelliformis, add to illustrations: Tribune 
Hort. 1: pl. 4, as Cereus serpentinus ; Fl. Antill. 1: pl. 67, as cierge queue de souris; Cact. 
Journ. 1: 82; Rother, Praktischer Leitfaden Kakteen 57; Remark, Kakteenfreund 6; 
Watson, Cact at ed. 3. f. 11; Floralia 42: 371; Gartenwelt 15: 637; Blanc, Cacti 27. 
0. 104, Amer. Gard. II: 527 as Cereus flagelliformis; Cact. Journ. 1: 125; 2: 34} 2: 153) 
as C. flagelliformis cristatus. J 53 2+ 34 53 
Insert: Cereus smithianus is a hybrid listed by Sweet (Hort. Brit. ed. 2. 237. 1830) 
which the Index Kewensis refers to C. smithii, a generic hybrid already referred to. 
On page 221, vol. 11, under A porocactus martianus, add to the illustrations: Thomas, 
Zimmerkultur Kakteen 14, as Cereus martianus. 
