456 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
The Organ Mountains plants are probably the subspecies cylindricus Engelm. 
and subspecies tubulosus Coulter, which are nothing but growth forms. The 
northern plants are usually much smaller. 
3. Echinocereus dasyacanthus Engelm. in Wisliz. Mem. North. Mex. 100. 1848. 
Cereus dasyacanthus Engelm. Mem. Amer. Acad. n. ser. 4: 50. 1849. 
Type Locatiry: ‘‘El Paso del Norte [now Ciudad Judrez],’’ Chihuahua. 
Ranae: Southern Arizona to trans-Pecos Texas and adjacent Mexico. 
New Mexico; Queen; mesa 10 miles west of Carlsbad. Lower and Upper Sono- 
ran zones. 
4. Echinocereus pectinatus (Scheidw.) Engelm. in Wisliz. Mem. North. Mex. 110. 
1848. 
Echinocactus pectinatus Scheidw. Bull. Acad. Sci. Brux. 5: 492. 1838. 
Cereus pectinatus Engelm. in A. Gray, Mem. Amer. Acad. n. ser. 4: 50. 1849. 
Type Locauity: ‘Habitat prope lila del Pennaso in locis temperatis.”’ 
RanGe: Western Texas and southeastern New Mexico to Mexico. 
New Mexico: Knowles (Wooton). Lower Sonoran Zone. 
Our plant is not typical and may be incorrectly determined. It is smaller than the 
common forms of this species, being only 5 or 6 cm. high; the areoles are not so numer- 
ous nor so closely approximated as is common in that species; the flower is larger, 
opens only in daylight, and is purple. Further study of the species will be necessary 
for more accurate determination. 
5. Echinocereus rigidissimus (Engelm.) Rose, Contr. U. 8. Nat. Herb. 12: 293. 
1909. RAINBOW CACTUS, 
Cereus pectinatus rigidissimus Engelm. Proc. Amer. Acad. 3: 279. 1856. 
Type Locauity: ‘‘In the Sierras of Pimeria Alta in Sonora.’’ 
Rance: Western Texas to southern Arizona and adjacent Mexico. 
New Mexico: Deer Creek; Hatchet Ranch; near White Water; Dog Spring. 
Lower and Upper Sonoran zones, 
6. Echinocereus fendleri (Engelm.) Riimpl. in Férst. Handb. Cact. ed. 2. 801. 1886. 
Cereus fendleri Engelm. in A. Gray, Mem. Amer, Acad. n. ser. 4: 50. 1849. 
Cereus fendleri pauperculus Engelm, op. cit. 51, 
TYPE Locaity: Santa Fe, New Mexico. Type collected by Fendler. 
Rana@eE: Utah and Colorado to western Texas and northern Mexico. 
New Mexico: Albuquerque; Fort Defiance; San Mateo Peak; Apache Mountains; 
Socorro; Mangas Springs; Steins Pass; Hermosa; Hillsboro; Graham; Cooks Peak; 
Organ Mountains; Farmington; Carrizo Mountains. Plains and mesas, chiefly in the 
Upper Sonoran Zone. 
7. Echinocereus stramineus (Engelm.) Riimpl. in Férst. Handb. Cact. ed. 2. 797. 
1886. 
Cereus stramineus Engelm. Proc. Amer. Acad. 8: 282. 1856. 
Type Locatiry: ‘Mountain slopes, from El] Paso to the Pecos and Gila Rivers,”’ 
Texas and New Mexico. 
Rance: Trans-Pecos Texas to southern Arizona and adjacent Mexico. 
New Mexico: Tortugas Mountain. Lower Sonoran Zone, usually on limestone soil, 
8. Echinocereus gonacanthus (Engelm. & Bigel.) Lem. Cact. Hort. Monv. 57. 1868. 
Cereus gonacanthus Engelm. & Bigel. Proc. Amer. Acad. 3: 283. 1856. 
Type Locauity: Near Zuni, New Mexico. Type collected by Bigelow. 
Rance: Southern Colorado and northern New Mexico. 
New Mexico: Twenty-five miles north of Gallup; south of Zuni Reservation; 
White Sands. Upper Sonoran Zone. 
