314 



SCIENCE. 



[Vol. XXII. No. 566 



MesquHe XiMf. 

 About 3,800 to 4,800 feet. 



Characteristic plants. — Yucca baccata (Spanish bay- 

 onet — at its climax), Yucca angustifolia (narrow-leafed 

 yucca), Prosopis juliflora (mesquite), Larrea mexicana 

 (creosote bush), Opuntia lepticaulis (vine cactus), Opun- 

 tia arborescens — some (tree cactus). Ephedra nevadense 

 (clapweed), Opuntia spp. (smaller-leafed prickly pears), 

 Opuntia engelmanni — some (prickly pear), Echino- 

 cactus wislizeni (barrel cactus), Cereus spp. (bunch 

 cacti), Atriflex canescens (sage bush), Fallugia para- 

 doxa — some along arroyos, Fouquiera splendens (can- 

 dle wood), Krameria ' parvifolia, Zizyphus lycioides, 

 Baccharis angustifolia, Parkinsonia sp. (?), Acacia sp. 

 (cat's-claw thorn), Chilopsis saligna (along arroyos, and 

 especially near base of mountains), Perezia nana, cer- 

 tain grasses on plains to north (Jornada del Muerto), 

 etc. 



Dasylirion or Scrub Oak Zone. 

 About 4,800 to 6,800 feet. 



Characteristic plants. — Dasjdirion wheeleri (sotol), 

 Quercus undulata var. wrightii (scrub oak), Opuntia 



north at a point about a mile east of Mr. Isaac's place 

 (mostly south exposure) ; and also as noticed in general 

 in the whole range, on the western slopes, from Soledad 

 to the south end. As before said, the zones were more 

 particularly noted in the ascent to the ridge above the 

 Modoc mine, Nov. 12, 1892, as this is about the highest 

 accessible point in the range. 



On Nov. 26, 1892, an ascent was ir^ade to the top of 

 the ridge of the northeast portion of the range. The 

 results of this trip are detailed separately below. Going 

 up this slope, which has a north-northeast exposure, the 

 following seventeen characteristic species of vegetation 

 were noticed. The real ascent was begun at a point 

 about four or five miles a little east of south of San 

 Augustine. Exactly a year before this, I made an as- 

 cent nearly to the top of the higher portion of the same 

 ridge about two miles farther to the westward, on which 

 nian)^ of the same plants were also noted. 



Plants found on going up northeast slope of Organ 

 Mountains, Nov 26, 1892. — The vertical distance was 

 divided into approximate fifths, which are spoken of as 

 first to fifth belts. This vertical distance from the level 



Dl.\GR.'\M OF THE ORG.\N MOUNT.MNS IN SOUTHERN NEW MEXICO, 



1. Organ peak. 5. Old San Augustine hotel. 9. Riley's ranch. 



2. Organ pass. 6. Davies-Lecinbky ranch. 10. Modoc mine. 



3. Bayler pass. 7. Stephenson-Bennett mine. u. Soledad canon. 

 3. Sugar loaf. 8. Riley's well. iz. Isaac's ranch. 



Highest peaks (8,Soo ft.). 

 Highest part of ridge betw. peaki 

 Dip of ridge at north end. 

 Side canon opening into Soledad. 



17. Ridge of northeast part of rang 



18. South and wagon pass. 

 iq. Bishop's Cap. 



arborescens (tree cactus — at its climax). Yucca baccata 

 (Spanish bayonet), Accacia sp. (cat's-claw thorn), Opun- 

 tia engelmanni (prickl)' pear or tuna — at its climax). 

 Agave heteracantha (century plant), Agave parryi 

 (Parry's century plant), Unguadia speciosa (Mexican 

 buckeye), Celtis occidentalis (hackberry), Fraxinus sp. 

 (ash), Robinia neomexicana (New Mexico locust), Fal- 

 lugia paradoxa, etc. 



Juiiipe, 

 About t 



or Cedar Zone. 

 ,800 to 7,500 feet. 



Characteristic plants. — Juniperus sp. (cedar), Cerco- 

 carpus parvifolius (mountain mahogany), Garrya 

 wrightii, etc. 



Pine Zone. 

 About 7,500 to S,8oo feet. 



Characteristic plants. — Pinus edulis probably (pifion), 

 Pseudotsuga douglassii (Douglas spruce), Quercus un- 

 dulata var. gambellii (a scrub oak on top of ridge, 8,000 

 feet), Pinus ponderosa (Californian pine), etc. 



The above are the more important forms of vegeta- 

 tion met with in going up past the Modoc mine to the 

 top of the ridge (slope with western exposure) ; in going 

 up a long side cation which opens into Soledad on the 



at San Augustine to the top of the ridge is probably 

 about 2,000 feet, the ridge being, apparently, about 

 7,000 feet elevation at its eastern end. The lower range 

 of the hardier species, as shown below, is due to the 

 north or northeast exposure. 



1. Cat's-claw thorn (Acacia sp.). — Extending from 

 near base of mesa-like prolongation of north end of 

 range through first belt. 



2. Mulberry (Morus parvifolia). — Upper portion of 

 cat's-claw thorn area or first belt. 



Mexican buckeye (Unguadia speciosa). — Second 



belt 

 4- 



S- 



Wild grape (Vitis sp.). — Second belt. 

 Wild cherry (Cerasus sp.?). — Second belt. 



6. Maple (Acer sp.). — Second belt. 



7. Small bunch cacti (Cereus 2 spp.). — Third belt. 



8. Ash (Fraxinus pistacifolia). — Third belt. 



9. Hackberry (Celtis occidentalis). — Third belt. 



10. Willow (Salix sp.). — Third belt. 



11. Cottonwood (Populus sp. much resembling P. 

 fremontii). — Third belt. 



12. Scrub oak (Quercus undulata var. wrightii). — 

 Third and fourth belts. Often hung with mistletoe. 



13. Piiion (Pinus edulis?). — Large trees on lower ex- 



