164 ''''US CACTACHAK. 



referring it to Cereus, asks if it may not be an Opmitia. In the original description the 

 areoles are described as 6-anglcd, which suggests a cylindric Opuntia with angled tubercles 

 rather than areoles. 



28. CARNEGIEA Britton and Rose, Journ. N. Y. Bot. Card. 9: 187. 1908. 



A large, columnar cactus with stout, erect, many-ribbed stems and branches, the areoles felted 

 and spiny, the spines of flowering and sterile areoles different; flowers borne singly at the uppermost 

 ari-ok-s, diurnal, funnelform-campanulate, the stout tube nearly cylindric, expanded above into the 

 throat; scales on tube few, broadly ovate to oblong, acute, bearing small tufts of felt in their axils; 

 inner perianth-segments white, short, widely spreading or somewhat reflexed when fully expanded; 

 ovary oblong, covered with scales similar to those of the tube; stamens very numerous,* about three- 

 fourths as long as the inner perianth-segments; stigma-lobes 12 to 18, narrowly linear, reaching a 

 little above the stamens; fruit an oblong, ellipsoid, or somewhat obovoid berry splitting down from 

 the top into 2 or 3 sections, containing red pulp and bearing small distinct ovate scales, its areoles 

 spineless or bearing a few short spines; seeds small, very numerous, black and shining; embryo 

 hooked; cotyledons incumbent; endosperm wanting. 



A monotypic genus of the southwestern United States and Sonora. It is dedicated to 

 Andrew Carnegie (1835-1919), distinguished philanthropist and patron of science. 



1. Carnegiea gigantea (Engelmann) Britton and Rose, Journ. N. Y. Bot. Gard. 9: 188. 1908. 



Cereus giganteus Engelmann in Emory, Mil. Reconn. 159. 1848.! 

 Pilocereus engelmannii Lemaire, Illustr. Hort. Q: Misc. 97. 1862. 

 Pilocereus giganteus Riimpler in Forster, Hand. Cact. ed. 2. 662. 1885. 



Stem simple and upright, up to 12 meters high, or with one or two lateral branches, or some- 

 times with 8 to 12 branches, the branches 3 to 6.5 dm. in diameter; ribs 12 to 24, obtuse, i to 3 cm. 

 high; areoles about 2.5 cm. apart or nearly contiguous on the upper part of the plant, densely brown- 

 felted; spines of two kinds, those at the top of flowering plants acicular, yellowish brown, porrect, 

 those of sterile plants and on the lower parts of flowering plants more or less subulate, the central 

 ones stouter than the radials, often 7 cm. long; flowers 10 to 12 cm. long, sometimes nearly as broad 

 as long when fully expanded; tube about 1.5 cm. long, green, its scales broad and short, white-felted 

 in their axils; throat about 3 cm. long, covered with numerous white stamens; style stout, 5 to 6 

 cm. long, white or cream-colored; ovary somewhat tuberculate, bearing scales with woolly axils; 

 ovules numerous; berry red or purple, obtuse, 6 to 9 cm. long, edible, its few, distant scales ovate, 

 2 to 4 mm. long, with or without i to 3 short acicular spines in their axils. 



Type locality: Along the Gila River, Arizona. 



Distribution: Arizona, southeastern California, and Sonora, Mexico. 



The size of the giant cactus is usually overestimated, for it is generally stated to be 

 from 15 to 24.4 meters high, while the tallest plants actually measured are not over 12 

 meters high. Dr. MacDougal reports weighing a plant which was approximately 5.5 meters 

 high, which weighed nearly 770 kilograms. There are a number of Mexican and South 

 American species which are taller and which would weigh more than Carnegiea gigantea: 

 Lemaireocereus weberi must be many times heavier. 



Although this species was not described until 1848, it seems to have been known to the 

 early missionaries in California and Mexico (about 1540). It is referred to by Humboldt, 

 according to Engelmann, in his work on New Spain (2: 225). According to Dr. Mac- 

 Dougal, the first Anglo-Saxon observation of Carnegiea gigantea was made by J. O. Pattee 

 in 1825. 



* Dr. Charles E. Bessey (Science n. s. 40: 680. 1914) reports that he had the stamens in one flower counted, and 

 found that there were 3,482, while one ovary contained 1,980 ovules. 



t It is usually stated that this species was published on page 158, this even being the reference given by Engelmann 

 himself. Emory's report, in which this species was described, was printed at least twice the same year and about 

 tin same date, once as a Senate Document (Executive Document No. 7) and once as a House Document (Executive 

 Document No. 41). In the former Cereus gi^intcus occurs on page 159 and in the latter on page 158. There has 

 been considerable speculation and much difference of opinion as to which edition was published first, but we have 

 recently come into possession of Emory's personal copy of the Senate Document No. 7 marked "with manuscript 

 corrections by the author." From this copy the type of the other edition was set up. 



