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CATALOGUE OF SPECIES. 107 



This interesting species was well characterized by Dr. Gray, but it was afterwards 

 referred 1 to Petalonyx nitidus of Watson. It is conspicuously different from that 

 species, however, in its crenate leaves, its really shrubby character, and its simple 

 racemose inflorescence. P. nitidus is merely suffrutescent and has sinuate-dentate 

 leaves, and paniculate inflorescence. Several other less conspicuous but crucial char- 

 acters distinguish the two species. Dr. Parry collected the plant near St. George, 

 Utah, "within a stone's throw of the great Mormon temple,"- and, although he 

 searched the locality carefully, found but a single shrub. It has not been reported 

 since. From our specimens and Dr. Parry's, the following diagnostic description is 

 drawn: a shrub 0.8 to 1.5 meters high; branches of the year short, not exceeding 10 

 cm.; leaves ovate, sessile, crenate, bluntly acute, rounded or broadly cunate at the 

 base, 1.5 to 2.5 cm. long, the lower becoming small, oblong, narrowly cuncate, obtuse, 

 and entire; inflorescence a usually simple, spike-like, dense raceme; bracts ovate, 

 denticulate, long-acuminate; ovary 2 mm. long; calyx lobes filiform-linear, about 

 twice as long as the ovary; corolla 10 mm., its tube about 6 mm., in length. 



Our specimens were collected in the Vegas Wash, Nevada (No, 1901), about 150 

 kilometers from the type locality. 



Petalonyx thurberi Gray, PI. Thurb. 319 (1854). Type locality, "valley of 

 the Rio Gila." 



This plant varies widely in its leaves, some of them being entire, others irregu- 

 larly dentate. On a, single plant they are usually, however, uniform. The stems 

 are inclined to live over the winter, and often some growth is made during these 

 months. From these causes the plant presents a great variety of forms. It is dis- 

 tinguished from V, nitidus hy its sessile leaves, those of the branches being always 

 small and uniform, and by its inflorescence of simple, spikelike, in fruit usually 

 elongated, racemes terminating the branches. It was seen between Stoddard Wells 

 and Daggett (No. 135); in the south end of the Funeral Mountains, near Saratoga 

 Springs (No. 249); in the sandhills west of Watkin's rauch, Ash Meadows; and in 

 Furnace Creek Canon (No. 356). 



Mentzelia albicaulis (Hook.) Fl. Bor. Amer. i. 222 (1834), under Bartonia — 

 Dongl.MS.; Torr. & Gr. Fl. i. 534 (1840)— Dougl. MS. Type locality, "arid sandy 

 plains of the river Columbia, under the shade of Puruhia Iridentata." 



These plants vary slightly in the length of calyx-lobes and petals, and consider- 

 ably in the toothing of their upper leaves, but they appear to intergrade and not to 

 be in any case geographical variations. Nos. 523 and 748 may be M. yracilcnta. 

 Specimens were observed in the southern part of tbe Funeral Mountains, near Sara- 

 toga Springs (No. 252), and in a canon west of Amargosa; at Resting Springs and 

 the mountains east of them (No. 341); in Furnace Creek Canon (No. 351); in the 

 Vegas Wash (No. 410); between Ash Meadows and Furnace Creek (No. 441); in 

 Johnson (No. 523), Surprise, Hall, Willow Creek (No. 748), and Mill Creek cations, 

 Panamint Mountains; ami near Crystal Spriug, Coso Mountains (No. 937). 



Mentzelia congesta Nutt. in Torr. &, Gr. Fl. i. 534 (1840). Type locality, "Rocky 

 Mountains, on Lewis River." 



Near Cystal Spring, Coso Mountains (Nos. 911, 933). This species, although col- 

 lected heretofore in widely separated localities, appears to be rare, and was seen in 

 but one locality by the expedition. It is distinguished from other species by its 

 large bracts which in No. 933 (tbe more nearly typical specimen) are white-metubran- 

 aceous and green-margined, and in No. 911 membranaceous only at the base, and by 

 the flowers congested in glomerules terminating the branches. The leaves of No. 933 

 are nearly entire, those of No. 911 piunately lobed. No. 911 is referred here doubt- 

 fully and may be a very large specimen of M, albicaulis. It grew in rich, moist soil. 



• Wats. Index, 391 (1878;. a Amer. Nat. ix. 144 (1875). 



