BOTANICAL REPORT. 447 



channeled on the upper surface, and keeled on the lower one, at least toward the hast', 

 leaving a triangular scar after falling" off. They are J— 1 inch, rarely as much as 1J 

 inches long, and J line, or sometimes, in the upper half, even 1 line, wide; in young and 

 vigorous shoots, I have seen the leaves flatter, shorter, and broader, almost lanceolate. 

 Their surface usually is perfectly glabrous; in specimens from Carson Lake, however, 

 I find the younger leaves covered with a rough and sometimes branched pubescence. 

 The leaves are sometimes on the lower part of the branches opposite, but commonly 

 alternating in f order. The staminate and pistillate flowers are both very imperfect, 

 but very different in their arrangement and structure: they usually occur on the same 

 plant, though some plants seem to bear scarcely any but staminate, others only pistil- 

 late, flowers. The staminate flowers are crowded into a deciduous spike oi anient, 

 terminating the branches. This spike is, before the flowers open, 3-5 lines long and 

 li lines thick, and very compact, exhibiting only the rhombic surfaces of the scales; 

 afterward it elongates to the length of .5-9 lines, showing the deciduous anthers under 

 and between the separated scales. The spike consists of 25-35 peltate angular scales, 

 pointed at the upper end, which cover 3-5 broadly oval anthers, sessile on the rhaclus, 

 i line long, 2-celled, opening laterally. The fertile flowers are usually solitary in the 

 axils of the leaves and sessile; in some specimens, I find a secondary flower just below 

 the primary one, and sometimes even below a branch, springing trom the same axil; 

 sometimes they are aggregated on abbreviated branchlets, torming irregular clusters. 

 The flower consists of a tubular calyx with an inconspicuous rim, investing the lower 

 half of the ovary, which is terminated by two unequal subulate stigmas, lateral in 

 regard to the stem. In the fruit, this rim is enlarged to a broad, circular, spreading 

 wing, 3-5 lines in diameter, green or sometimes red, which surrounds the upper third 

 of the fruit, The flattened vertical seed, inclosed in the membranaceous utrieulus, is 

 about 1 line in diameter, and contains a spiral embryo without an albumen, as already- 

 demonstrated and figured by Professor Torrey in Fremont's Report. 



The Greasewood is found in flower from June to August. 



The form from Carson Lake seems to be distinguished not only t>y the pubescence 

 of the younger parts of the plant, but also by its more squarrose growth, its subdioe- 

 cions flowers, and its aggregated fertile flowers and fruits; but the Greasewood . »t other 

 localities is also often subdieecious, so that when first described, it was considered a 

 truly dueeious plant. 



George Engelmann. 



