I. PLANTS FREMONTIAN^. 19 



of the filaments, and terminates in a capitate, slightly five-lobed stigma. The 

 capsule is similar in form to the ovary, only larger. It is of a chartaceous texture, 

 and apparently opens by chinks at the margin of the valves, vs^hich do not separate 

 from the axis. Seeds covering the large two-lobed placentae, ovoid, obtuse at the 

 base ; the reticulated testa covering closely the nucleus, except at the apex, where 

 it is produced into a short, conical, oblique appendage. The embryo is exceedingly 

 minute, obovoid, undivided, and situated near the base of fleshy and oily albumen, 

 with the radicle pointing to the hilum. 



This genus is intermediate between Hypopithys and Schweinitzia. Like the 

 former, it has a long style ; but it differs from it in the gamopetalous corolla, the 

 two-celled biporose anthers, close testa, &c. Schweinitzia, which has a similar 

 corolla, differs in its short thick style, and in the form as Avell as the insertion 

 of the anthers. 



There can be no doubt respecting the position of the embryo in this genus and 

 in Pterospora. After much patient dissection, I have obtained it repeatedly in 

 both genera. The ripe seeds of Monotropa and Hypopithys I have not examined, 

 but they have anatropous ovules, and therefore the radicle must be next the hilum. 

 Lindley and De Candolle, however, state that the embryo is situated at the apex 

 of the albumen ; but this I am convinced is a mistake. As, therefore, all the 

 genera of this group but one have two-celled anthers, there would seem to be 

 nothing to distinguish Monotropese from Pyrolese, except the parasitic habit, the 

 want of verdure, and the erect position of the anthers in the flower bud. There 

 is, however, a leafless species of Pyrola which serves as a connecting link between 

 them ; and I have already alluded to the half turning of the anthers in the 

 unexpanded flowers of Schweinitzia. In comparing these groups, there is still 

 another character which, I believe, has been hitherto overlooked. Some years 

 ago,* I remarked that the pollen in all the Ericaceae that I had examined was 

 compound, consisting of three or four united spherules, as in Epacridacese. At 

 that time, I had only looked at the pollen of the Ericese proper, and the Vaccinese. 

 Afterwards, I found that, in Monotropese, the pollen is simple ; while, in Pyrolese, 

 it is compound, consisting usually of three united grains ; but these are not so 

 easily observed as in the suborders just noticed. 



The genus Galax, which was first referred to Ericaceae by Michaux,t and after- 

 wards to a separate tribe of Pyrolacese by De Candolle, ought, perhaps, to be the 

 type of an order, or at least of a suborder. It is remarkable for its monadelphous 

 stamens and truly one-celled anthers. From genuine Pyrolea3 it differs besides in 

 its simple pollen, wingless seeds, and cyhndrical, axile, divided embryo. According 

 to Sir J. E. Smith,^ it was referred by Mr. Dryander to Saxifragacese ; and the 

 late Prof. D. Don placed it in his heterogeneous order Galacinese, which was 

 characterized so as to include Francoa. 



Endlicher enumerates among Pyrolese the little known genus Shortia,§ although 

 Dr. Gray gives no opinion of its affinities, merely observing, that it has the habit 



* Flora of the State of New York, i. p. 229. f Miclix. Fl. Bor.-Am. ii. p- ^^^ 



X Grammar of Botany, p. 164. § Gray in Sill. Amer. Jour. 42, p. 48. 



