022 PORTULACE^. [Porhdaca. 



branches are rou^h ; but I scarcely think it other than a var. From the B. nuda of Nuttall it differs in the 

 number of its petals. The name would be more applicable to the followiug species. 



3. B, albicaulis; petalis 5 obovatis (parvis), staminibus petaloideis nullis, bracteis nullis, 

 caule la^vissimo nitido albo. Douglas^ MSS. apud Hort Soc. Lond. — Mentzelia albicaulis. 

 Douglas, in Herb, nostr. 



Annua, par\'a, decumbens, basi prrecipue ramis erectiusculis altemis, Isevissimis, nitidis, albis. Folia 

 reraota, lanceolata, sinuata, scabra. Flores nunc in axiUis solitarii, plenimque 3-5 cong-esti ad apices ramo- 

 vum, parvi, ebracteati. Calycis segmenta subulata, scabra, erecto-patentia, vix 2-3 lineas longa. Petala 5, 

 Icw^tudlue calycis, obovata, " mucronata" flava. Stamina 30 petalis subbreviora. Filamenta omnia con- 

 formia, filiformia, libera, basi dilatata. AntkertB subrotundie, biloculares : Loculi appositi, ad marginem 

 dehiscentes. Genven infenim, unciam longrim, cylindraceum, hispidum, uniloculare; receptaculis tribus 

 parietalibus. Ovula uniserialia. Capsula sesquiunciam longa, cylindracea, calyce coronata. Semina 

 plurima, tetragona, albumiiios'a. Embryo inunersus, cylindraceiis, curvatus ; radicula ad hilum versa, 



Hab. On aiid sandy plains of the river Columbia, under the shade of Purshia tridentata. Douglas, — 

 Mr. Doun^las seemed to be doubtful whether this new plant should be referred to Bartonia or Mentzelia, 

 It partakes, indeed, in some characters of the one, and some of the other. Mr. Nnttall, who has perhaps 

 alone of any living Botanist had the opportunity of examining both Bartonia and Mentzelia in a recent 

 state, and who may be considered to have established the former genus, says that " nothing essentifJ 

 separates Bartonia from Mentzeliay except the augmentation of petals, and the structure of the capsules 

 and seeds." In regard to the augmentation of petals, Mr. JVuttall himself observes that in Bartonia their 

 number varies from ten to fifteen. We have shown in the two preceding species, that it is reduced to five, 

 but with five petaloid stamens, or imperfect petals. In the present plant, the petaloid stamens are wanting ; 

 and the number of petals exactly accords with Mentzelia. Again, in Bartonia^ the seeds ought to be, 

 according to Nuttall, " numerous, arranged horizontally in a double series ;" in Mentzelia, the " seeds are 

 ;5-6, longitudinally arranged." In our plant, the seeds are numerous (25-40, Dmtgl^, placed in a single 

 series, — For a knowledge of the structxu*e of the flowers and seeds of this plant, I am indebted to a beautiful 

 drawing which accompanied the specimen lent to me by Professor Lindley, and made by that admirable 

 Botanist. 



Ord. XXXVII. PORTULACE^. Juss. 



1. PORTULACA. Tourn, 



CaL aut liber aiit imo ovario adhserens, bipartitus, demum basi circumscissus et deciduus. 

 Pet 4-6 aequalia, inter se libera aut Ima basi concreta, calyci inserta. Stam. 8-15, fila- 

 mentis liberis interdum ima corolla adnatis. , Ovarium subrotundum. Stylus apice 3-6- 

 fidusj aut stylus et stigmata 3-8 elongata. Capsula subglobosa 1-locularis medio circiun- 

 scissa. Semina 00 placentae centrali adfixa.— Herbse carnosce hiimiles. Folia sparsa inie- 

 gerrijna. crassa, iri axillis- scepe piligera, circa flores congesta aut suhverticillata. Flores horis 

 9-12 mtitutiriis sole eorpansi. — Genus heterogeneum et forsan dividendum, sed capsula cir- 

 cumscissa nunc facile distinctum. DC, 



1. P. oleracea; foliis cuneiformibus carnosis, axiUis geniculisque nudis, floribus sessilibus. 



Linn. Sp. PL p, 638. De Cand. PL Gras. t. 123. EllioU, Carol r. 1. i?- 534. Pursh, PL 

 Am. V. 2. p, 365. 



IIab. About Norway House, and banks of the Hill River. Dr. Richardson, J)/-ummond. 



