Rubiacees.] 



MEXICO— SUPPLEMENT. 



429 



carpels, shown at figs. 3 and 4, and then the dissepiment is clearly seen to be double (fig. 7.) and of quite a 

 distinct substance (not herbaceous, but between membranous and coriaceous) from the valve : and these, singly 

 or two together, may often be seen among the clusters of fruit, resembling white, oval chaffy scales. In 

 other words, the dissepiments sometimes fall away with the respective cells or carpels and sometimes remain 

 attached to the receptacle after these latter have separated. This receptacle is a small spongy conical body 

 (fig. 4.) whose apex reaches to the point of attachment of the seed. The valves are almost hemispherical ; 

 one frequently bears three teeth of the calyx, and the other two. The cavity is entirely filled by the seed, 

 which is nearly hemispherical, transversely wrinkled, anteriorly marked with a deep longitudinal furrow, and, 

 near the base of that furrow, with a scar where the seed was attached to the dissepiment. Among the cap- 

 sules are numerous setas. 



The habit of Bigelovia, it must be confessed, is completely that of Spermacoce, as is that of Diodia like- 

 wise ; and we cannot but agree with Achille Richard in his observations on the Genus Spermacoce, Mem. sur 

 la Famille des Rubiacees, p. 150. " Un examen attentif d'un tres grand nombre d' especes nous a convaincu 

 de la necessite de reunir en un seul les trois genres, Spermacoce, Diodia et Borreria {Bigelovia) ; c'est 

 toujours un meme type d'organisation, non seulement dans toutes les parties de la fleur, mais encore pour le 

 fruit d'apres lequel on a fonde la distinction de ces trois genres. En effet que les deux coques restent par- 

 faitement closes comme dans les Diodia, ou bien qu'elles offrent une fente longitudinale comme dans les 

 Borreria, ou enfin que la cloison reste completement adherente a Tune des coques, tandis qu'elle manque 

 dans l'autre coque comme dans les veritables especes de Spermacoce ; nous ne voyous la, nous le repetons, 

 qu'un meme type d'organisation, d'autant plus que tres-souvent ces caracteres ne sont pas si nettement dessines 

 qu'il soit facile de rapporter une espece a telle ou telle de ces trois modifications. Nous pensons done qu'au 

 lieu d'en former des types de genres, elles peuvent simplement etre employees pour etablir des subdivisions ou 

 sections dans le genre Spermacoce, qui est fort nombreux en especes." 



Tab. XCIX. B. — Fig. 1, 2. Capsules ; Jig. 3, 3. Valves or carpels separated from the receptacle (Jig. 4.) ; 

 Jig. 5, 5. Valves separated from the dissepiments, which latter remain attached to the receptacle (Jig. 6.) ; 

 Jig. 7. Back view of a seed ; (at Jig. 5. The inner face of the seed is seen) : — magnified. 



1. Mitracarpum Schizangium ; diffusum suffruticosum, ramis subtetragonis pubescenti- 

 bus, foliis oblongo-lanceolatis acuminatis utrinque et margine scabris, stipulis pubescenti- 

 bus membranaceis setis rigidis, floribus axillaribus verticillatis et terminalibus capitatis 4- 

 phy His, filarnentis inclusis, seminibus cruciatim 4-lobis, lobis emarginatis. (Tab. XCIX. 

 A.) De Cand. Prod?-. 4. 572. Book, et Am. supra, p. 295. — Schizangium durum. Bartl. 

 in Herb. Hcenke. (DC.) 



Hab. San Bias to Tepic. 



Caulis pedalis ad sesquidepalem, tereti-obscure tetragonus, glaber vel subpuberulus, basi suffruticosus, dif- 

 fusus, ramosus, ramis brevibus. Folia opposita, (internodiis elongatis, praesertim in caule ubi 4-6 iincias longis) 

 lanceolata, rigidiuscula, 2-3 uncias longa, 3-4-lineaslata, utrinque acuminata, vix petiolata,subtrinervia, vel potius 

 nervis paucis costa parallelis scabriuscula, ad margineni et ad nervos sublus scabra, pagina inferiore subpubes- 

 centia. Stipules latse, membranaccae, j)ubescentes, margine denticulatae et spinulis vel setis rigidis tribus 

 appressis ferentes ; seta intermedia longiore validiore. Flores parvi numerosi, glomerato-verticillati, in axillis 

 et in stipulis foliorum supremorum siti, vel terminales capitati, capitulo subtetraphyllo, inter flores setoso ; 

 setae numerosae. Flores brevissimc pedicellati. Cahjcis tubus globosus, subdidynius, obscure costatus glaber, 

 superne setoso-scaber, lirnbus 4-dentatus, dentibus subulatis, tjuorum duabus oppositis duplo longioribus latiori- 

 busque, tubum 4-plo superantibus, ininoribus albidis, omnibus rigidis erectis,marginibus setoso-scabris, diaphanis. 

 Corolla infundibuliformis, dentibus calycinis longior, extus pubescens, tubo gracili, limbo 4-lobo, lobis ovatis 



