

[Vol. 2 



144 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Family 168. Loganiaceae. Herbs, shrubs, and trees with 

 mostly opposite simple leaves and pentamerous or tetramerous 

 flowers; corolla-lobes imbricated or contorted; stamens mostly 

 4-5; ovary 2-celled (rarely 4-celled) ; ovules 1-many; endo- 

 sperm fleshy. Gdsemium, Logania, Spigelia, Strychnos. (Pf. 



4 2 : 19. ) 



Family 169. Gentianaceae. Gentians. Mostly herbs, with 

 usually opposite undivided leaves and pentamerous or tetram- 

 erous flowers ; corolla-lobes contorted, valvate, or induplicate ; 

 stamens 4-5; ovary bicarpellary, usually 1-celled; ovules 

 many; endosperm copious. Erythraea, Gentiana, Eustoma, 

 Menyanthes. (Pf. 4 2 : 50.) 



Family 170. Apocynaceae. Dogbanes. Milky-juiced trees, 

 shrubs, and herbs, with opposite or whorled, simple leaves 

 and mostly pentamerous (rarely tetramerous) flowers; 

 corolla-lobes contorted or valvate; stamens 5 (or 4), with 

 granular pollen; ovary 2-celled or the carpels separating; 

 ovules many; endosperm fleshy. Vinca, Apocynum, Nerium. 

 (Pf. 4 2 : 109.) 



Family 171. Asclepiadaceae. Milkweeds. Milky- juiced 



herbs and shrubs, with opposite, whorled (or alternate) leaves 

 and pentamerous flowers ; corolla-lobes contorted ; stamens 5, 

 with agglutinated pollen; ovary of two separated carpels with 

 one discoid stigma; ovules many; seeds usually comose; 

 endosperm fleshy. Asclepias, Enslenia, Ceropegia, Stapelia, 

 Hoy a. (Pf. 4 2 :189.) 



Order Pole moni ales. Corolla actinomorphic, becoming 

 somewhat zygomorphic in the later families; stamens alter- 

 nate with the corolla-lobes, of the same number and attached 

 to the corolla tube; leaves alternate (rarely opposite). 



(Species about 4112.) 



The relationship of this order to the Primidales, and 

 through it to the Caryophyllales, is so obvious as to make it 

 scarcely necessary to point it out here. 



Family 172. Polemoniaceae. Phloxes. Herbs (and shrubs) 



with alternate leaves (rarely opposite below) ; flowers pentam- 

 erous ; corolla-lobes 5, contorted ; ovary tricarpellary, 3-celled ; 



