THE AMERICAN MIDLAND NATURALIST 89 
-V.—CRITICAL NOTES ON NEW AND OLD GENERA 
OF PLANTS. 
BY J. A. NIEUWLAND. 
RHAMNUS. 
Some of the plants commonly included among the buckthorns 
had been even before Linnaeus put into a well recognized genus 
Frangula. Their generic standing had been adopted by writers 
as early as Cusa, Dodonaeus, Matthioli, Haller, C. Bauhin (Prod. 
160, 1620), Tournefort, and by moderns as late as Asa Gray.* 
The characterizations by the latter author distinctive from the 
genus RKhamnus are sufficient to need no repetition here. 
FRANGULA (Dodonaeus, Pempt., 6:2:25) ‘Trew, Herb. 
Blackw. also Miller Gard. Dict., 8th Ed. (1768), Duhamel, Traite 
Arb. Arbustes I, 246 (1875), etc. 
Frangula Alnus P. Miller, 1. c.? 
Rhamnus Frangula Linn., Sp. Pl., 193 (1753). 
Frangula caroliniana Asa Gray, 1. c. 
Rhamnus caroliniana Walt., Fl. Car., ror (1788). 
The genus Alaternus might deserve consideration as a genus 
that may be separated from our aggregate Rhamnus. None of the ° 
plants are to be found in our region. Cardiolepis (Endotiopis) 
Raf., Neog. 2, (1825) based on the Rhamnus lanceolata Pursh, 
Fl. Am. Sept., 166 (1814) has but two nutlets in fruit and the 
parts of the flower in 4’s. 
APETLORHAMNUS, A New GENUS 
The presence or absence of petals when a constant character 
would seem in itself to be a almost sufficient-reason to segregate 
4 plant or plant group in. to a new genus. Many such lately pro- 
posed have not nearly as notable a reason for existence and are 
accepted by botanists without question. We have been anything 
but logical in our admission or non-admission of genera. In 
any ordinary key for the determination of plants the student is 
loath to find that he must look both among the Apetalae and the 
Choripetalae and even perhaps the Sympetalae to be able to find 
1 Gen. Pl. 177, vol. Tl (840). 
2 This is the stupid duplicate binary Frangula Frangula according to 
the American codes. 
