Triosteum Caprifoliaceae 885 



ones, short-pubescent, glandular, the hairs mostly not more than 0.5 mm long, 

 the longest hairs glandular, surface dull; fruit maturing in late October, 12-14 

 mm long, and 11-12 mm wide, subglobose, Ochraceous-Orange (Ridgway). 



1. T. p&rfoliatum. 



Principal and other leaves usually not connate, narrowed below into winged, sessile, 

 hardly clasping bases, generally less velvety; stem usually spreading-villous, 

 with few or no short hairs; sepals generally broader (in flower 1.5-2.8 mm 

 wide), obtuse or acute, sometimes purple tinged; corolla purplish red, often 

 lighter, the mouth 7-9 mm wide, usually more flaring; fruit usually maturing 

 less than 6 at a node, sometimes only 2 or 2 or 4 perfect ones and the others 

 aborted, villous with spreading hairs 0.75-2 mm long, the longest hairs not 

 glandular, interspersed with shorter, glandular ones, surface rather glossy; 

 fruit maturing from early August to early October, 11-18 mm long and 8.5-15 

 wide, ellipsoid-ovoid, Brazil Red (Ridgway). 



Cauline hairs up to 1.5 mm long; longest hairs of fruit 0.75-1 mm long 



2. T. aurantiacum. 



Cauline hairs 1.5-2 mm long or longer; pubescence of fruit 1-1.5 (2) mm long; 



hairs on upper surface of leaves up to 1 mm long 



2a. T. aurantiacum var. illinoense. 



Leaves glabrous or nearly so beneath, pubescence of sepals and corolla usually less 



than that of T. aurantiacum; sepals usually acute 



2b. T. aurantiacum var. glaucescens. 



Sepals hispid-ciliate, otherwise glabrous or sparingly short-hispid; stipules of leaves 

 usually extending beyond the sepals; flowers usually 2 at each node; corolla yellow, 

 14-18 mm long, loosely villous, slightly glandular, the lobes large and broad; stem 

 setose-hispid, the hairs nearly all long (longest hairs 1.5-2.8 mm long) ; leaves not 

 perfoliate, lanceolate to oblong-lanceolate, distinctly hispid-strigose above with 

 hairs 0.8-1.8 mm long; fruit maturing in September, about 8.5 mm long and 6.5 mm 

 wide, ellipsoid, Mars Orange (Ridgway) 3. T. angusti folium, 



1. Triosteum perforatum L. COMMON HORSEGENTIAN. Map 1944. 

 There are reports of this species from all parts of the state but since those 

 from the southern part were made before the species was divided, the 

 only way to consider the distribution is from the specimens at hand. It 

 is generally found in dry clay or sandy soil on white oak slopes and rarely 



in moist ground. 



Wiegand, in his article cited above, considers the following species, 

 T. aurantiacum, as a variety of T. perfoliatum. However, they seem suf- 

 ficiently distinct in Indiana to warrant treatment as species. Colonies of 

 both species growing in the Deam garden were observed for four years, 

 and notes were kept concerning them. 



T. perfoliatum was found to bloom from two to three weeks later than 

 T. aurantiacum, and to mature its fruit correspondingly later. It is a light 

 orange yellow when beginning to mature, gradually darkening until it is 

 Ochraceous-Orange (Ridgway). The fruit persists well into November, 

 resisting a temperature as low as 26° without harming the plant or causing 

 the fruit to shrivel or drop. By the latter part of October, the fruit of 

 T. aurantiacum began to dry up and to fall. 



Mass., Wis., Nebr., south to D. C. and in the mts. to N. C, Kans., and Mo. 



2. Triosteum aurantiacum Bickn. (Torreya 1: 26. 1901.) Map 1945. 

 Infrequent possibly throughout the state. It is generally found in rather 

 open, dry woods and more rarely in moist, sandy places in a prairie 

 habitat. 



