FABACEAE 613 



14. ROBINIA L.i 



Shrubs or trees, with glabrous, glandular or bristly foliage, sometimes armed with 

 spine-like stipules, the foliage not grand ular-dotted. Winter buds naked, in the petiole- 

 bases. Leaves alternate : blades unequally pinnate : leaflets opposite or nearly so, the 

 blades entire. Flowers perfect, in axillary or rarely terminal racemes. Calyx pedicelled : 

 lobes 5, acute, the 2 upper more united than the rest and often shorter. Corolla white, 

 pink or purplish : standard with a broad reflexed blade, naked within : wings curved, free : 

 keel-petals incurved, united below. Stamens 10, diadelphous ; the free filament sometimes 

 united to the middle of the tube. Anthers alike or those opposite the petals smaller. 

 Ovary stalked. Style subulate. Ovules several. Pod narrow, flat, short-stalked, glabrous, 

 bristly or prickly. Seeds oblique, with a thin crustaceous testa. LOCUST. 



Pods smooth and glabrous : corolla white. 1. R. Paeudacaoia. 



Pods prickly, hispid, bristly or glandular : corolla pink or purplish. 

 Peduncles not hispid. 



Twigs, and often the petioles and pedicels, viscid. 2. R. viscosa. 



Twigs and peduncles not viscid. 



Leaves, twigs and peduncles glabrous. 3. R. Boyntonii. 



Leaves and branches of the inflorescence pubescent. 4. R. EUiottii. 



Peduncles hispid. 



Twigs hispid. 5. R. hispida. 



Twigs merely pubescent. 6. R. nana. 



1. Roblnia Pseudacacia L. A tree 6-35 m. tall, with firm brown furrowed bark, 

 hard and very durable wood, especially in contact with the soil, horizontal or spreading 

 branches, and short twi^s, forming an oval or irregular crown. Foliage and inflorescence 

 glabrous, or soon becoming so : stipules spiny on vigorous shoots : leaflets 9-19, the blades 

 thin, 2.5-4.5 cm. long, elliptic or ovate : racemes drooping, dense, 10-25-flowered, 1-2 

 dm. long : corolla 15-20 mm. long, white, except a yellow spot on the standard : pods 

 glabrous, flat, 5-10 cm. long, 10-15 mm. wide, 3-10-seeded. 



Native from Pennsylvania to Iowa, Georgia and the Indian Territory. Also naturalized in north- 

 eastern North America. Spring. 



2. Robinia viscosa Vent. A shrub, or exceptionally a small tree 3-8 m. tall, with 

 rough dark gray bark, and spreading branches forming a round crown, or in cultivation 

 much larger. Twigs, pods, and often petioles and peduncles glandular-viscid : foliage and 

 inflorescence glabrate or appressed -pubescent : stipules small, setaceous, exceptionally 

 spiny on vigorous shoots : leaflets 11-27, the blades thick and firm, ovate, oblong or ellip- 

 tic, 2.5-4 cm. long : racemes 5-8 cm. long, 6-15-flowered, ascending: corolla 15-22 mm. 

 long, pink : pod flat, 5-8 cm. long, often contracted between the seeds, sparingly glandular- 

 hispid, 2-7-seeded. 



In dry rocky woods, middle North Carolina to Alabama. Local. Often escaped from cultivation 

 in the Atlantic States. Spring. 



3. Robinia Boyntonii Ashe. A large shrub 2-3.5 m. tall, with ascending branches. 

 Twigs glabrous or at first minutely pubescent : stipular spines none : leaves 1-1.5 dm. 

 long ; leaflets 7-13, the blades oblong or elliptic, 1.8-2.5 cm. long, soon glabrous : racemes 

 loosely 8-12-flowered : corolla rose-purple or pink, with white, about 18 mm. long ; 

 standard with the blade abruptly contracted into the claw : peduncles ascending or spread- 

 ing : pods slender, hispid. 



On mountain slopes, usually at high elevations, North Carolina and Tennessee to Georgia and 

 Alabama. Very local. Spring. 



4. Robinia Ellidttii (Chapm. ) Ashe. A shrub 6-15 dm. tall. Stem erect, virgate, 

 with few short, stout branches near the summit, the twigs, especially when young, white 

 or grayish canescent : stipular spines short and stout : leaves 10-14 cm. long ; leaflets 

 11-15, the blades elliptic, 1.5-2.8 cm. long: calyx, peduncles and pedicels canescent: 

 corolla rose-purple or purple and white : pods linear, hispid. 



Chiefly near the coast, North Carolina to Georgia. Local. Late spring. 



5. Robinia hispida L. A straggling shrub 3-10 dm. tall, often branching from the 

 base. Twigs, stem, peduncles, and often petioles and calyx, densely bristly hispid, or 

 occasionally nearly smooth : stipular spines short, often present : leaves 1-2 dm. long ; 

 leaflets 7-11, rarely 13, the blades oblong to nearly orbicular, 1.8-3.5 cm. long, glabrate: 

 racemes 3-5-flowered : corolla about 25 mm. long, purple or red-purple : pods 5-8 cm. long, 

 stout, few-seeded, densely hispid, and often glandular-hispid, with purple bristles. 



In and near the mountains, Virginia and Kentucky to Georgia and Alabama. Spring and early 

 summer. 



1 Contributed by Mr. W. W. Ashe. 





