ACANTHACEAE. 401 



Fertile stamens only 2. 



Shrubs with opposite spines ; staminodia 2. 4. Anthacanthus. 

 Unarmed herbs or shrubs ; staminodia none. 



Seeds 6-12. 5. Andronraphis. 



Seeds 2-4. n r . . 



Capsule oblong. 6. Justicia. 



Capsule ovate or orbicular. 7. Diapedium. 

 Twining vines ; flowers solitary, axillary, subtended by 2 large 



bracts; stamens 4. 8. Thunbergia. 



1. BLECHUM P. Br.; Juss. Ann. Mus. Paris 9: 2G9. 1807. 



Perennial herbs, with repand-dentate or entire, petioled leaves, and small 

 flowers in dense terminal spikes, the large foliaceous bracts imbricated. Calyx 

 5-parted, the slightly unequal segments linear-subulate. Corolla with a slender 

 tube little expanded above and a spreading, nearly equally 5-lobed limb, the 

 lobes rounded. Stamens 4, didynamous, borne at or above the middle of the 

 corolla-tube; anthers oblong, their sacs parallel. Ovules few or several in 

 each ovary-cavity; style with a subulate apex. Capsule ovate or suborbicular 

 with a short, narrowed base. Seeds orbicular. [Name Greek, originally ap- 

 plied to some different plant.] About 4 species, natives of tropical America. 

 Type species: Buetiia Blechum L. 



- 1. Blechum Brownei Juss. Ann. Mus. Paris 9: 270. 1S07. 



Annual, puberulent, erect or ascending, 2-7 dm. high, branched, the 

 branches slender. Leaves ovate, thin, petioled, 2-7 cm. long, acute at the 

 apex, obtuse or narrowed at the base; spikes dense, 4-sided, 3-6 cm. long; 

 bracts ovate, pinnately veined, 1-1.5 cm. long, loosely strigose and ciliate, 

 acutish at the apex, rounded at the base; corolla whitish, a little longer than 

 the subtending bract; capsule oblong, puberulent, about 6 mm. long. 



Waste places in good soil, Abaco, Andros, New Providence and Eleuthera : 

 West Indies and continental tropical America; Philippine Islands. Blechum. 



2. RUELLIA L. Sp. PI. 634. 1753. 



Perennial herbs, or shrubs, mostly pubescent, with entire or rarely dentate 

 leaves and large flowers, solitary or clustered in the axils, or cymose in 

 terminal panicles. Calyx 5-cleft or 5-parted, the segments narrow. Corolla 

 funnelform or salverform, the tube usually narrow, slightly enlarged above, 

 the limb spreading, 5-lobed, the lobes obtuse. Stamens 4, didynamous. Anther- 

 sacs not mucronate at the base. Apex of the style recurved ; stigma simple, or 

 of 2 unequal lobes. Capsule oblong or club-shaped. Seeds compressed, ovate 

 or orbicular, attached by their edges to the retinacula. [Named for I. De la 

 Ruelle, 1474-1537, an early French herbalist.] About 200 species, mainly of 

 tropical America. Type species: Euellia tuberosa L. 



> 1. Euellia tuberosa L. Sp. PI. 635. 1753. 



Roots narrowly fusiform, clustered; stem erect or ascending, branched or 

 simple, 2-6 dm. high, finely pubescent. Leaves ovate or oblong, 10 cm. long 

 or less, undulate, finely pubescent, narrowed into margined petioles; cymes 

 several-flowered, peduneled ; bracts narrow, small; calyx hispid-pubescent, its 

 linear lobes 12-20 mm. long; corolla purple, 4-6 em. long, its tube rather 

 abruptly expanded above; capsules puberulent, about 1.5 cm. long. 



Shaded grounds, New Providence, Eleuthera and Cat Island: southern United 



States; West Indies and continental tropical America. Trr.i:ia>rs Ki'KI.i.ia. 



