228 



XCVIII. ACANTHACKfi (cLARKe). 



[Isogloi 



small, ellipsoid, compressed, 4-seeded ; stalk short (or not longer than 

 the ellipsoid part), cylindric, solid ; placentae not rising elastically from 

 the base of the valves ; seeds small, tubercular-scabrous, tubercles often 

 elongate. — Herbs, with slender branches, sometimes 6 ft. high. Leaves 

 ovate or elliptic, acuminate at either end, entire, petioled ; upper leaves 

 often sessile, cordate. Inflorescence panicled, terminal and with axillary 

 branches, pubescent, often glandular ; floral leaves and bracts usually 

 narrow or small (but larger and enclosing the calyx in /. substrobilina 

 and /. Gregorii). 



Species 25, in Africa and the Mascarene Islands, besides a few in India. 



By some inadvertence, Lindau, in Engl. & Prantl, Pflanzenfam. iv. 3 B. 342, 

 separates Isoglossa from all other JusticiecB by the character of 4 stamens ; it never 

 has more than 2. 



*Eu- Isoglossa. — Anther-cells elliptic, one above the other. 

 Most of the flowers' pedicelled. 

 Species of West Africa. 



Leaves very thin, nearly glabrate . . . . 

 Nerves of leaves strong, beneath scabrous 

 Species of East Africa. 



Mature leaves glabrous or very nearly so. 

 Corolla ^-§ in. long. 

 Panicle hairy. 



Leaves up to 3 in. long . . . , 



Leaves up to 7 in. long . . . , 



Panicle glabrate ..... 

 Corolla nearly 1 in. long .... 

 Mature leaves pubescent, at least on the nerves. 

 Bracts narrow. 

 Panicle terminal. 



Leaves f in. long ; corolla \ in. long 

 Leaves 4 in. long ; corolla § in. long 

 Panicles numerous, terminal and axillary 

 Bracts ovate (small) . . . . . 



Flowers in small heads on the branches of a panicle. 

 Leaves to the flower-clusters (or bracts) narrow, not 

 enclosing the calyx. 

 Sepals j'g-^ in. long, subpetaloid, hairy . 

 Sepals i in. long, linear, green . . . , 



Sepals ^ in. long, subulate in the upper half . 

 Leaves to flower-clusters (or bracts) enclosing the 

 calyx. 

 Floral leaves distant, ovate, subacute 

 Floral leaves imbricate, suborbicular 



1. I. glandulifera. 



2. I. nervosa. 



3. 1. laxa. 



4. I. membranacea. 



5. I. lactea. 



6. I. Volkensii. 



7. /. parvifolia, 



8. /. somalensis 



9. /. strigosula. 



10. /. mossamhicensis. 



11. I. runssorica. 



12. I. oerstediana. 



13. I. milanjienns. 



14. I. Qregorii. 



15. /. substrobilina . 



Tseud-Adhatoda. — Anther-cells oblong, parallel, at 



nearly equal height. 

 Corolla-lips as long as the tube. 



Panicle-branches few ; corolla 1 in. long . . 16, /. gr.andijiora. 



Panicle-branches very many; corolla \ in. long . 17. I.floribunda. 



Corolla-lips much shorter than the tube. 



Hairs on panicle, and sepal tipped with red glands . 18. T. rubescens. 



Hairs on sepals long, white, without red glands . 19. I. Ixodes. 



