60 xcviii. ACANTHACE^ (clarke). [Distichocahjx. 



IG. DISTICHOCALYX, Bentli. in Benth. et Hook. f. Gen. 

 PL ii. 1080. 



Calyx anticous 2 segments free to the base, posticous 3 united more 

 than I their length (only ^ their length in D. thunhergiijlorus). Corolla 

 large or medium ; tube inflated in upper half ; lobes 5, subequal, round, 

 contorted in bud. Stamens 4 ; filaments nearly glabrous, gland-bearing 

 near the top ; anthers all alike, not spurred ; pollen globose, echinate. 

 Style nearly glabrous, I stigmatic branch large spathulate, the other 

 obsolete ; ovary narrowly oblong, glabrous, with at least 4 (usually 0-8) 

 ovules in each cell. Capsule linear-cylindric, small, sl^nder, many- 

 seeded (usually perfecting 10-14 seeds where known) from the base ; 

 but in D. thunhergiiflorus (though similarly constructed) much larger. 

 Seeds having the faces glabrous, the margins with many white hygro- 

 scopic hairs. — Small shrubs, bearing cystoliths everywhere, sparingly 

 hairy (Z). hirsuta moderately hairy). Leaves petioled, entire. Flowers 

 purple-blue or white, 8-16 in a terminal spike or hfead, elongated and 

 loose in R. thunbergiijiorus ; bract close to the calyx, ovate or elliptic, 

 about as long as the calyx ; bracteoles very small, oblong. 

 Species 8, endemic in Tropical Africa. 



T. Anderson founded in MS. his ^enus Dischistocalyxm herb. Kew on six of the 

 species below ; he diagnosed the genus from Bnellia entirely by the calyx, and there- 

 fore he described as Ruellia thunhergiiflora the eighth species below, as it has the 

 calyx divided for § its length, often irregnlHrly or sometimes subequally 5-partite nearly to 

 the base. Bentham published the geuus as J)istichocalyx (in Benth. & Hook. f. Gen. 

 Pi. ii. 1080), making an error in the name and widening the calyx-character to include 

 liueUia thunhergiiflora. Dischistocalyx Lindau (in Engl. & Prantl, Tflanzenf. iv. 3B. 

 307) does not contain any one of the 7 species included by Bentham ; it has equal calyx- 

 segments, and is stated to have 10 or 12 seeds in each cell, but the two species which 

 Lindau really possessed, viz. his Dischistocalyx laxiflorus, and JJ. confertijlorns, have 

 only 2 ovules to each cell of the ovary, and are closely congeneric with Pseudostenosi- 

 phonium r ha mni folium, Lindau. The first six species of ])istichocalyx below described 

 are so intimately allied that the essential part of the description of all is included in the 

 above generic description ; it is remarkable that Bentham should have brought Jiuellia 

 thunhergiiflora here in the teeth of T. Anderson's generic characters (which make it a 

 Jiuellia) ; his instinct has been confirmed by the discovery that this species has the 

 pollen of Distichocalyx — not of Ruellia. 



Calyx 2 anticous lobes free, 3 posticous united nearly to the 

 top. Inflorescence dense. Capsule and seeds very 

 small. 

 Corolla 1^-2 in. long.^ 



Leaves Icbs than 2 in. broad. 

 Stem glabrous or nearly so. 



Leaves narrow-lanceolate ; corolla Ii in. Icmg . 1.7). angustifoliua. 

 Leaves elliptic-lanceolate ; corolla 2 in. long . 2. D. polyneurus. 



Stem and leaves thinly shaggy .... ?>. D. hirsutu-H. 

 Leaves 4^ in. broad ; corolla 1^ in. long . . . 4. D. grandifoUus. 

 Corolla about 1 in. long, rather slender. 

 Leaves up to 4-7 in. long. 



Leaves 7 in. long ; spike strobilat.e . . . . 5. /).. strohilinus. 

 Leaves 4 in. long ; head small, ovoid . . .6. D. capitellatun. 

 l^eaves up to 1^ in. long; head of 2-i flowers . . 1. D. brevij'olius. 

 Calyx divided | the way to the base. Spike elongate loose. 



(Capsule and seeds medium-sized 8. JJ. thunbergit- 



fiorufi. 



