2?8 out, fl^t or sliphtly concave on the upper side, v'itli obtuse or 

 rounded edges, very convex and bluntly keeled on the back, obtuse 

 or subacute et the' apex, smooth, glabrous, dull brownish, reddish- 

 grey or dark grey-green tinted vith dull purple, faintly glaucous, 

 thickly but rather inconspicuously dotted with darker green. 

 Flower' solitary, terminal, sessile, with a pair of bracts 2§-5 

 lines long at its base. Calyx S-^-lobed, smooth, glabrous; tube 

 above the ovary 2-3 lines long, cur-shaped; lobes reflexed or revo- 

 lute, 2-4 lines long, ovate, obtuse, brovmish, some v/ith membranous 

 white margins. Corolla li-l^ inch in diameter, ai^psrently remaining 

 expanded day and night irrespective of cloud or sunshine if the 

 temrierature is warm enough and lasting 5-6 days, scentless; petals 

 50-60, free, in about 2 series, Isx, arising from the top of the 

 calyx-tube, spreading rathe^^ v/idely in the morning, becoming very 

 revolute late in the afternoon and evening, 0-12 lines long, -|-i 

 line bropd, linear or cunetely linear, often obtusely toothed at 

 the aner, bright yello\«.' fading into white at the base, paler on 

 the beck. Stamens numerous, erect, at first collected into a cy- 

 lindrio or slightly conical, dense bundle about 3 lines long, 

 finally with some of the outer stamens separating from the bundle 

 and standing erect or spreading loosely around it; filaments white; 

 anthe-^s deen yellow; no staminodes. ^tyle none; stigmas 11-15, a- 

 rising from the conical tor of 



229 the ovary, finally about as long es the stamns (l^-3 lines long), 

 filiform, erect, curved as or contorted at the tips, pale yellow- 

 ish. *^very conical at the top, 11-15 celled; placentas on the 

 outer v;all of the cells and also partly on the central axis. Cap- 

 sule subglobose, 6-7 lines in diameter when closed, with 11-15 

 valves and cells; valves 3-4 lines long and about 1 line broad at 

 the base, very acute, brovTi, with a very prominent membranous crest- 

 like keel down the middle of the inner face; expanding-keels sep- 

 arate, r»arallel, stout, dark brov.Ti, about half as long as the 

 valve and then t>roduced into free, avm-like points with a membran- 

 ous tapering wing on their outer margin and considerably shorter 

 than the valve; cells as for the genus, each v.'ith its opening near- 

 lyclosed by a compressed dark brown tubercle. Seds 2/3-4 line in 

 diameter, comnressed, ovoid or suborblcular in outline, v.lth a 

 consnicuous nipple at one end, very minutely tuberculate under a 

 lens, dark brown. ^ 



Mesembryanthemum optatxim, N, S, ^v,, in Journ, Linn. Sqc, v, 

 XLV, p. 71 (1920). 



Oudtshoorn Division: Bank iioogte, Mrs. "'iggett 3, Iviarloth 

 6341. 



A Plant of this snecies flowered at Kew in November, 1917, 

 but is place of origin was unknown, recently, however, it has again 

 been introduced by Mrs. *^ . "''iggett, who discovered it at the 

 locality mentioned. 



The flov-ers of this species, although apparently expanded all 

 day, orien more widely late in the afternoon and evening than in 

 the morning, and pre sensitive to temperature. A coloured drawing 

 of it that I have made (and which I hope to publish) represents 

 the corolla s seen exnanded in the morning, but in the evening 

 of the same day the central rart had opened more v/idely and the 

 T3etals were very much rolled back, so that the calyx was entirely 

 concealed. One afternoon, unon being removed from the greenhouse 

 to a room of cooler temperature, the flower closed up, but during 

 the eving when the room had become much v.'armer, it expanded again. 

 So that it is evidently rore sensitive to temperature than to 

 sunlight. 



