Tas. 8779. 
‘CEREUS TuniLua. 
Costa Rica. 
CacTACEAE. Tribe EcHINOCACTEAE. 
Cereus, Haw.; Benth. et Hook. f. Gen, Plant. vol. i. p. 849. 
Cereus (§ Weberocereus) Tunilla, Weber in Bull. Mus. Nat. Hist. Paris, 
vol. viii. p. 460 (1902); K. Schum. Gesamb. Kakt. Nachtr. p. 60; 
a C, Biolleyi, Weber, caulibus latioribus et aculeatis differt. 
Fruticulus subrepens, ramosus, parce radicans, Caules subgraciles, tetragoni, 
raro trigoni vel pentagoni, virides, angulis obtusis; pulvilli circiter 1°5 cm. 
sejuncti; aculei 3-5 mm. longi, divaricati, graciles vel crassiusculi. Flores . 
laterales, solitarii, patentes, circiter 6 cm. longi. Calycts tubus circiter 
1 em. latus, basi copiose setosus; lobi oblongi, subobtusi, patentes, 
2-2°5 cm. longi, pallide brunnei; squamae quam calycis lobi breviores, 
acutae, reflexae. Petala elliptico-oblonga, obtusa, subpatentia, numerosa, 
lilacino-rosea. Stamina numerosa, inclusa; antherae oblongae, flavae. 
Stylus inclusus. Bacca elongata, setoso-spinosa, flava, edulis.—Webero- 
cereus Tunilla, Britton & Rose in U.S. Dept. Agric. Contrib. Nat. Hist. 
vol, xii. p. 481. Cereus Gonzalezti, Weber in Bull. Mus. Nat. Hist. Paris, 
vol. viii. p. 460; K. Schum. Gesamb. Kakt. Nachtr. p. 60.—R. A. Rours. 
The attractive species now described is a native of 
Costa Rica. It was presented to the Kew collection in 
1913 by Mr. C. H. Lankester. Since its arrival it has 
thriven well in the Cactus House at Kew. It produced 
flowers for the first time in October, 1917, when the 
accompanying figure was prepared. The study of species 
of the Cactus family presents several difficulties. Owing 
to the trouble experienced in preserving them satisfac- 
torily they are, as a rule, but imperfectly represented in 
herbaria. Their determination from descriptions unac- 
companied by drawings or photographs is often some- 
what uncertain. Even where there are ample material and 
adequately illustrated descriptions, students of the family 
often are beset with doubts as regards the delimitation 
not only of the species themselves, but also of the genera 
to which they should be referred. In the present 
instance all the difficulties alluded to have been encoun- 
OcroBeR--DECEMBER, 1918. 
