PITTIER — TREATMENT OF THE GENUS CASTILLA. 267 



A deeper and more intricate confusion was thus produced, so that the diag- 

 nosis of Hemsley's C. tunii—" afflnis C. elastica Cerv., a qua differt foliis basi 

 liiiud cordatis utrinque multo minus hirsutis, dnipcolis rcccptaculo fcrc omnino 

 immersis "—definitely excludes the Costariean species which furnished most of 

 the data of the detailed description. It also appears very doubtful whether 

 the two characters mentioned in the diagnosis are really combined in the Hon- 

 duran tunu, the specific peculiarities of which are practically unknown, though 

 its distinctness is hardly to be denied in advance of more adequate knowledge. 

 The previous history of the species and the application of the local Honduras 

 name "tunu" as the botanical designation of the same may also be taken as 

 indications of the Honduran specimens being intended to constitute the type 

 of Hemsley's species. Under such circumstances, and without denying the 

 possible identity of the hule macho and the tunu, it seems necessary to leave 

 Hemsley's name in abeyance until the real characters of the Honduras species 

 can be made clear. 



Such was the view taken in 1903 by Mr. O. F. Cook, of the U. S. Department 

 of Agriculture, after devoting considerable attention to the study of the Central 

 American rubber tree. a Basing upon the conclusive discrepancies in Hemsley's 

 diagnosis and on his own personal acquaintance, mostly acquired in tbe field, 

 with the several species of Castilla. he found it preferable to consider the Costa- 

 riean hule macho as a distinct species, taking as type a more complete set of 

 the same specimens that furnished a part of the description of Hemsley's C. 

 tunu, a course that appears to be justified by the evidence reviewed above. 

 3. Castilla australis Hemsl. Hook. Icon. PI. IV. 7: pi. 2076. 1901. Plate 24. 



Evergreen (V) tree with a smooth, erect trunk and horizontal branches. 

 Young twigs and leaves silky-tomentose. Fructiferous twigs thick. 



Petioles about 1 cm. long. Leaf blades coriaceous, oblong or oblong-lanceolate, 

 30 to 40 cm. long, 10 to IS cm. broad, slightly emarginate at the base, abruptly 

 acuminate at tip, glabrous or at first glabrescent above, hirsute, principally on 

 the midrib and primary veins beneath; margin undulate; primary veins 17 to 

 19, arcuate, running into each other along the margin, hardly impressed above, 

 prominent beneath. Stipules lanceolate, acute, 4 to 5 em. long, early deciduous. 

 Male inflorescences unknown. 



Female receptacles stipitate, solitary in the axils of the leaves; stipes 2 to 

 2.5 cm. long; bracts (scales) in several rows, acuminate, rather narrow and 

 apparently free. Perianth free to tbe base (according to drawing), lobulate at 

 crown, hairy outside. Style snort, thick, and hairy ; stigmas very short, cushion- 

 shaped, minutely hairy on the inner (upper) face (?). £ 

 Fructiferous receptacles not known. 

 (Description according to Hemsley and the notes quoted from I'earce, loc. 



cit.) 



Peru: Moito Zungo (region of Cuzco?), common in woods at 1,300 to 1,700 

 meters above sea level. Female flowers, January, I860, Pearce. 



Explanation of Plate 24. — Fig. a, loaf ; b, stipules ; c, a female inflorescence ; d, a 

 female flower ; c, pistil with part of the ovary removed ; /, an immature nut. Reproduced 

 from Hemsley, loc. cit., on a scale of one-half; in the original c-f said to be " enlarged." 



species. Further, Mr. Poisson states that " it is wonderful that a tree that sup- 

 plies a part of the rubber of Costa Rica, etc., is not yet known by botanists ; " this 

 is another double mistake, as C. costaricana has been known as such for over fifty 

 years and the hule macho does not afford any amount of commercial rubber. 

 a See citation, p. 253. 



