222 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



| VOL. 10 



In describing his Chalepophyllum speciosum from Mount Roraima, X. E. 

 Brown stated that no fruits were seen in the Mc Connell & Quelch specimens. 

 Moreover, Standley had only flowering material of his C. tatei from Mount Duida. 

 Although he described fruits and seeds of C. latifolium, Standley did not observe 

 the loculicidal dehiscence of the capsule, which is present on the holotype spec- 

 imen preserved (NY). At the time he described C. coriaceum, Gleason did not 

 have access to mature or dehiscent fruit, thus no mention was made of the fruit, 

 or of its mode of dehiscence. 



A careful examination of the species described under Chalepophyllum by 

 Brown, Standley, and Gleason, has revealed, in addition to the character of 

 loculicidal type of dehiscence, other significant morphological characters, which 

 furnish the basis for a new generic status for the plants of the Venezuelan table 

 mountains heretofore passing as species of Chalepophyllum. These additional 

 characters are discussed in the following paragraphs. 



Stipule: In true Chalepophyllum , represented by C. guianense, the stipule is 

 inconspicuous, low, broadly triangular, and barely acute. In the later-described 

 large-flowered Venezuelan taxa (Maguireothamnus) , the stipules are connate into 

 a sheath which is contracted into a prominent persistent triangular-subulate free 

 portion 2-6 mm long. 



Bract: In true Chalepophyllum, represented by C. guianense, the base of the 

 pedicel is subtended by two minute ovate bracts barely 1 mm long. In the taxa 

 now segregated as Maguireothamnus the two bracts at the base of the flower are 

 conspicuous and foliose, varying from 7-16 mm long. 



Style: In true Chalepophyllum the style is glabrous throughout. In Maguireo- 

 l]> a nut us the uppermost portion of the style is densely covered by white papillae. 



Corolla : length : In true Chalepophyllum the corolla is quite small, the corolla- 

 tube varying from 1-1.6 cm long, the lobes 0.6-1.5 cm long. In contrast, in 

 Maguireothamnus the corolla is large and showy, the elongated tube mainly 5-12 

 (rarely 4) cm long, and the lobes mainly 2-5 cm (rarely 1.5) long. 



Corolla: bearding at orifice: In true Chalepophyllum the orifice of the corolla 

 is thickly bearded with elongated multicellular hairs up to 2 mm long. These 

 protrude from the orifice and extend as well up to the base of the corolla-lobes, 

 the bearding thus showing prominently in herbarium material. In Maguireotham- 

 nus the liairs are short, inconspicuous, do not extend to the base of the corolla- 

 lobes, nor protrude at the orifice, so that in herbarium material the orifice ap- 

 pears naked. 



Leaves : In true Chalepophyllum the lower surface of the leaf-blades has all the 

 veins prominently elevated and tomentulose into a characteristic tessellated, 

 rugulose, areolate surface, and the lateral nerves are prominent. In contrast, the 

 taxa of Maguireothamnus have smooth and veinless lower surfaces of the leaf- 

 blades, or, if pubescent, the Jiairs are simply dispersed, and the lateral nerves 

 are absent or obsolete. 



Glutinous exudate: In true Chalepophyllum a glutinous or sticky exudate 

 appears in the uppermost parts of the branches, usually at the base of the 

 petioles or at the base of the pedicels or peduncles. In Maguireothamnus no 

 exudate is present. 



