\\II,.MATTUA. I95 



This very peculiar plant we have not been able to refer definitely to any of the above 

 species. It suggests in a way the other Hylocereus, which Dr. Rose also obtained in Vene- 

 zuela (No. 21835) an d which we have described as new in the Appendix. It, however, has 

 not yet flowered in the New York Botanical Garden where it is now being grown. 



PUBLISHED SPECIES. PERHAPS OF THIS GENUS. KNOWN TO US ONLY FROM DESCRIPTION. 

 Cereus radicans De Candolle, Prodr. 3: 468. 1828. 



This species has not been well understood since its original description. It is prob- 

 ably either a Selenicereus or a Hylocereus. It was described as prostrate, light green in 

 color, 3 or 4-angled, with rigid, slender, brown spines, of which 6 to 9 are radials and 1 

 is central. De Candolle refers it to Tropical America; Pfeiffer (Enum. Cact. 114), who 

 redescribed it in 1S37, refers it to Tropical America and the Antilles. Schumann did not 

 know it, but referred it to South America. 



Cereus rcptans Salm-Dyck (De Candolle, Prodr. 3: 468. 1828) is an unpublished name 

 which was first mentioned under C. radicans, while Cereus reptans Willdenow is referred by 

 De Candolle to Cereus pentagonus. 



Cereus horrens Lemaire, Hort. Univ. 6: 60. 1S45. 



Climbing and rooting; ribs 3, prominent, strongly tubercled; areoles distant, bearing copious 

 white down; spines 5 to 7, whitish, variable, stout, very long. 



This species seems to have been lost. Its flowers and fruit are unknown as is also its 

 origin. It is probably a Hylocereus. 



2. WILMATTEA gen. nov. 



A climbing cactus, epiphytic and rooting along the sides of the joints, slender, with few short spines ; 

 flowers solitary at the areoles (in one case 2 flowers seen), small for the tribe, nocturnal, with a narrow 

 limb and with a very short tube; ovary small, covered with ovate, imbricating, reddish scales, each 

 subtending a small areole filled with felt and occasionally with 1 bristle or more, perhaps sometimes 

 naked ; filaments and style short. 



One species is known, native of Guatemala and Honduras. The genus is named in 

 honor of Mrs. T. D. A. Cockerell (Wilmatte P. Cockerell) in recognition of her many 

 discoveries of rare plants and animals in Central America. 



In habit this plant resembles a slender-stemmed species of Hylocereus while the flower 

 and ovary bear similar scales and this led us at one time to consider it as a species of that 

 genus. The flowers, however, are so much smaller with scarcely any tube and bearing felt 

 and bristles in their axils that we now regard it as generically distinct. 



1 . Wilmattea minutiflora. 



Hylocereus minutiflorus Britton and Rose, Contr. U. S. Nat. Herb. 16: 240. 19 13. 

 Cereus minutiflorus Vaupel, Monatsschr. Kakteenk. 23: 86. 1913. 



A slender, high-climbing vine, the joints 3-angled, deep green, the angles sharp but not winged, 

 not horny-margined; areoles 2 to 4 cm. apart; spines usually 1 to 3, minute, brownish; flowers only 

 5 cm. long, opening at night, rarely remaining open until 9 o'clock in the morning, very fragrant; 

 flower-tube only 10 mm. long, or even less; outer perianth-segments linear, red on the midvein and 

 at the tip, 3 to 4 cm. long; inner perianth-segments very narrow, acute, white; stamens white, about 

 1 cm. long, borne in a series at the base of the inner perianth-segments; scales on the ovary some- 

 times bearing bristles in their axils, sometimes naked, oblong to ovate, purple or greenish at base; 

 style white, 2 cm. long, thick; stigma-lobes white. 



Type locality: Near Lake Izabel, Guatemala. 

 Distribution: Guatemala and Honduras. 



A cutting of the plant developed 3 thin wings 10 mm. wide, the areoles producing 2 

 to 5 long white hairs but no spines. In all the young joints 5 to 8 wings started, but all but 



