1958] 



THE BOTANY OF THE GUAYANA HIGHLAND PART III 



91 



maturity. In general appearance and in characters of the pubescence, however, 

 the collection by Schultes and Lopez strongly suggests its affinity with the other 

 collections of M. sum ma. 



Marlierea summa var. superior McVaugh. var. nov. 



A var. summa foliis obtusis vel obtuse breviacuminatis, 1.7-2.4-plo longioribus 

 quam latioribus differt. 



Leaves ovate or elliptic, 2-4 cm wide, 5-8.5 cm long, 1.7-2.4 times as long as 

 wide, obtuse or bluntly short-acuminate, obtuse or rounded at the base, the mar- 

 gins abruptly decurrent on the stout channeled petiole 2-2.5 mm thick, 4-5 mm 

 Long; lateral veins slightly raised and apparent on both surfaces; both surfaces 

 thickly but finely and inconspicuously punctate; panicles 3-7.5 cm long, the 

 lowest branches up to 2 cm long, the peduncle stout, compressed, 1.5-5 cm long, 

 up to 2.5 mm wide at summit ; petals 5. 



VENEZUELA: Bolivar: Ilu-tepui, Gran Sabana, mesa ridge at 1900 m elevation, March 

 14, 1952, Ma (j Hire 33405 (MICH, type), Maguire 33378 (MICH). 



39. Marlierea umbraticola (H.B.K.) Berg, Linnaea 27: 17. 1855. 



Myrtns umbraticola H. B. K. Nov. Gen. & Sp. 7: 258 (folio ed. 199). 1825. 

 Marlierea insculpta Diels, Verh. Bot. Ver. Brandenb. 48: 188. 1907. 



For description see Berg in Mart. Fl. Bras. 14 1 : 35 (1857). Amazonian Bolivia 

 and Brazil to eastern Colombia (the type from Maypures on the Rio Orinoco) 

 and southern Venezuela. 



VENEZUELA: Amazonas: Esmeralda, upper Orinoco, elevation 130 in, May 18, 1942, 

 L. Williams 15483 (F). Solano, lower Rio Casiquiare, elevation 102 m, March 12, 1942, 

 Williams 14777 (F). Costa poblada del Cano Macasi, Capihuara, alto Rio Casiquiare, eleva- 

 tion 120 m, May 27, 1942, Williams 15592 (F). Puerto Ayacucho, elevation ca. 100 m, May 

 1931, Holt §• Blalce 801 (F, US). Locality uncertain: In Vasiva Lacus ripis, Jan 1854, Spruce 

 3316 (K). 



A collection from Maroa, Rio Guainia, Amazonas. Venezuela, elevation 127 

 m, L. Williams 14420, 11-2-19-12 (US . probably represents an undescribed spe- 

 cies of Marlierea, but the material is insufficient for positive identification. The 

 specimen bears nearly mature fruits, which have persistent on them the irregu- 

 larly broken calyx-margins, and the inflorescence appears to be that of Marlierea. 

 The plants are nearly glabrous but bear the remains of what was apparently a 

 sparse appressed pubescence of long pale hairs; the leaves are large and coarse. 

 7-10 cm wide, 16-20 cm long or more, on petioles 2 mm in diameter, 12-15 mm 

 long ; the midvein is convex above ; the panicles are 12 cm long, many-flowered ; 

 the lateral veins are well differentiated, 12-15 pairs prominent beneath ; the 

 marginal vein is 3-7 mm from margin. The plant suggests M. macrophylla in 

 many respects, but the petioles are longer and the leaves narrowly rounded at 

 the base and the pubescence is of longer hairs. In the absence of flowers, and 

 without the presence of more distinctive characters of leaves and pubescence, it 

 would be premature to describe this as a new species. 



