Monographs Details: Bonnetia sessilis Benth.
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Theaceae
Scientific Name:Bonnetia sessilis Benth.
Description:Distribution and Ecology - Distribution. A shrub or small tree of middle and upper altitudes of the Gran Sabana of Venezuela, the Pakaraima Plateau of Guyana, the disjunct mesas of western Bolívar, Venezuela, and mesetas of adjacent Brazil. VENEZUELA. Edo. Bolívar: Roraima, 1842-3, Schomburgk 636 (NY, W); Schomburgk 1046 (holotype K); Auyán-tepuí at 1850 m alt, Jan 1938, Tate 1162 (NY); arbustillo 2 m, hojas carnosas, brilliantes, Cerro Akurimá, Sta. Elena, Feb 1946, Tomayo 2700 (US); arbusto 3 m, Alto Caroni, alrededores de Sta. Elena, 19 Abr 1946, Lasser 1352 (NY, VEN); Kavanayen at 1300 m, 27 May 1946, Lasser 1720 (NY, VEN); orillas del río Uaiparú, arbol 16 m, fl blancas, 27 Oct, Cardona 1918; Auyán-tepuí, 1500 m, 21 May 1937, Cardona 65 (US); Auyán-tepuí, Cardona 218 (US); shrub 3 m, 1760 m alt, Cerro Guaiquinima, 15 Jul 1944, Cardona 1118 (US); orillas del Río Caroní at 720 m, arbor 6 m, fl blanca, 8 Oct 1946, Cardona 1753 (NY, VEN); Makauyén, 1040 m, Gran Sabana, 16 Oct 1946, Cardona 1856 (US); arbusto 4 m, fl blancas, 900 m alt, 22 Oct 1946, Cardona 1882 (US); arbol 6 m, flores blancas, cumbre Cerro Arepuchi, 5 Nov 1946, Cardona 1942 (NY, VEN, US); arbusto 1 m, Uaipán at 1200 m, 25 Nov 1946, Cardona 2005 (NY, VEN, US); arbusto 2 m, in sabanas, 1100 m, Cerro Upuima, Oct 1947, Cardona 2220 (US); arbusto de 6 m, fl blancas, Cerro Acopan at 850 m, Oct 1947, Cardona 2222 (NY, VEN, US); shrub 1-2 ft high, 1700 m, abundant, Uaipán-tepuí, 1-15 Feb 1948; Cerro Auyán, Enero 1949, Cardona 2633 (NY, VEN); Phelps & Hitchcock 344 (NY, VEN); common shrub 3-5 ft tall, Kavanayen at 1220 m, 26 Oct 1944, Steyermark 59340 (NY, F); Kavanayén, 30 Nov, Steyermark 60821 (NY, F); shrub 10-15 ft, petals white, Apácara-tepuí at 415 m, 29 Mar 1953, Steyermark 74691 (NY, VEN); tree 3-4 m, Sierra Ichura, Río Parágua at 600-700 m, 27 Dec 1961, Steyermark 90228 (NY, VEN); Auyán-tepuí at 1700-2100 m, 1 May 1964, Steyermark 93207 (NY, VEN); Meseta de Jaua, at 400 m, 17-29 Mar 1967, Steyermark 98215 (NY, VEN); Aprado-tepuí at 900-1000 m, 15-18 Agosto 1953, Bernardi 798 (NY, VEN); Icabarú, 450-850 m, 15 Enero 1956, Bernardi 2612 (NY, VEN); 21 Abr 1957, Bernardi 6671 (NY, VEN); Canaima, Nov 1958, Aristeguieta 3782 (NY, VEN); Auyán-tepuí, Abr 1956, Foldats 2630 (NY, VEN); Uaipán-tepuí, 4 Mar 1967, Agostini & Koyama 7463 (NY, VEN); Cerro Guaiquinima, Río Parágua: shrub to 2 m, frequent, rim and savanna along west escarpment at 1800 m, 30 Dec 1951, Maguire 32828 (NY); 25 Dec 1951, Maguire 32767; small tree or shrub 2-3 m high, North Valley at 1700 m, 2 Jan 1952, Maguire 32906 (NY); 4 Jan 1952, Maguire 32999 (NY); bushy tree 2-8 m, petals white, margins pink, common in savanna, thickets, and bush islands, Mesa Grande at 1600 m alt, Ilu-tepuí, Gran Sabana, 12 Mar 1952, Maguire 33358 (NY); Kavanayén at 1300 m, 4 Apr 1952, Maguire 33737 (NY). GUYANA. Pakaraima Plateau: 2500 ft, between Ireng and Cotinga Rivers, im Thurn No. 11, Oct-Jan in 1884-85, (US); tree 4 m, Kaieteur Savanna at 400 m alt, 6 Jan 1944, Maguire & Fanshawe 23258 (NY); shrub or small tree to 2 m, Imbaimadai Savanna, 22 Oct 1951, Maguire & Fanshawe 32175 (NY); shrub 1-2 m high, Samwarakua-tepu (Holi-tipu) at 1100 m, 10 Nov 1951, Maguire & Fanshawe 32498 (NY); tree 6 m high, Kamarang Station at 500 m alt, 13 Nov 1951, Maguire & Fanshawe 32605 (NY); Chinowieng, at 600 m alt, Feb 1955, Maguire, Bagshaw & Maguire 40616 (NY); shrub or small tree to 5 m high, savanna adjacent to Partang Rapids, Partang River, Merume Mountains, at 470 m alt, 23 Jun 1960, Maguire & Maguire 45912 (NY). BRAZIL. Terr. Roraima: shrub 1-2 m high, petals white, style branches 1 mm long, Serra Tepequem at 4000 ft alt, 27-29 Dec 1954, Maguire & Maguire 40372 (NY); common on sandstone hills south of Cajú at 1000 m alt, 3 Jan 1955, Maguire & Maguire 40477 (NY).

Discussion:

Kieseria sessilis (Benth.) O. Kuntze, Rev. Gen. PI. 1: 62. 1891.

Bonnetia phelpsii Gleason, Brittonia 3: 170. 1939. Type. Auyan-tepui at 1100 m alt, 7 Dec 1937, G. H. H. Tate 1158 (holotype NY).

Type. Roraima mountains, Schomburgk 1046 (holotype K).

Bonnetia sessilis is the common species at middle altitudes, being less abundant upwards but reaching an altitude exceeding 2000 m. Next to B. paniculata it has the widest distribution of all other species of the genus. It seems to be the eastern correlative of B. crassa, which occupies middle and higher altitudes in western Guayana.

Distribution:Venezuela South America| Guyana South America| Brazil South America|