Terrestrial or epiphytic shrub with stems to 5 m;  mature branches terete, striate, or ribbed, glabrous, or puberulent and glabrate, brown to reddish-brown; twigs subterete to bluntly angled, striate or ribbed, puberulent or rarely densely short-pilose.  Leaves elliptic, lance-elliptic, or ovate, (2.5-)5-7.5(-11) x (1-)1.5-3(-4.5) cm, basally rounded or obtuse, rarely subcordate, apically usually short-acuminate, rarely long-acuminate, apex itself usually blunt, rarely subacute, glabrous to moderately pilose on both surfaces often glabrate;  3-5-plinerved from near base, midrib and inner pair of lateral nerves impressed above and raised beneath, outer pair of lateral nerves slightly raised on both surfaces, reticulate veinlets raised above but obscure beneath;  petiole subterete, angled, rugose, 4-8 mm long and 1-2 mm diam., pilose to glabrate.  Inflorescence (11-)16-30(-40)-flowered, oblong inflorescence bracts rarely persisting at base;  rachis subterete, angled, striate or ribbed, glabrous to coarsely short-pilose, (2.5-)6-11.5(-14.5) cm long and 1-1.5 mm diam., the proximal 1-1.5 cm often with sterile nodes, with or without glandular fimbriae;  floral bracts caducous, oblong to obovate, 5-8 x 3.5-4 mm, apically rounded, marginally glandular-fimbriate, pale green to yellowish-green often suffused with purple when fresh;  pedicels subterete, striate, glabrous to short-pilose, often glandular-fimbriate, 5-13 mm long (to 15 mm after anthesis) and 0.4-0.5 mm diam.;  bracteoles located near base, ovate, 0.4-0.5 mm long, apically rounded, pilose, marginally glandular-fimbriate with fimbriae 0.4-0.5 mm long and distinct, or fimbriae stout and fusing distally.  Flowers:  calyx glabrous or pilose, often glandular-fimbriate, 4-5.5 mm long;  hypanthium cylindric or cylindric-campanulate, smooth or bluntly pentagonal, 1.3-1.6 mm long, basally rounded, subtruncate, or with a smooth apophysate rim, slightly to conspicuously constricted at junction with limb, pale green when fresh;  limb cylindric-campanulate or spreading, 2.5-4 mm long, often tinged with purple or red when fresh;  lobes separate or imbricate at anthesis, ovate, oblong-ovate, or triangular, cuspidate or acute, 1-1.5 mm long, connivent or twisting-connivent around style base after anthesis, purplish or red when fresh, marginally with slender or stout glandular fimbriae, the distal ones sometimes fusing, or each side of margin provided with a more or less crescent-shaped to oblong callose gland and this sometimes with 1-2 fimbriae near sinus;  sinuses none (when lobes imbricate) to narrowly U-shaped, obtuse, or broadly rounded;  corolla cylindric to cylindric-urceolate, constricted at base and throat, glabrous or distally pilose, 8-12 mm long and 4-5 mm diam. at broadest part (constricted to 2.5 mm near base), when fresh shiny translucent white at base (sometimes in lower half) and violet to burgundy-red in upper half, lobes deltoid, obtuse, 1 mm long, reflexed at anthesis, when fresh reddish without and pinkish within;  stamens 6.3-8.6 mm long;  filaments distinct or rarely connate in lower half, weakly short-pilose in middle ventrally, alternately 1.5-2.5 mm and 2.5-3.5 mm long;  anthers alternately 5-7 mm and 4.3-5.6 mm long;  thecae alternately 2-2.5 mm and 1.5-2.3 mm long;  style 10-11 mm long, sometimes exserted.  Berry 7-9 mm long, insipid (fide Camp E-1702).

    Distribution (Map).  Eastern foothills of the Andes in Ecuador and at the Cerros del Sira (Huánuco, Peru);  900-2225 m.

 Key to Varieties of Cavendishia isernii

1.  Calyx lobes marginally glandular-callose, separate (not imbricate);
     hypanthium basally apophysate with a smooth rim ................ var. isernii
1.  Calyx lobes marginally glandular-fimbriate, often imbricate; hypanthium
     basally rounded or truncate ....................................  var. pseudospicata
 

Cavendishia isernii Sleumer var. isernii.  Images: Color slide, flowering inflorescence.  Line-drawing.

    Inflorescence (including rachis, pedicels, calyces, and corollas) glabrous and without glandular fimbriae (or fimbriae rarely located at junction of pedicel and calyx).  Calyx with hypanthium basally apophysate, the apophysis margin smooth and slighlty flaring;  lobes triangular, acute, at anthesis widely separate, marginally glandular callose with each side provided with a crescent-shaped gland and sometimes also bearing 1-2 fimbriae near sinus;  sinuses acute or broadly rounded.

    Distribution (Map). Known from the eastern foothills of the Ecuadorian Andes in the vicinity of Cosanga (Napo Prov.), where it occurs in disturbed forest areas at elevations of 1375-2225 m, and also in eastern Peru at the Cerros del Sira (Huánuco Dept.) in dense elfin and cloud forest at 1585-2205 m.

    Uses:  Cultivated at ABG, E, NCSC, NY.
 

Cavendishia isernii Sleumer var. pseudospicata (Sleumer) Luteyn, Fl. Neotrop. Monogr. 35: 110, fig. 46C-E.  1983.  Cavendishia pseudospicata Sleumer, Bot. Jahrb. Syst. 71: 406.  1941.  Type.  Ecuador.  Pastaza:  Mera, 1100 m, 1 Mar 1956 (fl), Asplund 19530 (neotype, designated by Luteyn (1983), NY;  isoneotypes, B, G, K, L, LD, S, UPS, Z).  The holotype specimen (Schultze-Rhonhof 2619) at B was destroyed.  Images:  Color slide, fruiting inflorescences.  Line-drawing.

    Inflorescence (including rachis, pedicels, calyces, and corollas) glabrous or pilose, also usually provided with glandular fimbriae.  Calyx with hypanthium basally rounded, subtruncate, or rarely with a minute rim, slightly constricted at junction with limb; lobes ovate, oblong-ovate, or triangluar, cuspidate or acute, at anthesis imbricate, contiguous, or separate (then often imbricate when in bud or just prior to anthesis), marginally with distinct glandular fimbriae or the distal ones rarely fusing;  sinuses none (when lobes imbricate) to narrowly U-shaped or obtuse.

    Distribution (Map).  Known only from the "Oriente" of Ecuador around Mera and Puyo (Pastaza Prov.), where it occurs in forest, marshy areas, and along steep roadcut slopes of the eastern foothills at elevations of 900-1100 m.