Ericaceae-Neotropical Blueberries
James L. Luteyn and Paola Pedraza-Peñalosa
The New York Botanical Garden

SPHYROSPERMUM

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Key to Species

 

     Sphyrospermum is a genus of about 21 species of terrestrial and epiphytic shrubs found in lowland to high montane rainforest habitats from southern Mexico through the highlands of Central America and the Andes of South America to Bolivia, east through the Guianas, and in the Caribbean from Haiti to Trinidad.  The center of diversity is found in Colombia and Ecuador.  The genus is characterized by small and obscurely nerved leaves, solitary or paired sympetalous flowers on usually cernuous pedicels, inferior ovaries, calyces continuous with the pedicels, staminal filaments usually longer than anthers, lacking spurs and usually somewhat sigmoid at the base, anther tubules distinct and as long as or longer than the thecae with dehiscence by short, oval clefts, and berry fruits which when immature are dry and brittle.   The relationships of Sphyrospermum should be sought with Diogenesia and Themistoclesia;  all three genera have in common corollas usually thin and small, immature fruits that are thin and brittle, and seeds with green embryos. Sphyrospermum differs from Themistoclesia primarily by its terete not angled calyx, and from Diogenesia by its fewer flowers on slender, cernuous pedicels and by filaments longer than anthers. Sphyrospermum has only been treated in its entirety by Smith (1933b) and that treatment is very much out of date.  The only other major work is that of Luteyn (1996b) in which the 16 species occurring in Ecuador were revised.

     Most of the species of Sphyrospermum (ca. 12-15 spp.) are extremely rare having only been collected once or a few times;  this fact makes the genus a "troublesome" one.  The genus as a whole, as well as most of the species, must be considered in extreme danger of extinction, because the localities and habitats in which they have been found are all undergoing severe alteration.

 

SPHYROSPERMUM Poeppig & Endlicher, Nov. gen. sp. pl. 1: 4, pl. 8.  1835.  Lectotype:  Sphyrospermum buxifolium Poeppig & Endlicher.
 

Sophoclesia Klotzsch, Linnaea 24: 15, 29.  1851.  Type:  not cited.


     Slender, often straggly, epiphytic or terrestrial shrubs with pendent branches.  Leaves alternate, coriaceous, sometimes very thickly so, often brittle, usually small and obscurely nerved, subsessile.  Inflorescence axillary, flowers solitary or rarely paired in axils of the leaves;  pedicel slender, cernuous, distally swollen;  bracteoles 2, deciduous.  Flowers 4-5--merous, without odor;  aestivation apparently valvate; calyx continuous with the pedicel;  hypanthium subglobose or obconic; limb suberect; corolla campanulate, cylindric (tubular), to infundibuliform;  stamen usually as many or twice as many as the corolla lobes, equal or alternately slightly unequal; filaments distinct, usually longer than anther, lacking spurs, usually somewhat sigmoid at the base; anther inserted dorsally near base, membranous, smooth, lacking disintegration tissue;  tubules distinct, as long as or longer than the thecae, dehiscing by oval clefts; pollen lacking viscin threads;  nectariferous disc annular-pulvinate, but not readily apparent;  ovary inferior, 4-5--locular, the partitions soon decaying; stigma truncate;  style filiform, about as long as corolla.  Fruit a subglobose or ellipsoid, juicy berry, topped by the persistent calyx limb and lobes, translucent white to lavender or purplish, glabrous or pubescent, when immature the pericarp dry and brittle, when mature thin and papery;  ovules numerous, the placentation axile but often appearing central or even basal;  seeds elongate, striate, the embryo green and clearly visible through the endosperm.  Chromosome number:  2n=48, 96, ca. 130 (Atkinson et al., 1995).

Key to Neotropical Species                                                                                               Back to Top

1.  Corolla tiny, less than 4 mm long.
     2.  Stamen 4;  leaves suborbicular-elliptic, (1.5-)2-4 cm long;  pedicel 5-9 mm long.
          3.  Leaves suborbicular-elliptic, 2-4 cm long; pedicels 5-7 mm long;  calyx
               hypanthium terete, densely villose;  corolla 3.5 mm long, weakly pilose ........
               ......................................................................................................  S. ellipticum.
          3.  Leaves ovate to lance-ovate, 4.5-6 cm long;  pedicels 7-15 mm long;
               calyx hypanthium slightly 4-angled, glabrous but glandular-fimbriate;
               corolla 2-2.3 mm long, glabrous (?) ................................................  S. standleyi.
     2.  Stamen 8-10;  leaves orbicular to ovate-elliptic, 0.5-1.3 x 0.4-0.8 cm;
          pedicel to 4 mm long.
          4.  Flowers 5-merous, subsessile, pedicel less than 1 mm long;  corolla hispid
               in distal 1/2-1/3, cylindric-campanulate, the throat open and spreading;
               leaves 10-13 x 6-8 mm  ...........................................................  S. spruceanum.
          4.  Flowers 4-merous, obviously pedicellate, pedicel 3-6 mm long;  corolla
               glabrous, cylindric, the throat narrowed and contracted;  leaves 5-8 x 4-6
               mm long  ................................................................................  S. microphyllum.
1.  Corolla larger, equal to or greater than 4 mm long (if 4 mm long, then pedicel
     > 15 mm long).
     5.  Corolla campanulate, the throat broad and spreading.
          6.  Corolla yellow, ca. 5-5.5 mm long;  anther tubules much longer than
               thecae, dehiscing by oblique, subterminal pores  ..........................  S. flaviflorum.
          6.  Corolla dark red, 8.5-12 mm long;  anther tubules equal to or shorter
               than thecae, dehiscing by perfectly terminal pores.
               7.  Flowers 4-merous;  pedicel 1-4(-8) mm long;  leaves apically acute
                    to rounded;  anther tubules about equalling thecae, ca.1.6-2.5 mm long;
                    berry quadrangular  ..................................................................  S. dissimile.
               7.  Flowers 5-merous;  pedicel 10-15 mm long;  leaves apically obtuse-
                    mucronate;  anther tubules < thecae, ca. 0.5-0.6 mm long;  berry ellipsoid
                    .......................................................................................  S. campanulatum.
     5.  Corolla cylindric to cylindric-urceolate or cylindric-infundibuliform, the
          throat obviously contracted.
          8.  Corolla equal to or greater than 12 mm long, the lobes strongly reflexed at
               anthesis so as to expose stamens (mature corolla unknown in S. musicola).
               9.  Leaves pellucid, veinlets clearly visible, very acute at apex, about as long
                    as broad, 20-30 x 20-23 mm;  stamen 10, with filaments slightly longer
                    than anthers;  calyx lobes ca. 1.5 mm long, tufted-pilose at tip;  pedicel
                    15-20 mm long;  corolla red, pilose distally, 12-20 mm long  ...  S. musicola.
               9.  Leaves coriaceous, opaque, veinlets obscure, long- to short-acuminate
                    at apex, noticeably longer than broad;  stamen 8-10, with filaments
                    about two times anther length.
                    10.  Leaves narrowly ovate-lanceolate, very long-acuminate;  flowers
                           5-merous;  E Ecuador ................................................  S. lanceolatum.
                    10.  Leaves ovate to broadly ovate, short- to long-acuminate;
                           flowers 4-merous;  W Ecuador.
                           11.  Leaves 1-3.5(-4.3) x 0.5-1.5(-1.8) cm;  corolla infundibuliform,
                                  moderately to densely short-hirsute;  filaments 13-15 mm long,
                                  densely pilose;  flowers conspicuously extending beyond the
                                  subtending leaf;  calyx densely to sparsely puberulent ... S. boekei.
                           11.  Leaves (2.6-)3-7(-8.5) x (1.6-)2.5-3.5 cm;  corolla tubular,
                                  broadened above middle, usually glabrous;  filaments 9-15 mm
                                  long, usually glabrous;  flowers not extending beyond but instead
                                  usually slightly hidden by the subtending leaves;  calyx usually
                                  glabrous  ............................................................  S. grandifolium.
          8.  Corolla equal to or less than 12 mm long, the lobes not so strongly reflexed
               as to expose stamens at anthesis.
               12.  Pedicel 0-10 mm long, the flowers ± hidden by the leaves.
                      13.  Pedicel none, the flowers sessile.
                             14.  Leaves distichous, 6-11 x 4-9 mm, ovate with the apex
                                    obtuse to acute;  corolla 5 mm long, pilose in distal half;
                                    twigs hispid with ferrugineous hairs;  Colombia  ..... S. distichum.
                             14.  Leaves spirally arranged, 15-21 x 4-6 mm, lanceolate with
                                    the apex acuminate;  corolla 8.5-10 mm long, weakly pilose;
                                    twigs densely white pilose;  Bolivia ...................  S. sessiliflorum.
                      13.  Pedicel 4-10 mm long, the flowers pedicellate.
                             15.  Calyx lobes 2-2.5 mm long;  corolla pubescence glandular  .....
                                    .................................................................................  S. buesii.
                             15.  Calyx lobes equal to or less than 1 mm long;  corolla glabrous
                                    or if pubescent, then the hairs non-glandular.
                                    16.  Corolla tubular, broadest above the middle, 9-12 mm
                                           long, hispid, red with lobes blue-black (even when dry);
                                           leaves 1-3 cm long, succulent and brittle when fresh but
                                           drying thin-coriaceous with the lower surface strongly
                                           wrinkled;  calyx hispid, the lobes acuminate, 0.6-0.8 mm
                                           long;  stamen alternately unequal, the filaments longer than
                                           anthers, 5.5-7.5 mm long ..................................  S. sodiroi.
                                    16.  Corolla urceolate, ca. 6 mm long, glabrous, pale yellow,
                                           the lobes not black;  leaves (2-)2.5-4 cm long, succulent
                                           when fresh and drying thick-coriaceous, concave, often
                                           revolute, and with the midrib often strongly carinate;
                                           calyx short white pilose to villous, the lobes deltate,
                                           short-acuminate, 0.6-1 mm long;  filaments shorter than
                                           anthers, 1-1.5 mm long ...................................  S. haughtii.
               12.  Pedicel (10-)12-25 mm long.
                      17.  Leaves suborbicular, (0.7-)0.9-1.5(-1.8) cm long, the apex
                             rounded;  flowers extending well beyond the leaves; mature
                             corolla 4-5.5 mm long (rarely 6 mm), white to pinkish;
                             stamens 4 .................................................................  S. buxifolium.
                      17.  Leaves ovate to ovate-lanceolate, usually conspicuously longer
                             than broad, (1-)2-13 cm long, the apex obtuse to sharply long-
                             acuminate;  flowers rarely extending beyond the leaves;  mature
                             corolla 5-12 mm long (rarely less), white to dark red;  stamens
                             4-5 or 8-10.
                             18.  Leaves ovate-lanceolate, (8-)10-13 x 4-5 cm, the apex
                                    (usually sharply) long-acuminate;  corolla ca. 9.5 mm long;
                                    stamens 10  ......................................................  S. longifolium.
                             18.  Leaves broadly to narrowly ovate, (1-)2-3.5(-5) x (0.8-)
                                    1.5-6 cm, the apex obtuse to long-acuminate;  corolla
                                    (4-)5-12 mm long;  stamens 4-5 or 8-10.
                                    19.  Leaves 4-6 x 1.2-2 cm, the apices long-acuminate;
                                           corolla 10-12 mm long;  stamens 8 or 10;  staminal
                                           filaments glabrous;  Peru .........................  S. weberbaueri.
                                    19.  Leaves (1-)1.5-3.5(-5) x 0.7-2.5(-3) cm, the apex
                                           obtuse or rounded to acute, sometimes shortly and
                                           bluntly acuminate;  corolla (4-)5-8(-9) mm long;
                                           stamens 4-5 or 8-10;  staminal filaments glabrous or
                                           pilose.
                                           20.  Flowers glabrous or more normally pilose;  fruits
                                                  globose to thickly fusiform, to15 mm diam;
                                                  Mexico to Bolivia, E to the Guianas and
                                                  Hispaniola ........................................  S. cordifolium.
                                           20.  Flowers glabrous;  fruits ellipsoid, 4-6 mm long
                                                  and 2.5-4 mm broad.
                                                  21.  Corolla 5-6 mm long, bright yellow, densely
                                                         pilose within;  filaments about equal to the
                                                         anthers and callose-thickened at base;
                                                         Colombia ...........................  S. munchiqueensis.
                                                  21.  Corolla ca. 8 mm long, white, glabrous within;
                                                         filaments longer than anthers and not basally
                                                         callose-thickened;  Mt. Roraima, Venezuela ...
                                                         .............................................  S. klotzschianum.
 

                       A species of uncertain status keys here:  Sphyrospermum tuberculatum
                       Wilbur & Luteyn (perhaps it is just S. cordifolium, but with tuberculate
                       calyces.

 

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