11. Disterigma (KLOTZSCH) NIEDENZU Bot. Jahrb. Syst. 11: 160, 209 (1889).

-- Lectotype: Disterigma empetrifolium (H.B.K.) DRUDE.

Vaccinium sect. Disterigma KLOTZSCH, Linnaea 24: 57 (1851).

Vacciniopsis RUSBY, Bull. Torrey Bot. Cl. 20: 433 (1893). -- Type: Vaccinium ovata RUSBY

[=Disterigma ovatum (RUSBY) S. F. BLAKE].

Killipiella A. C. SMITH, J. Washington Acad. Sci. 33(8): 242 (1943). -- Type:

Killipiella styphelioides A. C. SMITH.

Reference: SMITH, A. C., The genera Sphyrospermum and Disterigma . Brittonia 1(4): 203--232 (1933). -- SLEUMER, H. O., Ericaceae americanae novae vel minus cognitae, I. Notizbl. Bot. Gart. Berlin-Dahlem 12 (112): 119--140 (1934). -- SMITH, A. C., Killipiella , a new Colombian genus of Vacciniaceae. J. Washington Acad. Sci. 33(8): 242--244 (1943). -- WILBUR, R. L., A synopsis of the genus Disterigma (Ericaceae: Vaccinieae) in Mexico and Central America with the description of two previously undescribed species. Bull. Torrey Bot. Cl. 119(3): 280--288 (1992).

Compact bushy to straggly, terrestrial or epiphyte shrubs. Leaves alternate, coriaceous, often congested, usually less than 3 cm long, margin entire or crenate, usually obscurely plinerved, short-petiolate. Inflorescence axillary, of solitary or 1--6-clustered, subsessile flowers, subtended by a few, minute, subcoriaceous bracts; pedicel short or lacking; bracteoles apical along pedicel, immediately subtending calyx hypanthium. Flowers (3-) 4 (-5)-merous, without odor; aestivation valvate (or calyx rarely imbricate); calyx obscurely articulate with the pedicel and embraced by the closely subtending bracteoles; hypanthium campanulate to short cylindric; lobes suberect; corolla subcylindric or campanulate-cylindric, (3-) 4--5-lobed; stamen equal, (5--6) 8, usually twice as many as the corolla lobes but rarely of the same number as the lobes; filaments distinct, ligulate, longer or shorter than anthers, lacking spurs; anthers dorsally attached near the base, membranous, lacking disintegration tissue; thecae smooth; tubules (1-) 2 and dehiscing by elongate, elliptical, introrse clefts or subterminal pores; pollen lacking viscin threads; ovary inferior, (3-) 4 (-5)-locular; style filiform and about as long as the corolla; stigma truncate; nectariferous disc fleshy, annular-pulvinate. Fruit a berry, thick-walled, coriaceous, blue-black or translucent white; seeds sometimes mucilaginous.

Disterigma is a small genus of about 35 species ranging from the highlands of Guatemala south to Bolivia and east to Guyana.

1a.

Stamen 5.

2a.

Flowers surrounded by a series of numerous, persistent, ovate to ovate-lanceolate bracts to 7 mm long; calyx lobes narrowly lanceolate, ca 3.5 mm long; bracteoles ovate-lanceolate, long-acuminate, ca 7 mm long; S Bolívar-Chimborazo provinces (ca 2% S latitude) and south

............................................................................................D. pentandrum

2b.

Flowers surrounded by a series of few, caducous, ovate bracts to 2 mm long; calyx lobes deltate, ca 1 mm long; bracteoles oblong to lanceolate, obtuse to acute, ca 1--2 mm long; Imbabura to S Bolívar provinces (but N of 2% S latitude)

............................................................................................D. rimbachii

1b.

Stamen 8 or 10, double the number of corolla lobes.

3a.

Anther tubules fused into 1

...........................................................................................D. utleyorum

3b.

Anther tubules 2, separate not fused.

4a.

Corolla campanulate-rotate.

5a.

Corolla 3.6--6 mm long, white to greenish.

6a.

Corolla 5--6 mm long, white; leaves 10--15 x 5--8 mm, the apex obtuse or rounded

..............................................................D. campii

6b.

Corolla 3.6--5 mm long, green; leaves 3.8-7.5 x 1.7--5 mm, the apex acuminate to short-cuspidate

..............................................................D. microphyllum

5b.

Corolla 7--10 mm long, red to greenish-red.

7a.

Leaves elliptic-oblong, 6.5--9 x 3--4 mm, the apex rounded, the margin entire; twigs pilose-strigose; bracteoles 1.5--2 mm long; calyx hypanthium sharply 4-angled, 1.5--2 mm long, the lobes 1.5--2 mm long; staminal filaments 2--2.5 mm long

..............................................................D. dumontii

7b.

Leaves ovate-oblong, 5--11 x 1.5--5 mm, the apex acute to subacute, the margin crenate; twigs short-pilose or hispidulous; bracteoles 3.5--5 mm long; calyx hypanthium terete, 2--2.7 mm long, the lobes 2.5--3 mm long; staminal filaments 3.5--5 mm long

..............................................................D. codonanthum

4b.

Corolla cylindric to cylindric-urceolate.

8a.

Apex of leaves acuminate or conspicuously cuspidate.

9a.

Corolla 4.5--8 mm long; leaves 0.5--1.2 x 0.3--0.7 cm; bracteoles 2--3 mm long, surrounding only the lower half of the calyx hypanthium or sometimes up to the tips of the calyx lobes

..............................................................D. acuminatum

9b.

Corolla (6-) 8--11 mm long; leaves 1.2--2.5 x 0.5--1.6 cm; bracteoles 5--7 mm long, completely surrounding and concealng the entire calyx and lower half of the corolla at anthesis

..............................................................D. cryptocalyx

8b.

Apex of leaves rounded, obtuse or acute, (rarely in D. alaternoides acuminate but then > 1 cm broad).

10a.

Corolla 3.5--6 mm long.

11a.

Leaves linear-oblong to elliptic-oblong, 3.3--10 x 0.7--2 mm; calyx lobes tufted-setose at tips; corolla red, 5--6 mm long; stamen exserted at anthesis

.....................................................D. agathosmoides

11b.

Leaves elliptic to ovate-subrotund, 5--10 x 3--5 mm; calyx lobes glabrous; corolla white, 3.5--4.3 mm long; stamen inserted at anthesis.

12a.

Leaves narrowly elliptic, 8--10 mm long; bracteoles enclosing only calyx hypanthium; corolla cylindric-urceolate, distally inflated

..........................................D. micranthum

12b.

Leaves ovate-subrotund, 4--5.5 mm long; bracteoles enclosing all the calyx and the lower half of the corolla; corolla narrowly cylindric, not inflated

.........................................D. noyesiae

10b.

Corolla 6 mm long or more.

13a.

Corolla densely and persistently puberulent to pilose.

14a.

Leaves ovate, 0.6--1.3 x 0.4--0.6 cm; corolla 11--13 mm long, red

.........................................D. balslevii

14b.

Leaves elliptic, (1.1-) 1.5--2.2 x 0.8--1.5 cm; corolla ca 9--9.5 mm long, white

.........................................D. leucanthum

13b.

Corolla glabrous (or essentially so).

15a.

Calyx 7.3--8 mm long, the lobes obovate-elliptic, apiculate, narrowly imbricate, ca 5 mm long

.........................................D. stereophyllum

15b.

Calyx < 5 mm long, the lobes triangular-deltate, separate, ca 2.5 mm long or less.

16a.

Leaves mostly greater than 5 mm broad.

17a.

Leaf apex acute or very rarely slightly acuminate

...................D. alaternoides

17b.

Leaf apex rounded.

18a.

Flowers sessile; corolla 9--11 mm long; calyx lobes 2.5--3 mm long, ciliate

..........D. ecuadorense

18b.

Flowers with pedicel to ca 2 mm long; corolla 4.5--6 (-8) mm long; calyx lobes 1.5--2 mm long, not ciliate

..........D. humboldtii

16b.

Leaves equal to or mostly less than 5 mm broad.

19a.

Leaves ovate, elliptic, or rarely orbicular, 4--7 (-9) mm broad; corolla white to pinkish

...................D. humboldtii

19b.

Leaves linear to narrowly elliptic, or oblong- to elliptic-lanceolate, 1.3--5 mm broad; corolla red, white, or pale yellowish-green.

20a.

Corolla red; leaves 4.5--12 mm long; plants growing from montane cloud forest to superpáramo, at 2865--4350 m altitude

..........D. empetrifolium

20b.

Corolla white to pale yellowish-green, often with pink or red lobes; leaves (0.8-) 13--20 mm long; plants growing in pluvial forest (in Ecuador), at 650--750 m altitude

..........D. pseudokillipiella