1. Plants without chlorophyll, mycotrophic; pollen in monads ..............
..................................................... Monotropa uniflora
1. Plants with chlorophyll, autotrophic; pollen in tetrads.
2. Plants with ± herbaceous habit; embryos undifferentiated, without
developed cotyledons ........................... Chimaphila maculata
2. Plants shrub- or tree-like, with woody habit; embryos well-
developed, with cotyledons.
3. Ovary superior.
4. Corolla polypetalous; flowers 5-7(-9)-merous ...........
........................................... Bejaria aestuans
4. Corolla sympetalous; flowers 5-merous.
5. Corolla salverform, ± zygomorphic; viscin threads mixed
with pollen tetrads; fruit a septicidal capsule,
cylindrical; infrequently cultivated ...............
.................................... Rhododendron simsii
5. Corolla urceolate, cylindric-urceolate or tubular;
viscin threads absent; fruit a loculicidal capsule,
drupe, or berry; native.
6. Inflorescence terminal, often paniculate.
7. Fruit a drupe, ovule 1 per locule; leaf
length/width ratio usually greater than 3;
leaf length/petiole length ratio usually greater
than 10; leaf base cuneate; fruit dark purple
to black at maturity ........................
..... Comarostaphylis arbutoides ssp. arbutoides
7. Fruit a berry, ovules more than 1 per locule;
leaf length/width ratio usually less than 3;
leaf length/petiole length ratio usually less
than 10; leaf base usually rounded to truncate
or rarely subcordate; fruit red at maturity ...
............................. Arbutus xalapensis
6. Inflorescence axillary, racemose.
8. Stamens with filaments geniculate ..............
............... Agarista mexicana var. pinetorum
8. Stamens with filaments straight.
9. Fruit a berry, rarely calyx becoming fleshy
at base but never surrounding the berry ......
........................ Pernettya prostrata
9. Fruit a capsule, surrounded by the fleshy,
accrescent calyx .......... Gaultheria erecta
3. Ovary inferior.
10. Pedicel continuous with calyx hypanthium, not articulate;
flowers and fruits with pedicels thin and equalling or
longer than the subtending leaves.
11. Leaves suborbicular to oblong-ovate, (7-)9-15(-18) mm
long; stamens 4 ............. Sphyrospermum buxifolium
11. Leaves ovate to lance-ovate, (15-)20-50(-70) mm long;
stamens 4-10 and generally 4-5 or 8-10 ...............
............................ Sphyrospermum cordifolium
10. Pedicel articulate with calyx hypanthium; flowers and
fruits with pedicels short and thick, much shorter than
subtending leaves.
12. Stamens with filaments and anthers of equal lengths.
13. Corolla cylindric-campanulate, 8-12 mm long,
yellowish-green, sometimes rose apically; anther
thecae flexible, smooth; anther tubules flexible
.............................. Vaccinium poasanum
13. Corolla tubular, elongate-cylindric, (12-)18-25
mm long, red or orange, the apex whitish or
greenish, respectively; anther thecae rigid and
conspicuously papillose; anther tubules rigid.
14. Leaves plinerved or nearly so; staminal
filaments connate; anther thecae dehiscing
through one pore ........ Macleania insignis
14. Leaves conspicuously pinnate-nerved; staminal
filaments distinct; anther thecae dehiscing
through two pores ...... Macleania rupestris
12. Stamens with filaments or anthers or both unequal,
obviously of two lengths.
15. Staminal filaments connate, of equal lengths;
floral bracts small, green, not showy.
16. Corolla inconspicuously but densely short-
pilose, red but apically green; calyx lobes
trucately rounded and apiculate ............
......................... Satyria panurensis
16. Corolla glabrous or essentially so, red but
apically pinkish to white; calyx lobes
triangular and acute.
17. Corolla 10-12(-15) mm long; calyx
hypanthium ca. 2 mm diam. at anthesis,
minutely puberulous .. Satyria meiantha
17. Corolla (14-)17-28 mm long; calyx
hypanthium ca. 3-4 mm diam. at anthesis,
glabrous ......... Satyria warszewiczii
15. Staminal filaments distinct, alternately unequal;
floral bracts large, red, showy.
18. Leaves subsessile, amplexicaul, ovate to
semiorbicular ..............................
... Cavendishia complectens ssp. complectens
18. Leaves obviously petiolate, not amplexicaul,
ovate to lance-elliptic.
19. Rachis elongate, to 13 cm long, with
20-35 flowers; calyx lobes completely
glandular callosed ....................
.................. Cavendishia callista
19. Rachis short, (0.7-)1.5-2(-3) cm long,
with (4-)6-20 flowers; calyx lobes
eglandular or the margins glandular-
fimbriate ....... Cavendishia bracteata |