Clethra

Linnaeus
Sp. Pl. 1: 396. 1753.
,
Gen. Pl. ed. 5. 188. 1754 ,.
Common names: Sweet pepperbush
Etymology: Greek klethra, alder, alluding to resemblance of leaves of certain species
Treatment appears in FNA Volume 8. Treatment on page 364.

Plants sometimes spreading by root suckers. Leaves spirally arranged, often seemingly verticillate at ends of twigs; blade not coriaceous, margins revolute, surfaces glabrous or tomentose abaxially, glabrous or with sparse, short-stellate hairs, especially when young, adaxially, venation pinnate. Inflorescences borne on new growth, racemes solitary or in clusters of 2–4, bracteate. Pedicels ridged and somewhat flattened laterally, 1-bracteate basally. Flowers fragrant; sepals imbricate in bud; petals spreading at anthesis, weakly 5-ridged, apex obtuse; filaments adnate to corolla basally, straight or S-shaped, elongate, glabrous or hairy; anthers reflexed in bud, erect at anthesis, obsagittate, base attenuate, papillose, thecae divergent distally; style straight. Capsules globose, sutures thin. Seeds strongly flattened, slightly winged; testa thin. x = 8.

Distribution

s, e North America, Mexico, Central America, South America, e Asia, Atlantic Islands (Madeira).

Discussion

Species ca. 65 (3 in the flora).

Selected References

None.

Key

1 Leaf blades: apex acuminate, margins toothed, proximalmost tooth averaging 2.4 cm distal to base; bracts longer than flowers; filaments glabrous or with scattered, simple hairs. Clethra acuminata
1 Leaf blades: apex obtuse to acute, margins toothed, proximalmost tooth averaging 3.4 cm distal to base; bracts shorter than flowers; filaments glabrous > 2
2 Young shoots and abaxial surface of new leaves sparsely hairy, adaxial surface glabrous; petioles 2.5-3.5(-6) cm; styles 6-7 mm, hairy in proximal 1/2, hairs simple, straight; filaments 0.2-0.3(-0.4) mm wide. Clethra alnifolia
2 Young shoots and abaxial surface of new leaves woolly-tomentose, adaxial surface sparsely hairy; petioles 0.5-1(-1.5) cm; styles 3.5-5 mm, hairy; filaments 0.4-0.5(-0.7) mm wide. Clethra tomentosa
... more about "Clethra"
Gordon C. Tucker +  and Sean C. Jones +
Linnaeus +
Sweet pepperbush +
s +, e North America +, Mexico +, Central America +, South America +, e Asia +  and Atlantic Islands (Madeira). +
Greek klethra, alder, alluding to resemblance of leaves of certain species +
Sp. Pl. +  and Gen. Pl. ed. +
Clethra +
Clethraceae +