The Manual of the Botany of the Northern United States / Including the District East of the Mississippi and North of North Carolina and Tennessee

by Asa Gray

17. Ledum. Corolla regular, all 5 petals nearly separate. Stamens 5–10. Leaves evergreen.

[*][*] Anther-cells opening lengthwise. Leaves evergreen. Bud-scales firm and persistent.

18. Leiophyllum. Corolla of 5 separate petals. Stamens 10, exserted.

19. Loiseleuria. Corolla deeply 5-cleft. Stamens 5, included.

Suborder III. Pyroleæ. (Pyrola Family.) Calyx free from the ovary. Corolla polypetalous. Anthers extrorse in the bud, opening by pores at the base (inverted in the flower). Seeds with a loose and translucent cellular coat much larger than the nucleus.

Tribe I. CLETHREÆ. Shrubs or trees, with deciduous foliage (in ours). Pollen-grains simple. Capsule 3-celled.

20. Clethra. Sepals and petals 5. Stamens 10. Style 3-cleft at the apex.

Tribe II. PYROLEÆ. Herbs or nearly so, with evergreen foliage. Pollen-grains compound. Capsules 5- (rarely 4-) celled.

21. Chimaphila. Stems leafy. Flowers corymbed or umbelled. Petals widely spreading. Style very short and top-shaped. Valves of the capsule smooth on the edges.

22. Moneses. Scape 1-flowered. Petals widely spreading. Style straight, exserted; stigma 5-rayed. Valves of the capsule smooth on the edges.