Sphagnum sect. Subsecunda
green to dark brown, superficial cortex of 0–3 layers of efibrillose, non-ornamented, enlarged, thin-walled cells;
cells in outer layer aporose or with single round to elliptical wall thinning adjacent to the distal cell wall, visible only with heavy staining.;
stem leaves varying from smaller than to larger than branch leaves;
triangular, ovate to lingulate;
with rounded and sometimes erose apex;
border entire;
hyaline cells rhomboid to S-shaped, non-ornamented, efibrillose to fibrillose, aporose to sometimes porose, non- to multiply septate;
neither surface resorbed.
not always clearly dimorphic, spreading and pendent branches very similar.
oval, ovate or ovate-lanceolate;
hyaline cells fibrillose, non-ornamented;
convex surface mostly with numerous elliptical to round pores (8–24 per cell) in rows along commissures on convex surface, concave surface with fewer or no pores; chlorophyllous cells elliptical in transverse section, ± equally exposed on both surfaces or slightly more on convex surface, end walls not thickened.
dioicous.
with few pseudostomata.
22–41 µm, with or without raised surface sculpture on distal surface;
proximal laesura more than 0.5 spore radius.
fascicles 1–3 spreading and 0–2(–4) pendent.;
branch stems green, surrounded by 1 layer of efibrillose, non-ornamented, thin-walled, inflated cells, with solitary short-necked retort cells or with conspicuously necked retort cells, interspersed with primarily aporose rectangular-shaped cells.
Sphagnum sect. Subsecunda
Species 99 (13 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Stem cortex undifferentiated, superficial layer composed of small thick-walled cells | S. microcarpum |
1. Stem cortex differentiated with one or more superficial layers of enlarged thin-walled cells | → 2 |
2. Stem cortex of more than 1 superficial layer of enlarged, thin-walled cells | → 3 |
2. Stem cortex 1 superficial layer of enlarged, thin-walled cells | → 7 |
3. Stem leaves broadly ovate and completely fibrillose, fascicles of 3 branches; terminal bud large, round. | S. platyphyllum |
3. Stem leaves lingulate and fibrillose apically; fascicles most 4 or more branches; terminal bud, if any, small | → 4 |
4. Stem leaf hyaline cells without parallel septations, usually non-septate; branch leaves 1.2-2 mm. | S. contortum |
4. Stem cortex partly one and partly two layers of enlarged thin-walled cells | → 5 |
5. Branch leaf convex surface commissural pores equal to or less than 1 µm. | S. orientale |
5. Branch leaf convex surface commissural pores 3 µm or more | → 6 |
6. At least some stem leaf hyaline cells with 2 or more parallel septations; branch leaves 2.2 mm or longer. | S. carolinianum |
6. Stem leaf hyaline cells without parallel septations, leaves less than 2.2 mm | S. inexspectatum |
7. Stem simple without branches | → 8 |
7. Stems with branches arranged in fascicles | → 9 |
8. Hyaline cells of stem and branch leaves with numerous minute, rounded pores on free surface, stem and branch leaves similar and very long (3.5-4 mm), some stem cortical cells with a single wall thinning at the distal end of the cell. | S. cyclophyllum |
8. Hyaline cells of stem and branch leaves without pores on superficial surface or with 1-3 small pores in apical ends and angles of cells, stem leaves longer (1.5-2.5 mm) than branch leaves (0.9-1.2 mm), stem cortical cells aporose. | S. pylaesii |
9. Hyaline cells of branch leaves without pores on convex surface or with 1-3 small pores in cell apical ends and angles, hyaline cells of branch leaves with thick fibrils that nearly divide the cells into a series of squarish segments. | S. pylaesii |
9. Hyaline cells of branch leaves with rows of commissural pores or with 1-5 pores per cell free from the commissures on the convex surface, hyaline cells with thin fibrils | → 10 |
10. Stem leaves greater than 1.2 mm, lingulate to ovate-lingulate, generally fibrillose for more than 1/3 their length. | S. lescurii |
10. Stem leaves equal to or less than 1.2 mm, triangular to triangular-lingulate, generally fibrillose for 1/3 or less their length | → 11 |
11. Branch leaf hyaline cells lacking pores along the commissures but up to 5 small pores free from the commissures on convex surface. | S. oregonense |
11. Branch leaf hyaline cells with continuous rows of pores along the commissures and sometimes with few to numerous pores free from the commissures on convex surface | → 12 |
12. Branch leaf hyaline cell pores less than or equal to 3 µm, often with 1- 2 rows of pores free from the commissures. | S. perfoliatum |
12. Branch leaf hyaline cell pores more than 3 µm, lacking pores free from the commissures | → 13 |
13. Stem leaves longer than 0.7 mm; branch leaves equal to or greater than 1.2 mm, mostly straight. | S. inundatum |
13. Stem leaves less than 0.7 mm; branch leaves less than 1.2 mm, often subsecund. | S. subsecundum |
