| | 1. Upper heads in loose groups of 3–5 subtended by 1–4 leaves, length 2+ × width; inner chaff scales 0.3–0.4 × head, tip included, ± erect; lower heads ± = upper |
| H. sparsiflora |
| | 2. Longest leaves 6–12(14) mm, ± round, densely woolly |
| var. brevifolia |
| | 2' Longest leaves (10)13–30 mm, ± obovate, cobwebby |
| var. sparsiflora |
| | 1' Upper heads in dense groups of 1–40 subtended by 6–20 leaves, length < 1.5 × width; inner chaff scales 0.5–1 × head, tip exserted, spreading; lower heads 0 or < upper |
| |
| | 3. Longest leaves generally 33–90 mm; petiole > 2 × blade; heads in groups of 10–40, largest group > 9 mm wide; chaff scales in 5 vertical ranks |
| H. caulescens |
| | 3' Longest leaves < 32 mm; petiole < 1.5 × blade; head generally 1, sometimes 2–8 in group < 8 mm wide; chaff scales in spiral ranks |
| H. acaulis |
| | 4. Stem ± erect; longest leaves 9–32 mm, 2–5 mm wide; inner chaff scales 2.5–3.2 mm |
| var. robustior |
| | 4' Stem ± prostrate or 0; longest leaves generally 4–12 mm, < 2 mm wide; inner chaff scales 1.6–2.4 mm |
| |
| | 5. Leaves ± sessile, oblanceolate, acute, longest generally 7–12 mm |
| var. acaulis |
| | 5' Leaves petioled, ± round, obtuse, longest generally 4–7 mm |
| var. ambusticola
|