Other pleurocarps

(If you need to know what a pleurocarp is, click here)
A Brachythecium

B Other or unknown— 1

1 Plant aquatic, growing submerged in streams, rivers or lakes — 2

Plant not aquatic — 3

2 Leaves long (5 mm.), keeled, strictly in 3 ranks — Fontinalis antipyretica

Leaves much shorter (1.5-2.5 mm.), not keeled nor strictly 3-ranked — Eurhynchium riparioides (Cf. also nearly straight-leaved forms of Cratoneuron filicinum which are commonly found submerged in streams in limestone country.)

3 Secondary shoots somewhat tassel-like or resembling miniature trees, with erect or ascending, almost bare ‘main stem’ and crowded branches above — 4

Plants lacking this dendroid or sub-dendroid habit.

4 Stems thick, rigid and dark red or blackish green, unbranched for several centimetres, so that the habit is markedly dendroid (tree-like) — 5

Stems thin, weak and green in colour, with some branches almost to base, so that habit merely sub-dendroid (not quite tree-like) or tassel-like — 6

(N.B. A plant of bushy habit, with rigid, erect, red stems branched from the base, and leaves up to 3-5 mm. long will probably be Rhytidiadelphus triquetrus.)

5 Stems short, erect, 2-5 cm. tall; leaves 2-3 mm. long, bright yellowish green and glossy; looking like' miniature palm trees' in moist grassy places — Climacium dendroides

Stems longer (5-12 cm.), sub-erect or arched; leaves about 1 mm. long, dull dark green; on shaded rocks, often by waterfalls — Thamnium alopecurum = Thamnobryum alopecurum

6 Branch leaves finely drawn out at tips so that branches appear slender and acutely pointed; capsules curved, inclined — Isothecium myosuroides

Branch leaves shortly pointed only, so that branches usually appear relatively stout and bluntly pointed; capsules straight, erect —Isothecium myurum = Isothecium alopecuroides

7 Main branches regularly bipinnate or tripinnate in one plane, hence frond-like — 8

Main branches simple or once pinnate only — 9

8 Stems red, not rigid; leaves glossy, pale or dull yellowish green — Hylocomium splendens

Stems green or blackish, rigid; leaves not glossy, vivid green or yellow-green — Thuidium tamariscinum

(N.B. A plant with weak green stems that appears to 'key out' here will probably be Eurhynchium praelongum, luxuriant forms of which are sometimes mistaken for Thuidium tamariscinum.)

9 Stems red or orange-red — 10

Stems green or yellowish — 14

10 Leaves straight, with very short points or rounded at apex, appressed or slightly spreading; branching usually very regularly pinnate — 11

Leaves curved, with broad bases and long acute tips which are widely spreading .or recurved; branching most often irregular (sometimes pinnate) —12

11Uppermost leaves rolled together (even when wet) forming sharp 'spear-head' (cuspidate) shoot tips, lower leaves widely spreading, in marshes — Acrocladium cuspidatum

'Spear-head' shoot tips normally lacking (at least when wet), lower leaves not widely spreading; chiefly heath and moorland — Pleurozium schreberi

12 Leaves at shoot tips large (3-5 mm.), clear pale green, only lightly curved; branches short and crowded above, so that habit bushy (stems often nearly erect) — Rhytidiadelphus triquetrus

Leaves at shoot tips shorter, dull yellowish green, widely spreading-recurved; branches long and never crowded, so that habit not as above —13

13 Plant robust, with strong, rigid, freely branched stems; leaves curved gradually from base to long, fine, hook-like tip; upland woods and mountain slopes — Rhytidiadelphus loreus

Plant of medium size, with relatively weak, little-branched stems; leaves abruptly bent outwards (squarrose) above short clasping bases, divergent tips straight and scarcely hook-like; grassy places (very common generally) — R. squarrosus

14 Semi-aquatic: in marshes or on rocks or tree bases by water — 15

Not semi-aquatic; habit various — 19

15 Uppermost leaves rolled together to form very sharp, 'spear- head' shoot tips — Acrocladium cuspidatum

(Cf. also Brachythecium rivulare and nearly straight-leaved forms of Cratoneuron filicinum, both of which can appear to have these 'spear-head' shoot tips at times; they will, however, be instantly separated under the microscope.)

Uppermost leaves widely spreading in conspicuously star-like manner — Campylium stellatum

Shoot tips neither forming sharp 'spear-heads' nor star-like —16

16 Leaves small (about 1 mm.), nerveless; secondary stems with long slender branches; yellowish green to bright golden plant of rocks by waterfalls and mountain streams — Hyocomium armoricum

Leaves larger (1.5-2.5 mm.), nerved; secondary stems with relatively short branches; various shades of green —17

17 Leaves ovate and shortly pointed; plant deep green; older stems often nearly bare of leaves; always by or in running water — Eurhynchium riparioides

Leaves narrower, with rather long fine points; plant yellowish or mid-green; older stems not bare of leaves — 18

18 Secondary stems with numerous short, nearly erect branches; leaves crowded and not widely spreading; tips of branches light yellowish green and very glossy — Brachythecium rivulare

Habit usually creeping, with irregular or pinnate branching; leaves rather distantly spaced and widely spreading; tips of branches darker green and not very glossy Leptodictyum riparium

19 Leaves minute (0.5 mm.), only just distinguishable with the naked eye — Amblystegium serpens

Leaves larger (1 mm. or over), easily seen with the naked eye — 20

20 Leaves bluntly rounded, or suddenly contracted into minute points (apiculate) at tips — 21

Leaves gradually tapering to acute points — 23

21 Leaves opaque, not glossy, much shrivelled and curled when dry; plant of calcareous banks —Anomodon viticulosus

Leaves translucent, glossy, little altered when dry; habitats various — 22

22 Uppermost leaves rolled together to form sharp, 'spear-head' shoot tips; colour usually vivid yellowish green — Acrocladium cuspidatum

‘Spear-heads’ lacking, shoot tips appearing blunt and rounded; branchlets swollen with concave leaves; usually pale yellowish green — Pseudoscleropodium purum

23 Plant with numerous fine branches on which the leaves are much smaller than on the main stems; forming untidy, usually deep green straggling mats on shaded banks — Eurhynchium praelongum

Plant lacking these very fine, small-leaved branches, being less intricately branched; with leaves nearly equal in size throughout shoot — 24

24 Leaves narrowly lanceolate, tapering gradually to rather long fine tips, usually 2-2.5 mm. long; plants with strikingly silky gloss — 25

Leaves (on main secondary stems) ovate-lanceolate to heart- shaped, often shorter, rather suddenly narrowed above the middle to form fairly short fine points; dull or glossy — 26

25 Bright green, with silky sheen, creeping on walls, boulders or tree bases — Camptothecium sericeum

Yellowish, of loose habit with ascending branches; in calcareous grassland or sand dunes — Camptothecium lucens

26 Robust; leafy shoots 2 mm, across, leaves 1.5-2.5 mm. long and 1 mm. broad at base — 27.

Slender; leafy shoots 1 mm. across, leaves distinctly smaller than above — 28

(N.B. A plant intermediate in size between 27 and 28, with numerous erect, little-branched, glossy, yellow-green secondary shoots, growing on poor sandy or gravelly soil, will probably be Brachythecium albicans (Brachythecium key) ).

27 Stems and branches rather rigid so that big bushy tufts formed; leaves evenly and widely spreading when dry; stem leaves heart- shaped to triangular, with strong longitudinal striations (folds); capsule lid long-beaked; calcareous woods and banks — Eurhynchium striatum

Stems creeping with soft, irregular ascending branches, bushy tufts, not formed; leaves less regularly and widely spreading when dry, broadly ovate-lanceolate and only faintly striate; lid of capsule not long-beaked; abundant in woods, etc. — Brachythecium rutabulum (Brachythecium key)

28 Very silky; capsule lid not long-beaked; on stones, etc., in light or shade — Brachythecium velutinum (Brachythecium key)

Not very silky; capsule lid long-beaked; on stones, etc., chiefly in shady situations — Eurhynchium confertum

(N.B. Straight-leaved varieties of Hypnum cupressiforme and small forms of Isothecium myosuroides may key out here, but will require a microscope for determination.)

Pseudosclerapodium purum


For comments about this site please mail to:

(e-mail address given as graphic to avoid spam)