Leaves mostly opposite or subopposite, usually paler on lower surface; petiole commonly very short.
Inflorescence mostly a terminal raceme, sometimes on short lateral branches, spike-like, often condensed into heads or clusters, with or without bracts forming an involucre. Flowers mostly bisexual, sometimes unisexual; pedicel usually short. Hypanthium tubular with 4 usually spreading sepal lobes. Petals absent. Stamens 2, inserted in the hypanthium and mostly exceeding it. Ovary with 2 carpels, but only 1 functional with a solitary ovule; style lateral.
Fruit mostly a 1-seeded nut or rarely drupaceous; fruit usually ± narrow-ovoid, frequently glabrous except for a few hairs at the apex, mostly green or brown at maturity, sometimes red, rarely black.
Some species are known to be toxic to stock, and others are suspected of being so. Known toxic species include P. curviflora, P. flava, P. glauca, P. linifolia, P. microcephala, P. neo-anglica, P. pauciflora, P. simplex and P. trichostachya. P. petrophila F. Muell. has been recorded in the Barrier Range (NFWP). This species is very similar to P. flava but differs in the narrower bracts and the pitted (not furrowed) seeds. Key based on Threlfall (1983).
| | Key to the species | |
| 1 | Stems glabrous; leaves usually glabrous, rarely hairy when very young | 2 |
| Stems hairy although sometimes glabrescent with age; leaves mostly hairy, sometimes glabrous | 18 |
| 2 | Flowers unisexual, plants dioecious; female hypanthia continued only shortly, if at all, above the ovary; hypanthia persistent or tardily circumsciss above or around the ovary after flowering | 3 |
| Flowers bisexual or in some species flowers occasionally female by abortion; hypanthia continued well above the ovary; tube circumsciss above the ovary after flowering
Back to 1 | 7 |
| 3 | Inflorescence axillary | Pimelea axiflora |
| Inflorescence terminal, sometimes borne on short lateral branches and appearing axillary
Back to 2 | 4 |
| 4 | Inflorescence entirely glabrous | Pimelea pauciflora |
| Inflorescence more or less hairy; hypanthia sometimes glabrous and then at least the pedicels hairy
Back to 3 | 5 |
| 5 | Pedicels covered with long coarse hairs; sepals and hypanthia entirely glabrous | Pimelea serpyllifolia |
| Pedicels covered, sometimes sparsely so, with short fine hairs; sepals and hypanthia glabrous on inner surface but usually bearing at least a few hairs on outer surface
Back to 4 | 6 |
| 6 | Hypanthia and sepals glabrous or sparsely hairy on outer surface; heads with 4–24 male flowers, or with 3–7, rarely to 16, female flowers | Pimelea neoanglica |
| Hypanthia and sepals with fine curly hairs on outer surface, sometimes hairs absent from tube or sepals but not both; heads with 13–100 male flowers or 7–12 female flowers
Back to 5 | Pimelea microcephala |
| 7 | Flowers in racemes, compact when young, elongated and interrupted at maturity, bracts absent | Pimelea spicata |
| Flowers in bracteate heads, in Pimelea ligustrina and P. treyvaudii the receptacle often elongates in the fruiting condition but not before the upper part of the hypanthia falls off
Back to 2 | 8 |
| 8 | Bracts completely surrounding and more or less enclosing the inflorescence, more or less broad-ovate and longer than the leaves | 9 |
| Bracts not completely enclosing the inflorescence, usually narrower, not broad-ovate and mostly shorter than leaves
Back to 7 | 10 |
| 9 | Bracts 6–8, glabrous | Pimelea bracteata |
| Bracts 4, more or less hairy on inner surface, margins of inner bracts ciliate
Back to 8 | Pimelea glauca |
| 10 | Bracts green with cream markings at the base and along midvein, 9–11 in number | Pimelea treyvaudii |
| Bracts green or with reddish markings, 4 or 8, or sometimes variable in number
Back to 8 | 11 |
| 11 | Inner bracts ciliate on the margins | 12 |
| Bracts not ciliate on the margins
Back to 10 | 15 |
| 12 | Bracts 9–13 | Pimelea ciliolaris |
| Bracts 4 or 8
Back to 11 | 13 |
| 13 | Persistent base of hypanthia glabrous | Pimelea glauca |
| Persistent base of hypanthia hairy
Back to 12 | 14 |
| 14 | Leaves 7–20 mm wide | Pimelea ligustrina |
| Leaves 1–4 mm wide
Back to 13 | Pimelea stricta |
| 15 | Leaves crowded and confined to the end of branches; flowers usually pinkish red, rarely white | Pimelea alpina |
| Leaves neither crowded nor confined to the end of branches; flowers usually white or cream, rarely pink
Back to 11 | 16 |
| 16 | Leaves mostly more than 7 mm wide with major reticulate veins as well as primary and secondary veins distinct on lower surface | Pimelea ligustrina |
| Leaves usually less than 5 mm wide (sometimes to 7 mm, with only the primary vein and rarely intramarginal veins distinct on lower surface
Back to 15 | 17 |
| 17 | Anther loculi on a broad dorsal connective and parallel on the inner face, not back-to-back when dehisced; leaves 1–4 mm wide | Pimelea stricta |
| Anther loculi on a narrow connective and back-to-back when dehisced; leaves 1–7 mm wide
Back to 16 | Pimelea linifolia |
| 18 | Inflorescence axillary | Pimelea axiflora |
| Inflorescence terminal, sometimes borne on short lateral branches and appearing axillary
Back to 1 | 19 |
| 19 | Inflorescence a raceme, usually narrow, compact when young and elongating at maturity; involucral bracts absent, apparently present in bud owing to the closeness of stem leaves | 20 |
| Inflorescence not raceme-like and usually not markedly elongating in fruit; involucral bracts present or absent
Back to 18 | 24 |
| 20 | Inflorescence remaining compact, less than 20 mm long at maturity, dense; anther connective narrow or broad, if broad then loculi parallel on the inner face | 21 |
| Inflorescence elongating to more than 20 mm at maturity, interrupted; anther connective narrow and loculi back-to-back when dehisced
Back to 19 | 23 |
| 21 | Leaves less than 20 mm long and mostly less than 5 mm wide (sometimes to 8 mm wide) | 22 |
| Leaves mostly more than 20 mm long and more than 8 mm wide
Back to 20 | Pimelea latifolia |
| 22 | Flowers greenish to white, densely covered with white spreading hairs; inflorescence terminal; peduncle and rachis densely whitish pubescent | Pimelea simplex |
| Flowers yellow tinged with red, covered with glistening more or less appressed hairs; inflorescence lateral; pedicels and young growth fawnish pubescent
Back to 21 | Pimelea strigosa |
| 23 | Flowers densely covered with short appressed hairs | Pimelea elongata |
| Flowers densely covered with long spreading hairs
Back to 20 | Pimelea trichostachya |
| 24 | Flowers in bracteate heads more than 15 mm diam.; flowers more than 10 mm long, white to creamy, at least 12 in each head, often more than 40; involucral bracts at least 4 | 25 |
| Flowers solitary or in few- to many-flowered heads or clusters, but not forming large bracteate heads more than 15 mm diam.; flowers less than 10 mm long, white to yellow-green or reddish; bracts present or absent
Back to 19 | 28 |
| 25 | Leaves mostly less than 15 mm long and less than 8 mm wide, glabrous or hairy; hairs velvety or long and white, widespread on stems, leaves and peduncles | 26 |
| Leaves mostly more than 15 mm long and more than 8 mm wide, glabrous except when very young; hairs short and fine, usually restricted to the peduncle except for a few scattered hairs for 1 or 2 nodes below inflorescence
Back to 24 | Pimelea ligustrina |
| 26 | Bracts 6–13; leaves hairy, sometimes glabrescent with age | 27 |
| Bracts 4; leaves glabrous
Back to 25 | Pimelea humilis |
| 27 | Leaves silvery, silky on both surfaces; flowers unisexual and plants dioecious | Pimelea penicillaris |
| Leaves green, usually with long white hairs at least on the lower surface but neither silvery nor silky, or more or less glabrous; flowers bisexual
Back to 26 | Pimelea ciliolaris |
| 28 | Prostrate, mat-forming shrub; leaves opposite; flowers always 2 in each head | Pimelea biflora |
| Erect plants, usually shrubs to at least 50 cm high, or occasionally erect herbs; leaves alternate to subopposite; flowers more than 2 in each head or if 2 then not consistently so, or flowers solitary
Back to 24 | 29 |
| 29 | Leaves less than twice as long as wide, often crowded and covering the stem, leaves glabrous; flowers unisexual, plants dioecious | Pimelea flava |
| Leaves not as above, usually more than twice as long as wide, scattered along stem, not completely covering it; leaves usually hairy or rarely more or less glabrous; flowers bisexual or female
Back to 28 | 30 |
| 30 | Peduncles more than 10 mm long | 31 |
| Peduncles less than 10 mm long
Back to 29 | 32 |
| 31 | Leaves usually 10–20 mm long and 3–8 mm wide; flowers yellow sometimes tinged with red | Pimelea strigosa |
| Leaves mostly 20–60 mm long, 8–20 mm wide; flowers white
Back to 30 | Pimelea latifolia |
| 32 | Leaves and stems densely hairy, with creamy soft spreading hairs, 2–4 mm long; primary and secondary veins prominent and brown | Pimelea venosa |
| Leaves and stems not usually covered with whitish spreading hairs more than 2 mm long, if leaves densely covered with spreading hairs then veins not brown and prominent
Back to 30 | 33 |
| 33 | Flowers solitary or in clusters of 2–5 in the axils of the leaves and usually accompanied by new vegetative growth; bracts absent | Pimelea umbratica |
| Flowers in few- to many-flowered terminal heads, often appearing lateral due to the outgrowth of axillary buds immediately below the inflorescence; bracts present or absent
Back to 32 | 34 |
| 34 | Flowers and fruits covered with white spreading hairs; plant herbaceous, sometimes woody at base, 15–75 cm high. Specimens of Pimelea trichostachya (sp. no. 16) bearing only young inflorescences may also key out here | Pimelea simplex |
| Flowers and fruits not covered with white spreading hairs; plants often shrubby, rarely herbaceous
Back to 33 | 35 |
| 35 | Leaves either mostly more than 2.5 mm wide and bearing short tangled spreading hairs or rarely long antrorse hairs on both surfaces, or more than 60 mm long and bearing small round projections on the upper surface (leaves 5–80 mm long) | Pimelea latifolia |
| Leaves either less than 2.5 mm wide and hairy on both surfaces, or glabrous or almost so on the upper surface and the lower surface bearing hairs that are appressed to spreading and then short and fine and slightly tangled (leaves 2–20 mm long)
Back to 34 | 36 |
| 36 | Flowers 5–12 mm long; bracts when present usually glabrous or nearly so on the upper surface, shorter than the inflorescence | Pimelea curviflora |
| Flowers 3–4 mm long; bracts when present hairy on both surfaces, at least as long as inflorescence
Back to 35 | Pimelea micrantha |
