Citation: J.L. Drumm. ex Harvey, Hooker's J. Bot. Kew Gard. Misc. 7:56 (1855).

Derivation: Greek dicroos, forked; stylos, style; alluding to the deeply 2-branched style.

Synonymy: Not Applicable

Common name: Sand-sages.

Description:
Perennial shrubs or undershrubs, densely clothed with a cotton-woolly branched indumentum; stem erect, branched, cylindrical; leaves sessile or petiolate, decussate or verticillate, simple, exstipulate, entire or crenate, flat or with recurved to revolute margins.

Inflorescence terminal, cymose; cymes pedunculate or sessile, arranged in corymbose (W.Aust. species), pyramidal or spicate panicles, or the cymes sessile, congested to form decussate or verticillate clusters; flowers 5-merous, bracteate, sessile or pedicellate; calyx tubular, mostly 5-lobed, rarely with more or fewer than 5 lobes, densely tomentose outside, glabrous inside; corolla tubular, mostly 5-lobed, rarely with more or fewer than 5 lobes, pubescent outside, villous inside the tube, lobes entire or crenate at the apex; stamens 5, rarely fewer or more than 5, inserted in the corolla tube, exserted or scarcely protruding; anthers 2-lobed, dorsifixed, lobes non-appendiculate, more or less oblong, free and divergent in the lower half, longitudinally dehiscent; ovary 4-celled, with 1 ovule in each cell; ovules attached at or above the middle of the cell; style deeply 2-branched, exserted or scarcely so.

Fruit dry, indehiscent, 1- or 2-seeded; seeds albuminous.

Distribution:  About 26 species all endemic to Australia. (Munir (1978) Brunonia 1:437-567.)

Biology: No text

Key to Species:

1. Cymes sessile, in distant verticillate clusters; bracts somewhat larger than the cymes, 4-8 x 2-5 mm; lowest corolla lobes much larger than the others	D. verticillata 8.
1. Cymes pedunculate or sessile, opposite; bracts much smaller than the cymes, 1-4 x 0.5-3 mm; corolla lobes equal or almost so
2. Leaves sessile or almost so, linear, linear-lanceolate, or narrowly elliptic-lanceolate, 2-8 (rarely 10) mm broad, with margins recurved-revolute or almost flat (in D. doranii)
3. Cymes in subglobose clusters; calyx hairy on the upper half inside; corolla purplish-blue, lobes entire; stamens and style much exserted	D. lewellinii 6.
3. Cymes more or less pyramidal or in an elongated terminal spike- like panicle, with a few branches or peduncles near the base of the spike; calyx glabrous inside; corolla white or yellow, lobes crenate; stamens and style scarcely exserted
4. Inflorescence and shoot-tips with a golden-yellow tomentum
5. Leaves and calyx thin-tomentose; flowers more or less lax in clusters; clusters non-globose, close together on a slender rhachis	D. beveridgei var. beveridgei 1a.
5. Leaves and calyx thick-tomentose; flowers congested, almost hidden under the woolly tomentum; clusters subglobose, distant from each other on the thick rhachis	D. beveridgei var. lanata 1b.
4. Inflorescence and shoot-tips with a whitish-grey, purplish-violet or purplish-grey tomentum
6. Leaves narrowly ellipfic-lanceolate, cuneate towards the base, flat or almost so; mature cymes arranged in a more or less pyramidal panicle	D. doranii 3.
6. Leaves linear or linear-lanceolate, with margins recurved-revolute; cymes in an elongated terminal spike-like panicle
7. Inflorescence and shoot-tips with a whitish-grey tomentum	D. costelloi var. costelloi 2a.
7. Inflorescence and shoot-tips with a purplish-violet or purplish-grey tomentum
8. Cymes more or less globular, with a purplish-grey tomentum	D. costelloi var. globulifera 2b.
8. Cymes more or less ovoid, not globular, with a purplish-violet tomentum	D. costelloi var. violacea 2c.
2. Leaves petiolate, elliptic-ovate, lanceolate or ovate-lanceolate, 10-30 mm broad, with margins always flat
9. Cymes mostly sessile or a few basal ones with short peduncles, arranged in decussate clusters forming a terminal spike-like inflorescence, with a greenish-grey or creamy tinged with a yellow tomentum	D. petermannensis 7.
9. Cymes mostly pedunculate, arranged in more or less pyramidal panicles, with a golden-yellow, greyish-orange or purplish-grey tomentum
10. Inflorescence with a golden-yellow or greyish-orange tomentum; flowers not forming head-like clusters
11. Leaves lanceolate, dark-green to dark-brown above; branchlets hairy but not tomentose; calyx tomentum 0.5-1 mm thick, non-woolly; calyx lobes distinct; inflorescence more or less lax	D. exsuccosa var. exsuccosa 4a.
11. Leaves ovate-lanceolate, brownish-yellow; branchlets densely tomentose; calyx tomentum 1-2.5 mm thick, very woolly; calyx lobes hidden under the woolly tomentum, inflorescence more or less congested	D. exsuccosa var. tomentosa 4b.
10. Inflorescence with a purplish-grey or a greenish-grey tomentum; flowers congested into head-like woolly clusters
12. Cyme peduncles in the lower half of an inflorescence 1-2.5 (rarely 3.5)cm long, the terminal ones often in the axil of leafy bracts	D. gilesii var. gilesii 5a.
12. Cyme peduncles in the lower half of an inflorescence 2-4.5 (rarely 5.5)cm long, the terminal ones often in the axil of non-leafy bracts	D. gilesii var. bagotensis 5b.

Author: Not yet available