Perennial or sometimes annual geophytes or hemicryptophytes, unarmed, terrestrial, with raphides in the tissues, often with well developed ropy taproots. Leaves opposite or occasionally subopposite, petiolate to sessile, entire or 2--3-lobed, sometimes with lower cauline and uppermost leaves differing in form, with higher-order venation not lineolate, without domatia, often with main veins subpalmate; stipules interpetiolar and fused to petioles, triangular, acute to bilobed or erose or setose, with form often irregular along a stem, apparently imbricated in bud, persistent. Inflorescences terminal, subcapitate to shorty cymose, 1--several-flowered, subsessile to pedunculate, bracteate with bracts often foliaceous and 3--7-lobed. Flowers subsessile, bisexual, distylous, fragrant, diurnal, medium-sized; hypanthium turbinate to ellipsoid; calyx limb deeply 2--5-lobed, trianglar to stipitate, sometimes with 1--15 bright yellow or pink calycophylls; corolla salverform, yellow and/or pink, internally glabrous, dimorphic with tube cylindrical in short-styled form and swollen in upper part in long-styled form, lobes 5, triangular, valvate in bud, without appendages; stamens 5, inserted in upper part of throat of corolla tube, anthers narrowly oblong, basifixed, opening by longitudinal slits, without appendages, included or exserted; ovary 2-locular, each locule divided by 1 pseudoseptum, with ovules 2 per locule and 1 on each side of the pseudoseptum, axile, stigmas 2, included or exserted. Fruit capsular, subglobose to ellipsoid or ovoid, chartaceous to papyraceous, loculicidally dehiscent into 2--5 valves, with calyx limb persistent; seeds 2-4, ellipsoid to ovoid, smooth or verrucose, with one medial sulcus, black or brown.

Key to Oreopolus and Cruckshanksia

1. Leaves opposite or occasionally subalternate; stipules triangular to bilobed or erose, usually separated along the stems due to good development of the internodes that separate the leaves; calyx lobes not enlarged or often one or several of them prolonged into white or colored, petaloid appendages (i.e., calycophylls); capsules dehiscent from the base into 2-5 valves...Cruckshanksia

 1. Leaves ternate or occasionally opposite; stipules triangular and usually imbricated due to the limited development of the internodes, so the leaves are hardly separated; calyx lobes never enlarged into petaloid appendages; capsules dehiscent from the apex into 2 valves...Oreopolus

Key to the Species of Cruckshanksia

1. Calyx lobes equal, none bearing petaloid appendages or all the lobes bearing them, thecalyx lobes elliptic to oblanceolate or with stipitate, elliptic to ovate petaloid appendages (i.e., calycophylls) in flower, these appendages sometimes becoming orbicular to broadly elliptic in fruit.

     2. Leaf blades 15-40 mm long, sharply acute at apex; stipules 1.5-2 mm long; calyx lobes in flower 10-15 mm long, in fruit 12-23 mm long, without stipes...C. palmae

      2. Leaf blades 8-20 mm long, obtuse to rounded at apex; stipules 0.8-1.6 mm long; calyx lobes in flower 3.5-11 mm long (including stipe, when present), in fruit 7-17 mm long, elliptic to oblanceolate, and without stipes, or 10-15 mm long and with stipes.

         3. Calyx lobes in flower all composed of stipes 3-6 mm long bearing elliptic to ovate appendages 3-5 mm long, in fruit the stipes 10-15 mm long with the appendages ovate and 9-13 mm long....C. lithiophila

    4. Plants annual or perhaps sometimes perennial; corolla lobes 1-2.5 mm long; corolla tube 0.1-0.3 mm in diameter near its middle...C. pumila

    4. Plants perennial; corolla lobes 2-4.5 mm long; corolla tube 0.3-1 mm in diameter near its middle.

        5. Petaloid calyx lobe appendages pink or white (though frequently drying yellow); leaves 2-15 mm wide...C. hymenodon

         5. Petaloid calyx lobe appendages yellow; leaves 0.8-6 mm wide.

            6. Cauline leaves simple or sometimes 3-lobed; petaloid calyx lobe appendages 6-10 x 8-15 mm in flower, to 12 x 18 mm in fruit... C. montiana

             6. Cauline leaves simple to usually 2-3-lobed; petaloid calyx lobe appendages 3-6 x 2-7 mm in both flower and fruit.....C. verticillata