Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

Click images to enlarge and show more photo credit.

Key to Crocanthemum

Cistaceae

Crocanthemum

Copy permalink to share

(c) Sorrie, Bruce A. - CC-BY
1 Leaf undersurface not readily obscured by pubescence (the abaxial leaf surface visible); leaves basally disposed, the largest of which generally rounded in shape (obovate to elliptic) and present in the basal rosette
1 Leaf undersurface densely stellate-pubescent, the hairs concealing the abaxial leaf surface; leaves not basally disposed and plants not mat-forming (except sometimes in C. rosmarinifolium, but its leaves are linear-lanceolate and also with prominent abaxial pubescence).
(c) Finzel, Brian - CC-BY-SA
    3 Inflorescence a terminal umbellate cluster; chasmogamous capsules 3-valved; stems 5-15 (-20) cm tall, decumbent to ascending
(c) Bradley, Keith
    3 Inflorescence a thyrse, the flowers borne in clusters in the axils of leaves; chasmogamous capsules 2-valved; stems 20-35 (-41) cm tall, ascending to erect
      4 Leaves 1-4 (-7) mm wide, (5-) 7-15× as long as wide; capsules glabrous, those from chasmogamous flowers 2-3 mm long, with 1-3 (-6) seeds, those from cleistogamous flowers 1.3-1.7 mm long, with 1 (-2) seeds; plants sometimes mat-forming with prominent basal leaves
      4 Leaves 2-20 mm wide, 2-6 (-8)× as long as wide; capsules from chasmogamous flowers (2.4-) 3-9 (-10.5) mm long, with 6-92 (-135) seeds; capsules from cleistogamous flowers 1.5-4.2 mm long, with 1-20 seeds; plants not mat-forming nor with prominent basal leaves.
        5 Chasmogamous flowers usually solitary or 3, terminal or subterminal, later overtopped by lateral branches; seeds papillate, 35-53 per chasmogamous capsule, 5-14 per cleistogamous capsule; chasmogamous capsules 4-7 (-8.5) mm long, cleistogamous capsules (2-) 2.3-4.5 mm long; upper surface of outer sepals with some long simple trichomes mixed with the shorter stellate trichomes; stems usually red, at least in part.
          6 Mature stems with ascending branches; adaxial leaf surface of mid-stem leaves with moderate stellate pubescence (the hairs somewhat spaced and thus epidermis still visible); seeds with long, slender papillae; [widespread in e. US]
          6 Mature stems with widely divergent branches; adaxial leaf surfaces of mid-stem leaves with dense stellate pubescence (hairs so dense, obscuring the epidermis); seeds with broad, low papillae; [rare, Long Island n. to MA]
        5 Chasmogamous flowers usually (1-) 2-18, rarely overtopped by lateral branches (often 1-3 in cymes in H. georgianum); seeds smooth or reticulate, 12-35 per chasmogamous capsule, 1-20 per cleistogamous capsule; chasmogamous capsules (2.4-) 3.5-5.7 mm long, cleistogamous capsules 1.5-4.2 mm long; upper surface of outer sepals with short stellate trichomes only; stems usually green to brown or tan.
             7 Chasmogamous and cleistogamous flowers borne together, the two types of flowers open at the same time (Mar-Jun); seeds smooth, 15-35 per chasmogamous capsule, 4-20 per cleistogamous capsule; outer sepals of the cleistogamous flowers 1.4-3.0 mm long; inner sepals of the cleistogamous flowers 2.0-4.8 mm long; [of the outer Coastal Plain (primarily barrier islands) of NC and SC].
               8 Flowers borne in dense many-flowered flat-topped cymes terminating the stem and sometimes also the main branches; capsules of the cleistogamous flowers 1.6-3.8 mm long, with 4-8 (-10) seeds; pedicels and calyx with 0.5-1.5 mm long simple trichomes mixed with the shorter stellate trichomes; outer sepals of both chasmogamous and cleistogamous flowers with an expanded, obtuse, spatulate tip, 0.3-1.2 mm wide
               8 Flowers borne in loose 1-7-flowered cymes or racemes at the ends of the main branches; capsules of the cleistogamous flowers 3.0-4.2 mm long, with 12-20 seeds; pedicels and calyx with short stellate pubescence only; outer sepals of both chasmogamous and cleistogamous flowers linear, 0.2-0.5 mm wide
             7 Chasmogamous and cleistogamous flowers borne in separate inflorescences, the chasmogamous flowers opening earlier (Apr-Jul) than the cleistogamous flowers (Jun-Sep); seeds reticulate, 12-26 per chasmogamous capsule, 1-2 (-3) per cleistogamous capsule; outer sepals of the cleistogamous flowers 0.2-1.2 (-1.8) mm long; inner sepals of the cleistogamous flowers 1.7-2.5 (-3.0) mm long; [of the Mountains and less commonly the Piedmont of NC and VA, and very rarely the Coastal Plain of VA].
                 9 Stems mostly 20-50 cm tall, clustered, arising from an upright caudex; distinct portion of the outer sepals of the cleistogamous flowers linear, (0.3-) 0.6-1.2 (-1.8) mm long, about 3-5× as long as wide; distinct portion of calyx of the chasmogamous flowers (2.4-) 3.5-4.5 (-8) mm long; cleistogamous capsules sharply 3-angled in cross-section; leaf with broadly cuneate base
                 9 Stems mostly 10-30 cm tall, scattered, arising from horizontal elongate rootstocks; distinct portion of the outer sepals of the cleistogamous flowers rudimentary, knob-like, 0.2-0.5 mm long, 1-2× as long as wide; distinct portion of calyx of the chasmogamous flowers (0.7-) 1.5-3.0 (-4.0) mm long; cleistogamous capsules somewhat rounded in cross-section; leaf with narrowly cuneate to attenuate base