Cardamine L.

Based on: P.B. Heenan (2020)

Cardamine reptans growing in a damp seepage on the summit of the Old Man Range, Otago. Image: Peter Heenan © Landcare Research 2019 CC BY 3.0 NZ

Classification

Class

Magnoliopsida Brongn.

Order

Brassicales Bromhead

Family

Cruciferae

Subordinate Taxa

Nomenclature

Scientific Name:

Cardamine L., Sp. Pl. 654 (1753)

Synonymy:

= Iti Garn.-Jones & P.N.Johnson, New Zealand J. Bot. 25: 603 (1987)

Description

Herbs annual or perennial. Trichomes absent or present, when present simple. Stems erect, ascending, or decumbent, sometimes rhizomatous, branched or unbranched. Basal leaves rosulate, simple, pinnatifid or pinnatisect, petiolate; lateral leaflets petiolulate, subsessile or sessile. Cauline leaves present or absent, when present alternate, simple, pinnatifid or pinnatisect as basal leaves but usually smaller and narrower. Inflorescences corymbose or racemose, flowers sometimes solitary; ebracteate, elongated in fruit. Fruiting pedicels long and slender or shorter and thickened, erect or spreading. Sepals usually saccate, margin usually membranous. Petals absent or present; when present usually white, sometimes pink or purple; claw usually differentiated from blade and longer than sepals. Filaments 6 and tetradynamous, sometimes 2 or 4 and then equal in length, linear or rarely dilated. Anthers usually yellow or sometimes maroon, glabrous, held at a similar height to stigma. Nectar glands confluent and subtending bases of all stamens. Ovules few to many. Style distinct or sometimes indistinct; stigma capitate, entire. Fruit explosively dehiscent silique or an indehiscent silicle; weakly latiseptate or ± terete, smooth or weakly torulose, sessile; valves not veined, glabrous or hairy, dehiscing elastically acropetally, coiled or indehiscent and remaining flattened; replum strongly flattened; septum complete, membranous, translucent. Seeds uniseriate, winged or wingless, flattened; seed coat minutely reticulate; embryo white, venation rarely violet-purple.

Taxonomy

Cardamine belongs to the family Brassicaceae, tribe Cardamineae, a tribe of 10 genera and over 340 species (Al-Shehbaz et al. 2006). Cardamine and Rorippa are the largest genera of the tribe, with Cardamine comprising about 230 species (Al-Shehbaz et al. 2006; Heenan 2017).

Species of Cardamine in New Zealand are morphologically diverse and offer a variety of morphological characters for taxonomic circumscription and identification (Heenan 2017). Some of the more important taxonomic characters include: leaves simple or pinnate and coriaceous or membranous, the presence or absence of leaflet axillary hydathodes, the length and width of the sepals, petals, siliques and seeds, seed size and shape, and the presence or absence of a margin wing.

Key

1	Fruit a silicle or silique, <4.0 mm long	2
	Fruit a silique, >6.0 mm long	3
2	Leaves broadly orbicular, <2.2 mm long; 2 stamens, bent at distal end; silique <4.0 mm long	cubita
	Leaves simple and linear-spathulate or pinnatifid with narrow-spathulate lobes, 20.0–50.0 mm long; 4(–6) stamens, straight; silicle <3.5 mm long	lacustris
3	Inflorescence decumbent or prostrate, axillary rosettes present in nodes	panatohea
	Inflorescence erect or spreading, axillary rosettes absent from nodes	4
4	Leaves simple with a length to width ratio of >1.5 : 1, or pinnatifid with the terminal leaflet having a length to width ratio of >1.5 : 1 and 1–4 basal lobes, usually coriaceous	5
	Leaves simple with a length to width ratio ±1 : 1 or pinnatisect with the terminal leaflet having a length to width ratio ±1 : 1 and 1–14 lateral leaflets with distinct petiolules, usually membranous	13
5	Anthers maroon or yellow and flushed maroon	6
	Anthers yellow	8
6	Sepals 0.8–1.1 mm wide; petals 4.0–7.0 mm long; silique style 0.3–0.5 mm long	dimidia
	Sepals 1.3–1.8 mm wide; petals 7.0–11.0 mm long; silique style 1.0–3.5 mm long	7
7	Leaves red-brown to brown or occasionally green; filaments linear their entire length, 0.15–0.35 mm wide; silique style 1.7–3.5 mm long	bilobata
	Leaves grey-green to green; filaments conspicuously dilated at base, 0.35–0.65 mm wide; silique style 1.0–1.2 mm long	dilatata
8	Leaves always simple	9
	Leaves simple and pinnatisect or pinnatifid	10
9	Leaves membranous, matt, up to 90 mm long, lamina obovate, elliptic, broadly elliptic, petiole up to 60 mm long; sepals 1.9–2.0 mm long; petals 2.6–4.2 mm long; filaments 1.8–2.7 mm long; siliques 7.5–8.0 mm long	alticola
	Leaves coriaceous, glossy, up to 45 mm long, lamina narrowly obovate to spathulate, petiole up to 25 mm long; sepals 1.6–1.8 mm long; petals 2.1–3.2 mm long; filaments 1.2–1.3 mm long; siliques 7.0–14.0 mm long	sciaphila
10	Leaves usually pinnatisect or pinnatifid, sometimes simple, terminal lobe or simple pinna 2–8 mm long and 0.5–5.0 mm wide; cauline leaves occasionally present, usually pinnatifid or pinnatisect; inflorescence spreading to ascending	mutabilis
	Leaves usually simple, sometimes pinnatifid, terminal lobe or simple pinna 3.0–45 mm long and 2.0–23.0 mm wide; cauline leaves usually simple; inflorescence ascending to erect	11
11	Leaves membranous, lamina surface glabrous or hairy; inflorescence usually short and held just above the leaves, flowers clustered towards distal end in a corymb; plants of Subantarctic Islands	depressa
	Leaves coriaceous, lamina surface glabrous; inflorescence usually elongated and held well above the leaves, flowers distributed along inflorescence, plants of South Island	12
12	Leaves grey-green, matt, 4.0–45.0 mm long, 2.5–23.0 mm wide; sepals 2.9–3.0 mm long; inflorescence up to 300 mm long	pachyphylla
	Leaves green, purple-brown, brown-green or bronze, glossy, 5.0–20.0 mm long, 2.0–9.5 mm wide; sepals 2.0–2.5 mm long; inflorescence up to 110 mm long	dimidia
13	Leaves with axillary hydathodes	14
	Leaves without axillary hydathodes	20
14	Siliques glabrous	15
	Siliques hairy	18
15	Leaves coriaceous, terminal leaflet 3.0–7.7 mm long and 2.8–8.6 mm wide; seed wing present, reticulate cells conspicuously thick-walled	eminentia
	Leaves membranous, terminal leaflet 3.5–21.0 mm long and 4.7–23.0 mm wide; seed wing absent, reticulate cells not obviously thick-walled	16
16	Lateral leaflets 1–2, green to dark green, with indistinct petiolules 0.2–1.5 mm long; petals broadly obovate, 4.2–4.5 mm wide; siliques 2.1–2.4 mm wide; seeds 1.0–1.2 mm wide	megalantha
	Lateral leaflets 2–8, light green to green, with distinct petiolules 2.0–20.0 mm long; petals obovate to narrowly obovate, 0.7–3.6 mm wide; siliques 0.7–1.4 mm wide; seeds 0.6–0.9 mm wide	17
17	Leaf axillary and marginal hydathodes usually associated with additional hairs; sepals 2.4–3.2 mm long; petals obovate, 4.5–8.0 mm long, 2.5–3.6 mm wide	coronata
	Leaf axillary and marginal hydathodes solitary and not associated with additional hairs; sepals 1.3–1.6 mm long; petals narrowly obovate, 2.8–4.5 mm long, 0.7–1.4 mm wide	forsteri
18	Terminal leaflet 2.6–7.0 mm long, 3.2–10.0 mm wide; lateral leaflets 2.0–5.0 mm long, 1.8–5.8 mm wide; leaflet margins entire to weakly lobed; siliques 13.0–25.0 mm long	bisetosa
	Terminal leaflet 3.5–21.0 mm long, 4.7–26.0 mm wide; lateral leaflets 2.0–20.0 mm long, 2.0–18.0 mm wide; leaflet margins shallowly to deeply lobed; siliques 20.0–38.0 mm long	19
19	Leaf axillary and marginal hydathodes usually associated with additional hairs; sepals 2.4–3.2 mm long; petals obovate, 4.5–8.0 mm long, 2.5–3.6 mm wide	coronata
	Leaf axillary and marginal hydathodes solitary and not associated with additional hairs; sepals 1.3–1.6 mm long; petals narrowly obovate, 2.8–4.5 mm long, 0.7–1.4 mm wide	forsteri
20	Seeds winged	21
	Seeds not winged	23
21	Leaves membranous; silique 1.5–2.3 mm wide; seed oblong to oblong-elliptic, green to green-brown, wing at apex	unguiculus
	Leaves coriaceous; silique 1.1–1.9 mm wide; seed orbicular, broadly oblong to oblong, henna, wing at apex and lateral margin	22
22	Leaves glossy, terminal pinna usually with prominent triangular lobes, petiolule <2.5 mm long; inflorescence up to 120 mm long; petals 2.6–7.5 mm long, 0.8–3.8 mm wide; seeds 0.9–1.5 mm long	alalata
	Leaves matt, terminal pinna usually irregularly lobed, petiolule 2.0–15.0 mm long; inflorescence up to 350 mm long; petals 5.0–11.0 mm long, 2.5–5.5 mm wide; seeds 1.2–2.1 mm long	verna
23	Siliques hairy	24
	Siliques glabrous	28
24	Silique hairs sparse, patent, 0.35–0.6 mm long	hirsuta
	Silique hairs moderate to dense, appressed to spreading, up to 0.35 mm long	25
25	Petals 4.5–8.0 mm long, 2.5–3.6 mm wide; sepals 2.4–3.2 mm long, 1.1–1.3 mm wide; median filaments 2.5–4.0 mm long	coronata
	Petals 2.7–4.5 mm long, 0.7–1.4 mm wide; sepals 1.2–1.9 mm long, 0.5–0.9 mm wide; median filaments 1.6–2.7 mm long	26
26	Leaves 2.6–7.0 mm long, 3.2–10.0 mm wide, petiolule 0.5–5.3 mm long; petals 2.7–3.5 mm long, 0.7–0.8 mm wide; anthers cream to pale yellow or maroon	bisetosa
	Leaves 3.1–25.0 mm long, 4.7–25.0 mm wide, petiolule 2.0–16.0 mm long; petals 3.0–4.5 mm long, 0.7–1.4 mm wide; anthers cream or pale yellow	27
27	Sepals 1.7–1.9 mm long; median filaments 2.6–2.7 mm long, lateral filaments 2.2–2.3 mm long; silique 1.0–1.4 mm wide; seeds 1.0–1.2 mm long	intonsa
	Sepals 1.3–1.6 mm long; median filaments 1.6–2.5 mm long, lateral filaments 1.6–2.0 mm long; silique 0.7–1.1 mm long; seeds 1.2–1.4 mm long	forsteri
28	Inflorescence corymbose	29
	Inflorescence racemose	40
29	Petals >6.5 mm long	reptans
	Petals <6.5 mm long	30
30	Petals <3.5 mm long	31
	Petals 3.5–6.5 mm long	33
31	Leaves membranous, green or green-brown, terminal leaflet usually broader than long, adaxial surface usually sparsely to moderately hairy, margins with conspicuous patent hairs; sepals 0.4–0.6 mm wide, with conspicuous spreading hairs; siliques 0.7–0.8 mm wide, usually red-brown, weakly torulose, seed outlines usually visible through valve walls; seeds 0.5–0.7 mm wide	heleniae
	Leaves coriaceous or semi-coriaceous, green, terminal leaflet usually with ± equal length to width or longer than broad; adaxial surface glabrous, margin sometimes with a few sparse, inconspicuous hairs; sepals 0.5–1.0 mm wide, usually glabrous; siliques 0.9–1.5 mm wide, green, not torulose, seed outlines not visible through valve walls; seeds 0.9–1.0 mm wide	32
32	Leaves with conspicuous marginal hydathodes, terminal leaflet 3.0–11.0 mm long, 1.5–8.0 mm wide; siliques 5.7–14.0 mm long; style 0.3–0.5 mm long	exigua
	Leaves with inconspicuous marginal hydathodes, terminal leaflet 1.5–2.5 mm long, 1.0–2.5 mm wide; siliques 13.0–25.0 mm long; style 0.9–1.5 mm long	parvula
33	Terminal leaflet longer than wide, base attenuate to cuneate, occasionally obtuse	34
	Terminal leaflet similar length to width, base obtuse, truncate or cordate	35
34	Leaves usually simple, seldom pinnate, green, membranous, glabrous or sparsely hairy, with 0–2 lateral pinnae; terminal pinna oblong-elliptic, broadly oblong-elliptic to oblong-orbicular, base cuneate to occasionally obtuse; peduncle up to 150 mm long, glabrous; silique 9.0–20.0 mm long	integra
	Leaves usually pinnate, seldom simple, green to green-brown, ± coriaceous, glabrous, with 0–6 lateral pinnae; terminal pinna elliptic, broadly elliptic, obovate, ovate or spathulate, base attenuate to cuneate; peduncle up to 30.0 mm long, glabrous or hairy; silique 6.0–11.0 mm long	mutabilis
35	Leaves coriaceus	36
	Leaves membranous	37
36	Leaves green-brown to purple-brown, lateral pinnae 0–2; terminal pinna 2.0–6.0 mm long, 1.8–8.0 mm wide; sepals 1.8–2.4 mm long; siliques 12.0–20.0 mm long	serpentina
	Leaves green to green-brown, lateral pinnae 0–4; terminal pinna 2.0–25.0 mm long, 2.0–30.0 mm wide; sepals 2.3–3.0 mm long; siliques 20.0–40.0 mm long	glara
37	Sepals 1.1–1.6 mm long; silique 8.0–13.5 mm long	unicaulis
	Sepals 1.3–3.0 mm long; silique 12.0–32.0 mm long	38
38	Inflorescence up to 180 mm long, with 1–9 corymbs, corymbs 2–19‑flowered, occasionally with solitary flowers; leaf terminal pinna 3.0–27.0 mm long, 3.0–30.0 mm wide	grandiscapa
	Inflorescence with 1–3 corymbs, corymbs 2–8-flowered, often with solitary flowers; leaf terminal pinna 2.0–18.0 mm long, 2.0–16.0 mm wide	39
39	Leaves light green, leaf margin usually shallowly sinuate; sepals 1.8–2.2 mm long; petals 2.1–3.0 mm wide; silique style 0.8–1.0 mm long	sinuatifolia
	Leaves green, leaf margin entire; sepals 1.4–2.0 mm long; petals 1.8–2.3 mm wide; silique style 0.2–0.4 mm long	corymbosa
40	Lateral pinnae ≥10	41
	Lateral pinnae ≤8	43
41	Terminal pinna 3.4–4.7 mm long, 3.5–4.1 mm wide; inflorescence up to 50 mm long; silique 1.7–2.2 mm wide	latior
	Terminal pinna 2–25 mm long, 2–27 mm wide; inflorescence up to 350 mm long; silique 1.0–1.7 mm wide	42
42	Leaf terminal pinna larger than lateral pinnae; sepals 2.5–4.0 mm long, 1.0–2.4 mm wide; petals 7.0–11.0 mm long, 2.1–6.0 mm wide; median filaments 3.2–4.0 mm long, lateral filaments 2.0–2.7 mm long; seeds 1.5–1.7 mm long	pratensis
	Leaf terminal pinna similar size to lateral pinnae; sepals 1.5–3.5 mm long, 0.7–1.4 mm wide; petals 2.5–4.0 mm long, 1.0–1.7 mm wide; median filaments 2.3–2.4 mm long, lateral filaments 2.7–2.7 mm long; seeds 0.8–1.0 mm long	flexuosa
43	Lateral pinnae ≤2	44
	Lateral pinnae ≥3	46
44	Leaves coriaceous, grey-green to blue-grey, broadly ovate or broadly orbicular-deltoid, base truncate; sepals sparsely hairy	caesiella
	Leaves membranous, green, pandurate, pandurate-orbicular or rhomboid-pandurate, base cordate; sepals glabrous	45
45	Sepals 2.7–3.1 mm long; petals 6.0–7.0 mm long, 4.2–4.5 mm wide; silique 2.1–2.4 mm wide; embryo cotyledons without coloured veins	megalantha
	Sepals 2.0–2.4 mm long; petals 4.1–4.5 mm long, 1.9–2.3 mm wide; silique 1.1–1.3 mm wide; embryo cotyledons with violet-purple veins	porphyroneura
46	Anthers maroon or violet	47
	Anthers cream, yellow, pale yellow, sometimes flushed maroon	49
47	Lateral pinnae up to 8, petiolules 3.0–20.0 mm long; seed 1.2–1.8 mm long	coronata
	Lateral pinnae up to 4, petiolules 0.1–1.5 mm long; seed 0.8–1.3 mm long	48
48	Leaves glossy; terminal leaflet orbicular-reniform to deltoid-reniform, base strongly cordate to occasionally ± truncate; cauline leaves 2.0–3.5 mm wide	basicola
	Leaves matt; terminal leaflet orbicular-pandurate, weakly pandurate to orbicular-rhomboid, base obtuse, truncate or weakly cordate; cauline leaves up to 1.5 mm wide	dactyloides
49	Petals >4.5 mm	50
	Petals <4.5 mm	54
50	Silique width >1.5 mm	51
	Silique width <1.5 mm	52
51	Leaves coriaceous, lateral pinnae 2–6; terminal pinna 3.0–7.0 mm long, 2.8–8.6 mm wide, 1–3 marginal hydathodes; petals 4.2–7.0 mm long, 0.9–2.0 mm wide; siliques 1.5–2.0 mm wide; seeds 1.0–1.4 mm long, reticulate cells conspicuously thick-walled	eminentia
	Leaves membranous, lateral pinnae 1–2(–4); terminal pinna 4.7–36.0 mm long, 5.5–33.0 mm wide, up to 11 marginal hydathodes; petals 7.5–9.0 mm long, 2.5–5.0 mm wide; siliques 1.8–2.5 mm wide; seeds 1.8–2.2 mm long, reticulate cells not obviously thick-walled	polyodontes
52	Sepals 1.2–1.6 mm wide; ovules 22–28; silique style 0.7–1.2 mm long; seeds green	chlorina
	Sepals 1.0–1.3 mm wide; ovules 8–20; silique style 1.2–8.5 mm long; seeds henna	53
53	Siliques 1.0–1.2 mm wide; style 1.8–8.5 mm long; seeds 0.9–1.2 mm wide	dolichostyla
	Siliques 1.1–1.4 mm wide; style 1.2–2.5 mm long; seeds 0.6–0.9 mm wide	coronata
54	Sepals 0.3–0.7 mm wide	55
	Sepals 0.7–1.4 mm wide	57
55	Stamens 4 (rarely 5–6)	hirsuta
	Stamens 6	56
56	Annual herb; petals 1.8–2.3 mm long, 0.4–0.9 mm wide; silique style 0.3–0.5 mm long; seeds 0.7–0.9 mm long, 0.5–0.6 mm wide	occulta
	Perennial herb; petals 3.0–4.5 mm long, 0.7–1.4 mm wide; silique style 1.2–1.4 mm long; seeds 1.2–1.4 mm long, 0.6–0.9 mm wide	forsteri
57	Leaves membranous; inflorescence slightly flexuose	flexuosa
	Leaves coriaceous or subcoriaceous; inflorescence straight	58
58	Leaves sparsely hairy, green; silique 9.0–20.0 mm long, style 1.0–1.4 mm long	subcarnosa
	Leaves glabrous, grey to grey-green; silique 21.0–34.0 mm long, style 0.7–1.0 mm long	thalassica

Recognition

The following two tables provide habitat (Table 2) and character (Table 3) that may help distinguish between the species.

Synopsis of some major habitat types occupied and characters shared by species of *Cardamine* in New Zealand. o, obligate; f, facultative.
Habitat	Species
Alpine scree	C. alalata, C. eminentia, C. glara, C. parvula, C. serpentina, C. thalassica
Alpine bluffs, bouldery rubble	C. alticola, C. basicola, C. corymbosa, C. dimidia, C. intonsa, C. megalantha, C. sciaphila
Alpine wetland, seepages	C. exigua, C. reptans
Forest, shrubland	C. chlorina, C. corymbosa, C. dolichostyla, C. forsteri, C. intonsa, C. polyodontes, C. unguiculus
Limestone or marble	C. basicola (o), C. bilobata (f), C. bisetosa (o), C. caesiella (o), C. coronata (o), C. grandiscapa (f), C. integra (o), C. verna (o)
Low-elevation bluffs	C. dilatata, C. pachyphylla
River gravels	C. corymbosa, C. glara, C. verna
Shrubland, herbfield (main New Zealand islands)	C. corymbosa, C. dolichostyla, C. forsteri, C. polyodontes, C. unguiculus, C. unicaulis
Shrubland, herbfield (subantarctic islands)	C. corymbosa, C. depressa subsp. depressa, C. depressa subsp. stellata, C. latior, C. subcarnosa
Ultramafic outcrops	C. dactyloides (o), C. eminentia (f), C. porphyroneura (o), C. serpentina (o)
Weedy habitats occupied by indigenous species	C. corymbosa, C. forsteri, C. grandiscapa, C. heleniae, C. unicaulis
Weedy habitats occupied by naturalised species	C. flexuosa, C. hirsuta, C. occulta, C. pratensis
Wetland, seepages (often ephemeral)	C. cubita, C. exigua, C. lacustris, C. mutabilis, C. panatohea, C. reptans, C. sinuatifolia, C. unguiculus, C. unicaulis

Synopsis of some major characters shared by species of *Cardamine* in New Zealand.
Characters	Species
Anthers maroon or yellow and flushed maroon	C. basicola, C. bilobata, C. bisetosa, C. coronata, C. dactyloides, C. dilatata, C. dimidia, C. polyodontes
Hydathodes in leaflet axils	C. bisetosa, C. coronata, C. eminentia, C. forsteri, C. megalantha
Coriaceous leaves, usually with lobes	C. bilobata, C. dilatata, C. dimidia, C. pachyphylla
Glossy leaves	C. alalata, C. basicola, C. dimidia, C. eminentia, C. sciaphila
Pinnate leaves, membranous/subcoriaceous	C. alalata, C. bisetosa, C. chlorina, C. coronata, C. corymbosa, C. cubita, C. dactyloides, C. dolichostyla, C. exigua, C. forsteri, C. heleniae, C. integra, C. intonsa, C. lacustris, C. megalantha, C. mutabilis, C. porphyroneura, C. sinuatifolia, C. subcarnosa, C. unguiculus, C. unicaulis
Pinnate leaves, coriaceous	C. basicola, C. caesiella, C. eminentia, C. exigua, C. glara, C. grandiscapa, C. latior, C. parvula, C. reptans, C. serpentina, C. subcarnosa, C. thalassica, C. verna
Seeds with wings	C. alalata, C. eminentia, C. unguiculus, C. verna
Silique hairy	C. bisetosa, C. coronata, C. forsteri, C. hirsuta, C. intonsa
Simple leaves	C. alticola, C. basicola, C. depressa subsp. depressa, C. depressa subsp. stellata, C. mutabilis, C. sciaphila

Distribution

Cardamine is a worldwide genus that occurs on all continents with the exception of Antarctica (Al-Shehbaz et al. 2006). The New Zealand species occur on the main islands (North, South and Stewart Islands), numerous inshore islands (e.g., Hauraki Gulf islands), as well as many of the offshore islands such as Chatham Islands and the subantarctic Campbell Islands and Auckland Islands (Heenan 2017). They occur from the coast to the alpine zone, and occupy wetlands, forests, scree and rock bluff habitats.

Biostatus

Indigenous (Non-endemic)

Number of species in New Zealand within *Cardamine* L.
Category	Number
Indigenous (Endemic)	41
Indigenous (Non-endemic)	1
Exotic: Fully Naturalised	4
Total	46

Hybridisation

Cardamine verna × C. corymbosa. A single plant has features that indicate it may be a putative hybrid between C. verna (female) and C. corymbosa (male) (CHR 618326). This plant was collected from Isolation Creek, Marlborough, where it was growing among other seedlings of C. verna and with C. corymbosa growing nearby; this putative hybrid plant was cultivated at Lincoln. A hybrid origin is indicated by features of C. corymbosa, such as corymbose inflorescence; patent hairs on sepals and leaf margins; and rounded cauline leaflets. Features of C. verna include large and robust growth habit; leaves upright to spreading, brown-green, slightly irregular in shape, up to 120 mm long and coriaceous; and the inflorescences branched, upright, and up to 200 mm high. In addition, using Alexander’s Differential Stain, pollen stainability of the putative hybrid was moderate (54.7%), whereas plants of the putative parents from this site have high percentages of pollen stainability (C. verna 98.6%; C. corymbosa 99.6%).

Cardamine corymbosa × C. verna. Three plants have features that indicate they may be putative hybrids between C. corymbosa (female) and C. verna (male) (e.g., CHR 618324–618325). These plants were collected from Isolation Creek, Marlborough, where they were growing among other plants of C. corymbosa and with C. verna growing nearby; the putative hybrid plants were cultivated at Lincoln. These plants resemble C. corymbosa in having a compact growth habit; leaves low and spreading and with patent marginal hairs; corymbose inflorescences; and apetalous flowers. Features of C. verna include the robust growth habit; leaves up to 140 mm long and the leaflets irregularly shaped; and inflorescences up to 180 mm long. Using Alexander’s Differential Stain, pollen stainability of the three putative hybrids was low to moderate (27.4%, 29.4%, and 62.1%), whereas plants of the putative parents from this site have close to 100% pollen stainability (see above).

Bibliography

Allan, H.H. 1961: Flora of New Zealand. Vol. I. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. Government Printer, Wellington.

Al-Shehbaz, I.A.; Beilstein, M.A.; Kellogg, E.A. 2006: Systematics and phylogeny of the Brassicaceae (Cruciferae): an overview. Plant Systematics and Evolution 259: 89–120.

Garnock-Jones, P.J.; Johnson, P. N. 1987: Iti lacustris (Brassicaceae), a new genus and species from southern New Zealand. New Zealand Journal of Botany 25: 603–610.

Heenan, P.B. 2017: A taxonomic revision of Cardamine L. (Brassicaceae) in New Zealand. Phytotaxa 330(1): 001–154.

Heenan, P.B. 2020: Cardamine. In: Wilton, A.D. (ed.) Flora of New Zealand - Seed Plants. Fascicle 6. Manaaki Whenua Press, Lincoln.

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Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.

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