Geniostoma imadae (Loganiaceae), a new single-island endemic species from Kaua‘i, Hawaiian Islands Author Wood, Kenneth R. 0000-0001-6446-1154 National Tropical Botanical Garden, 3530 Papalina Road, Kalāheo, HI 96741, USA Author Lorence, David H. 0000-0002-6735-9531 National Tropical Botanical Garden, 3530 Papalina Road, Kalāheo, HI 96741, USA Author Wagner, Warren L. 0000-0001-5012-8422 Department of Botany, Smithsonian Institution, PO Box 37012, Washington, DC 20013 - 7012, USA Author Fawcett, Susan 0000-0001-5021-1779 National Tropical Botanical Garden, 3530 Papalina Road, Kalāheo, HI 96741, USA & University and Jepson Herbaria, 1001 Valley Life Sciences Building # 2465, University of California, Berkeley, California 94720 - 2465, USA text PhytoKeys 2025 2025-06-10 257 191 207 journal article 310383 10.3897/phytokeys.257.154236 9e98280d-9b0d-4ddf-b847-e0586e63b269

Table 1. Comparison of morphological characters for all nine species of Geniostoma on Kaua`i.

	G. imadae	G. degeneri	G. helleri	G. hirtellum	G. lorencianum	G. lydgatei	G. pumilum	G. tinifolium	G. waialealae
Pubescence on young stems	glabrous	hispidulous or glabrate	glabrous	hirtellous	tomentose	hispidulous	glabrate	glabrous	hispid
Young stems angled, winged, or terete	terete	terete or weakly angled	terete	sharply angled to winged	terete	sharply angled	sharply angled to winged	terete	angled
Pubescence on abaxial leaf surface	glabrous	hirtellous	glabrous	hispid	tomentose	hispidulous	glabrous	glabrous	hispidulous
Leaf base	cuneate to acuminate	subtruncate to cuneate	cuneate	cuneate	cordate to auriculate	attenuate To cuneate	cuneate	cuneate	cuneate
Stipule length	4–8 (– 11) mm	6–11 mm	1–5 mm	2–6 (– 8) mm	1.5–2 mm	4–5 mm	5–9 mm	1–4 mm	1.8–2.5 mm
Stipule pubescence	glabrous	glabrous	glabrous	glabrous	hirsute to tomentose	glabrous or hispidulous	glabrous	margins ± ciliate	hispidulous
Peduncle length	(15 –) 20–75 mm	sessile	5–20 mm	sessile	20–60 mm	sessile	0–6 mm	9–35 mm	subsessile
Flower #	3–10	3–10 (– 15)	3–9	(3 –) 6–25 (– 50)	3–34	6–20	1–15	(3 –) 9–12 (– 19)	3–12
Corolla shape & color	salverform, orange-yellow	salverform, orange-yellow	urceolate, white or pale green-yellow	salverform, green-yellow or yellow-orange	urceolate, green	salverform, pale yellow	salverform, orange	urceolate, green-yellow	salverform, yellow
Corolla tube length	8–12 mm	10–11 mm	7–8 mm	(11 –) 14 – 23 (– 28) mm	10–13 mm	4 mm	9–10 mm	5.5–7.8 mm	5.5–10 mm
Corolla lobe length	9–11 mm	8–10 mm	2–3.5 mm	7–15 (– 18) mm	1.4–1.7 mm	2.5–3 mm	5–7 mm	1.7–2.3 mm	3–5 mm
Calyx lobe length	5–9 mm	6–15 mm	1.7–2.5 mm	3–10 mm	2.0–2.7 mm	1.5–2 (– 2.5) mm	6–11 mm	1.5–3 mm	3–6.5 mm
Calyx lobe width	0.8–3 mm	3–4 mm	0.8–1.3 mm	0.8–2 (– 2.5) mm	0.9–1.3 mm	0.5–0.8 mm	2–3 mm	0.7–1.6 mm	0.4–1.2 mm
Capsule valves	transversely wrinkled	transversely wrinkled	longitudinally striate	transversely wrinkled	longitudinally striate	transversely wrinkled	transversely wrinkled	transversely wrinkled	transversely wrinkled
Capsule length	10–15 mm	20–30 mm	9–20 mm	15–34 mm	25–37 mm	3.5–4 mm	9–14 mm	8–17 mm	9–15 mm
Capsule w / keel	no	yes	no	no	no	no	yes	yes	yes
Capsule valves	2 - valved	2 - valved	2 (3) - valved	2 (3) - valved	2 - valved	2 - valved	3 - valved	2 (3) - valved	2 (3) - valved
Capsule beak length	2–4 mm	1–2.5 mm	0.7–1.2 mm	(1.5 –) 2.5–6 mm	3.5 mm	0.2–0.3 mm	1.5–2.5 mm	0.5–1.5 mm	0.2–1.8 mm