CURRENT NAME: Costus leucanthus X laevis
PROPOSED NAME: Costus leucanthus X kuntzei
NAME CHANGE NOTES: Unnamed natural hybrid found by Maas and Plowman
FULL SCIENTIFIC NAME:
STATUS :unnamed hybrids
This plant was found in 1974 in Colombia by Paul Maas and Tim Plowman along the new road between Cali and Buenaventura near the type collection for Costus leucanthus. It was collected as Maas number 1968 and seeds were distributed to Waimea Arboretum where it was accessioned as 74s1671. David Orr reports that his accession died in 2008.
The plant is still growing at Lyon Arboretum where their number is L-80.702. Per Ray Baker's notes, they received it from Waimea without data, as a "large Costus by stream". Ray Baker's note: " I dug this up near the stream at Waimea but we couldn't find a label." He described it as "Stems 4 m height, robust, 4 cm diameter at base. Leaves elliptic-oblanceolate, 30 cm long. Inflorescence ovoid-ellipoid, up to 12 cm long, 5 cm diameter; bracts dark red w/yellow midstripe. Flowers large, showy; corolla 8 cm long, pale yellow." The photos in his PDF sheet match the plant I saw in 2022 still growing at Lyon Arboretum, which is where most of the photos for this collection were taken.
I took a tissue sample for DNA analysis and made a voucher specimen for Cornell University herbarium BH. My record number for this is R3544, but I do not have it growing in my own garden.
It is an unusual looking Costus with light green bracts and with open labellum flowers in which the corolla lobes flare out much like the species Costus leucanthus. I have compared this against the 1974 photos that Paul Maas took at the collection site and against the herbarium specimens at Leiden and at the U. S. Herbarium in the Smithsonian. In the written description on the tag it describes this as "Herb to 4 m tall, bracts green, calyx and bracteole pale pink, apex green, corolla deep pink, labellum (ca 50 X 40 mm) dark vine red, yellow in the middle, stamen pinkish red, apex yellow"
The Maas photos for this hybrid are confusing because they include a photo of the actual species C. leucanthus along with a photo of Tim Plowman standing next to what is supposed to be this plant. Also there is a photo of a flower and bract on a leaf that is supposed to be this hybrid. These photos differ somewhat from the plant grown at Lyon Arboretum, but are similar by the usual flared out corolla and by the pale pink calyx and bracteole - both of which are unusual in Costus. It is possible that seeds from the hybrid produces the differences in coloration.
Further confusion results from the plant found in the conservatory at Utrecht, the Netherlands (No. 1974GR00544), which has a sign for this collection, but the plant growing behind the sign is a different Plowman collection of the new species Costus gibbosus.