Yucca filamentosa ssp. concava

Yucca filamentosa ssp. concava ?  on Rhode Island Photo Tim Behan Copyright © 2001-2005

Synonyms:
Yucca concava Haworth, Suppl. Pl. Succ. 34  (1819)
Yucca concava Lemaire, III. Hort. 13:98 (1866)
Yucca filamentosa var. latifolia Engelmann, Trans. Acad. SCI. St. Louis 3: 52 (1873)
Yucca filamentosa var. concava (Haw.) Baker, Journ. Linn. Soc., Bot. 18: 228 (1880)
Yucca concava Hort. ex Baker in Journal. Linn. Soc. xviii. 228 (1880)
Yucca filamentosa forma concava (Haw.) Voss, Vilmorin Blumengarten (ed. 3) 1: 1057 (1895)

Clones, and Hybrids:
Yucca filamentosa ssp. concava  'albovariegata'

Type location:
Unknown to me!

Neotype:
USA, North Carolina, Alligator River 7. nov. 2000, Fritz Hochstätter, fh 1128.4, Boise State University, Idaho, (SRP).

Distribution:
In small colonies on coastal plains in North Carolina and South Carolina. Many populations are endangered by the expanding cities!

Short description of the species:
Acaulescent, spreading by short stolons (rhizomes).
Leaves: leaves rather firm, erect or spreading, Liniar-spathulate, acute, 20 - 40 cm long., 15 to 60 mm wide (up to 100 mm acording to Trelease 1902!), with many rather thick curly fibers at the margin of the leaves, the back is roughened in lines.
Inflorescence: glabrous flower stalk (starting as pubescent but later the "hairs" fall of and the stalk is smooth!) 120 to 250 cm tall, with short branches 5 to 15 cm long. Scape: is held high above the leaves.
Flowers: white, 3 to 5 cm across.
Fruit: The young capsule is apple-green, and has a rounded (convex) back, 20 - 40 mm long, brown when ripe.
Seeds: black, dull, 3-5 x 6 mm.

Hardiness:
Yucca filamentosa ssp. concava may be almost hardy here in Denmark, but will probably need to be protected against winter moisture with a sheet of glass.

Notes:
Take a look at Benny's "key" to the Yucca filamentosa & Yucca flaccida complex.

My own plants of this species:
(There are thumbnailed pictures on each page with hypertext)

#1517 Yucca filamentosa ssp. concava, Florida, Brooksville, fh 1182.10, sown 2002
#1516 Yucca filamentosa ssp. concava, Florida, Clermont City, fh 1182.9, sown 2002
#1518 Yucca filamentosa ssp. concava, Florida, Lake Panasoffkee, fh 1182.11, sown 2002
#1519 Yucca filamentosa ssp. concava, Florida, Lake city, fh 1182.12, sown 2002
#1514 Yucca filamentosa ssp. concava, North Carolina, Alligator River, fh 1182.4, sown 2002
#1515 Yucca filamentosa ssp. concava, North Carolina, Cap Fear River, sea level, fh 1182.5, sown 2002
#1513 Yucca filamentosa ssp. concava, North Carolina, Kitty hawk, sea level, fh 1182.3, sown 2002
#1512 Yucca filamentosa ssp. concava, Virginia, Cap Henry, Sea level, fh 1181.99 sown 2002

Reference:
BAKER, J. G., Linnean Society Bot. Journ. Vol. 18:228 (1881) (Yucca filamentosa var. concava)
HOCHSTAETTER, F., Kaktusbluete 18 :10 (2001) (Yucca filamentosa ssp. filamentosa)
HOCHSTAETTER, F., Kaktusbluete 18 :11 (2001) (Yucca filamentosa ssp. concava)
HOCHSTAETTER, F., Kaktusbluete 18 :11 (2001) 18 :10 (2001) (Yucca filamentosa ssp. smalliana)
HAWORTH, Synopsis Plantarum  Succulentarum Suppl. 34 (1819)  (Yucca concava)
HAWORTH, Synopsis Plantarum  Succulentarum Suppl. 34: (1819) (Yucca filamentosa var. concava Haw.)
TRELEASE, W. Mo. Bot. Gad. Ann. Rpt. 13: 1902
VOSS, Vilmorin Blumengarten (ed. 3) 1: 1057 (1895)  (Yucca filamentosa fa. concava)

Special thanks to Fritz Hochstätter, Steve Jankalski and Dave J. Ferguson for all their help with the Yucca filamentosa mess.