Osmunda regalis var. spectabilis

Osmunda regalis L. var. spectabilis (Willd.) A. Gray
(sp.: Latin: regalis or regius, royal, from rex, regis, king; var.: Latin: spectabilis, notable, showy, spectacular)

Local names: royal fern, flowering fern

Rhizome stout, woody, creeping to suberect; leaves erect to spreading, in a vase-shaped cluster, hemidimorphic (= partly dimorphic, with very different sterile and fertile pinnae on the same leaf blade), 2-pinnate; sterile leaves ca. 0.75–1(+) m long; pinnules lanceolate, mostly ca. 4–6 cm long, the margins subentire to remotely dentate, apically acute to rounded; pinnae without a persistent tuft of tomentum at base, essentially glabrous; fertile leaves similar to sterile except with greatly reduced, sporangia-bearing pinnae at tip; sori absent, the sporangia clustered, initially green, brown at maturity; 2n = 44 (Whetstone & Atkinson 1993). Wet areas; mainly Pineywoods and Post Oak Savannah w to Lamar Co. (W.R. Carr & D. Wolfe 13739, TEX-LL; Carr 1994) in Red River drainage and Travis Co. (Bray & Long s.n., Feb 1901, TEX-LL) on e edge of the Edwards Plateau; also slightly disjunct to Bexar Co. (Turner et al. 2003) to the sw and to Victoria Co. (Turner et al. 2003) in the Gulf Prairies and Marshes; se Canada and through e U.S. w to MN, OK, and TX; also West Indies, Bermuda, s Mexico to South America. Sporulating Mar–Jul. Variety regalis is native to Eurasia and Africa and is distinguished by black hair-like scales along the leaf rachis and a more robust habit (Nauman et al. 2000). There is debate regarding the correct taxonomy for O. regalis and its close relatives. For example, Mickel and Smith (2004) noted that “New World material looks distinct enough to be treated as a different species from O. regalis sensu strict (Old World), but more study of both herbarium and living material is needed to properly delimit these taxa. Metzgar et al. (2008) found evidence suggesting that O. regalis var. spectabilis (North America) might be more closely related to O. japonica and O. lancea (Asian species) than to the European O. regalis var. regalis. Further study is clearly needed to clarify these relationships. When this species complex is considered as a unit it demonstrates an Arcto-Tertiary distribution (see pages 12 and 33 for a discussion). Recently, a new tetraploid species of hybrid origin between O. regalis and O. japonica was described from Asia (Tsutsumi 2011). The Bexar and Victoria populations are somewhat disjunct from the remainder of the TX populations and may represent remnant populations surviving in isolated favorable microhabitats since Ice Age times (see page 36 for a discussion). Numerous such examples of disjunct species are known in TX (Kral 1966; MacRoberts & MacRoberts 1997a; Diggs & O’Kennon 2003; Taber 2008). Also see page 37 for a possible explanation of the TX-s Mexico disjunct distribution of both this species and Osmundastrum cinnamomeum. Whetstone and Atkinson (1993) noted that, “The chloroplasts within the spores give the young sporangia their green color. As the spores mature and are shed, the sporangia change color to a distinctive rusty brown.” This species is extremely distinct, particularly when in fertile condition. The fertile leaves are similar to the sterile except for the visually very obvious, greatly reduced, sporangia-bearing pinnae at the blade tip.

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