Hypericum lobocarpum (Nomenclature)
Shrub 0.9-1. 5(-2) m tall, erect, with branches erect, forming large clumps. Stems reddish, 4-lined and ancipitous when young, soon 2- lined and rounded, becoming reddish brown and terete in 2nd season; cortex exfoliating in strips; bark smooth, thin. Leaves sessile or with pseudopetiole up to 5 mm long, often in axillary clusters; lamina 35-50 x 3-10(-14) mm, narrowly oblong to oblanceolate or linear, with margin recurved to revolute, paler or glaucous beneath, chartaceous, deciduous at basal articulation, apex apiculate-obtuse or apiculate-rounded to subacute, base narrowly cuneate to attenuate; venation obscure beneath: c. 12-14 pairs main laterals, with subsidiaries and densely reticulate tertiaries usually not or incom- pletely discernible, only midrib prominent; laminar glands dense. Inflorescence c. 5-25-flowered, without accessory flowers, with 3-15-flowered dichasia from 1-3 nodes below and sometimes flowering branches from lower nodes, the whole globose-cylindric to shortly and broadly pyramidal; pedicels 1.5-3 mm long; bracts reduced, elliptic to oblanceolate-spathulate or linear. Flowers 10-15 mm in diam.; buds broadly ovoid to subglobose. Sepals 5, (3.5-)4-4.5 x 0.8-1. 5(-2) mm, subequal to equal, not enlarging but divergent to reflexed in fruit, narrowly elliptic to narrowly oblong or oblanceolate-spathulate, apiculate to acute, margins revolute, basal veins 3-7, branching distally. Petals 5, golden yellow, becoming incurved-deflexed, 6-7(-8) x 2.5-3.5 mm, obovate-oblanceolate with apiculus lateral, acute. Stamens c. 100-150, longest 5-6.5 mm, 0.8-0.85 x petals. Ovary (3)4-5-merous, 2.5-3.5 x 1-1.5 mm, narrowly ovoid, acute; placentation incompletely axile; styles (3)4- 5, 2-3 mm long, 0.8-0.85 x ovary, remaining erect, separating only as fruit matures. Capsule 5.5-7 x 2.5-3.5 mm, narrowly ovoid-conic to ovoid, acute to subacute, (3)4-5-lobed, exceeding sepals, thinly coriaceous. Seeds blackish brown, 1.2-1.5 mm long, not carinate; testa linear-reticulate.
2n = 18 (n = 9) (Hoar & Haertl, 1932).
Rocky river bottoms and banks, lake margins, swamps and open Pinus woods; lowland up to c. 500 m.
South-eastern U.S.A. from south-eastern Oklahoma and eastern Texas to southern Illinois, western Kentucky, eastern Alabama and southern S. Carolina.
The status of 4. H. lobocarpum in relation to 5. H. densiflorum has been debated. Gattinger originally described it as a species, but Svenson (1940), when reducing it to varietal status under H. densiflorum, pointed out that the two taxa could not be separated on leaf width or habitat and that the numbers of styles and capsule valves were only relatively different. Adams (1962), on the other hand, while agreeing that style number was not diagnostic, reported that 92.1% of his H. densiflorum sample had a 3-merous ovary, whereas 79.1% of his H. lobocarpum ovaries were 5-merous and a further 19.2% were 4- merous, i.e. 98.3% were 4- or 5-merous. Taken in conjunction with their apparently distinct distributions (separated by 240 km in Mississippi/Alabama) and difference in capsule lobing, these differences appeared to warrant recognition of these taxa as species. Recent collections have included specimens of undoubted H. lobocarpum from western Alabama and S. Carolina (see above), although Adams (1973) did express doubt about the identity of the S. Carolina population; and other specimens from Alabama tend to have some intermediate characters (e.g. Kral 43501 (BM) from Marengo Co., W. of Demopolis). Nevertheless the geographical variation trends in each taxon are suggestive of original total separation and later introgression rather than incomplete separation. If this is so, then the Alabama intermediates should be regarded as hybrids. At any rate, it seems best to maintain these taxa as species, at least until a field analysis of the Alabama populations is made. [S. Crockett redetermined S. Carolina, Alabama andTennessee specimens as H. densiflorum]
? H. rostratum Raf. was described by C.C. Robin (1807) as related to H. galioides, and Rafinesque (1817) gave a Latin translation of Robin's French description. Svenson (1940) suggested that H. rostratum Raf. is probably an earlier name for H. lobocarpum, a suggestion with which I agree. Adams (1962: 50) also agreed; but he stated that, in the absence of a type, it should be rejected (as a nomen dubium) in the interests of nomenclatural stability. This would appear to be the sensible course to take, and I have therefore adopted the first undoubted name for this plant.