Sarracenia alata

Pale trumpets in many colors

Sarracenia alata has erect pitchers 15 to 75 cm tall, usually yellow-green in the upper tube and without the white windows of S. leucophylla ^[2]. The hood is broad and oval, 3.5 to 6 cm long by 4 to 6 cm wide. It sits on a short neck that is not pinched in, ends in a small point of 1 to 3 mm, and covers the mouth, which is 2 to 5 cm across with a tightly rolled rim ^[2]. Flora of North America (FNA) sums the species up as consistent in shape but extremely variable in color. Tubes and hoods can be plain, lined or netted with purple, or strongly purple throughout ^[2]. WCVP does not recognize the color varieties named for these forms, such as var. atrorubra, var. nigropurpurea and var. rubrioperculata, and lists them as synonyms ^[1].

The species is most easily confused with S. flava. FNA’s key separates them by the hood: in S. alata it is oval, usually wider than long, with no narrowed neck and edges that do not fold back. In S. flava it is nearly round, with lobes bent back and a pinched neck 1 to 3 cm long. S. alata also usually lacks the flat summer phyllodia that S. flava produces ^[10]. The confusion is old: in a 1998 review of S. flava names, Donald Schnell noted that the 19th-century S. flava var. crispata is clearly a description of S. alata ^[11]. WCVP lists that name as a synonym of S. alata ^[1].

Like S. leucophylla, this species makes a spring flush of pitchers and then a second, more robust flush in late summer; the late pitchers are the largest of the year ^[2].

Flowers and pitchers kept apart

Flowering is in March and April. The flowers have pale to deep yellow petals 5 to 7 cm long, a style disc 5 to 8 cm across and a moderately unpleasant scent, and sit on stalks 15 to 60 cm tall, shorter than the pitchers ^[2]. FNA notes they are shaped like those of the S. rubra group but larger ^[2].

The pitchers open shortly after the first flowers ^[2]. A study of two populations found that fewer than 1% of plants had open flowers and active pitchers at the same time. The author concluded this leaves little chance of the plant eating its own pollinators, though the timing may have evolved for other reasons ^[12].

A savanna plant shaped by fire

Field studies of S. alata show how much it depends on burning. After a prescribed winter fire in a Louisiana savanna, burned plots gained leaves while unburned plots lost them. More seedlings established in burned plots, and recruitment rose steeply with the number of flower stalks produced the year before the fire ^[13]. Fire and the removal of neighboring plants shifted growth toward pitchers and away from underground parts. The author suggested that adults tolerate crowding in years without fire by making fewer of their costly pitchers ^[14]. A later experiment found that the importance of carnivory to S. alata increases after fire ^[15].

The plants are long-lived. A demographic model projected a life expectancy of 59 years for large adult shoots, and population growth was much more sensitive to the survival of those adults than to fire-driven boosts in seedling establishment ^[16]. It is the only Sarracenia native to Texas ^[1]. There, FNA records it away from the longleaf pine savannas, in seepage bogs and meadows within dry oak country ^[2].

Populations split by rivers

Genetic work shows sharply separated populations. A 2012 study found that rivers are the main barriers, with populations on either side of the Mississippi diverging more than 60,000 generations ago ^[17]. Another study found western populations had shrunk while eastern ones had grown ^[5]. Isolated western sites showed little spread by rhizome and look like remnants of a once wider distribution ^[6]. Many of the small organisms living in the pitcher fluid share the genetic pattern of their host plants ^[18].

Sources differ on how much liquid the pitchers hold. A review of pitcher-plant fluids, citing a 1983 study, describes the pitchers of S. alata, S. flava and S. leucophylla as usually dry because the hood keeps out rain ^[19]. The genetic study above, by contrast, sampled organisms from fluid inside S. alata pitchers ^[18].

Not every visitor is prey. In a Texas bog, the specialist herbivore Exyra semicrocea had damaged about 86% of pitchers, eating on average 15% of each damaged pitcher and reducing plant growth ^[20].

Where S. alata meets other species it hybridizes. FNA lists wild crosses with S. leucophylla (S. ×areolata), S. purpurea (S. ×exornata) and S. rubra (S. ×ahlesii) ^[21].

Growing it

ICPS gives no separate guidance for S. alata, so the general Sarracenia method applies. That means full sun outdoors, pots 16 to 20 cm wide standing in 4 to 6 cm of low-mineral water, and a 1:1 peat and sand mix ^[8]. The guide groups the Gulf Coast taxa as warm temperate, expecting seasons but coping less well with hard freezes and short summers than inland and Atlantic species ^[8]. See the winter dormancy guide for overwintering in cold areas.

Its largest pitchers arrive in late summer ^[2], and old pitchers are worth leaving in place until they brown. ICPS says Sarracenia recover nutrients from old leaves. A field study found S. alata reclaims 38 to 42% of the nitrogen in a pitcher as it dies back, which the authors note is low compared with other carnivorous plants ^{[8, 9]}. Normal autumn browning is covered in Sarracenia pitchers turning brown. Mature clumps can be divided just before spring growth.